Buprestidae metamorphosis-inspired stiffening photonic elastomers for shape-color integrated memory and information encryption

Domain: chemistry
Published: 2025-12-26
Editorial outcome: minor_revision

Abstract
Integrating shape memory polymers into the device provides multi-functionality and recyclability. However, complex programming steps and the immutability of material properties hinder their applications. Here, inspired by the Buprestidae sclerotization process, linear long side chains are introduced into chiral liquid crystal elastomers (CLCEs), a class of polymeric photonic crystals, enhancing the phase transition tendency of the system. Through microphase separation between the more ordered structure (smectic and crystalline phases) and the primary chiral nematic (N*) phase, self-enhancement of the material is achieved at room temperature while retaining the selective reflection of the N* phase. Within 48 hours, the Young’s modulus increases by 1854%, and the strain energy density in the 0–100% strain range increases by 1533%. This induces a shape-color integrated memory effect which can be fully restored upon heating. Cyclic utilization of a single CLCE film is demonstrated through programming, achieving the memory of colorful shapes and high-fidelity textures. Furthermore, local regulation of microphase separation enables encrypted information writing and recycling.

Introduction
The rapid development of science and technology leads to a strong demand for new materials that can adapt to complex and diverse working environments. Shape memory polymers (SMPs) are key candidates for solving these challenges, with the programmability of temporary shapes being their significant advantage1–3. In recent years, numerous SMPs have been reported, such as shape memory hydrogels4–6, traditional polymers7–9, and liquid crystal elastomers (LCEs)10,11. As a major component of shape memory materials (SMMs), SMPs offer higher flexibility, economic feasibility, and diversity, making them highly promising for expanding the application scope of shape memory technology12–14.

LCEs, as special smart materials, possess the stimulus-response properties of liquid crystal (LC) materials and combine the extensible properties of elastomers. The differences in molecular chain arrangement and the degree of overall orientation of LCEs lead to different phases and properties. LCEs have advantages in feedback mechanisms in response to artificial intervention or environmental changes, with promising applications in fields such as actuators and soft robots15–19, sensors20–24, and information storage and encryption25–30. Given this background, how to utilize phase changes to impart shape memory while fully exploiting the special properties of LC materials is of profound significance. To construct SMPs, common and effective strategies include introducing dynamic covalent bonds31,32, utilizing supramolecular chemistry7,33, and enhancing crystallinity34,35. The first two strategies may involve complex synthesis processes or be sensitive to environmental factors, leading to material aging and reduced durability. The third is more compatible with the phase transition of LCs while avoiding complex synthesis steps, but there exists an inherent limited crystallinity of the material (especially in chiral systems).

Inspired by the metamorphosis of Buprestidae from larvae to imagoes (Fig. 1a), we note that the exoskeleton transforms from soft to rigid, preserving imago beetle’s shape. Concurrently, the hardening process retains the periodic stratified structures of chitin and cuticular proteins, stabilizing the structural coloration. Modulus determines the shape, and color acts as the medium for information, further combining the two may diversify the functionalities of SMPs. Drawing from this biological strategy, we aim to achieve memory of both three-dimensional (3D) shape and structural color through material hardening. Recently, it has been confirmed that introducing crystallizable chains in nematic LCEs induce some crystallinity36–39, and increasing the spacer chain length promotes the transition from nematic phase to smectic phase40,41. However, in chiral environments like chiral LCEs (CLCEs)—polymer-based photonic crystals with periodic structures and distinctive structural colors—the arrangement of LC units exhibits various ordering patterns, such as a helical structure (Fig. 1b, Bottom), which causes the arrangement of the crystallizable segments attached to both ends of the rod-like LC cores to deviate from the ordered arrangement of crystallization. And the crosslinked network of the elastomer restricts molecular chain motion, making the formation of crystalline (Cr) regions and the subsequent significant mechanical strengthening difficult in CLCEs, even if sufficient crystallizable components are introduced (Fig. 1b, Top). How to overcome these limitations and extend shape memory induced by phase transitions to chiral phases while fully utilizing the potential of LC materials remains great challenges.

In this study, we propose a practical approach to achieve intrinsic, one-way shape-color integrated memory in CLCE films through stiffness switching, which simultaneously integrates elasticity and plasticity. This material system is designated as stiffness-switchable CLCE (SS-CLCE). We achieve the formation of side chains with greater mobility by controlling the functional group relationships during the synthesis process to induce the main chains in a low-crosslink-density polymer network to participate in the transition from the chiral nematic (N*) phase to the partly-formed smectic C (SmC) phase, and the formation of crystalline phase of polymer chains, resulting in microphase separation in the CLCE (Fig. 1c). This microphase separation process is referred to as aging. The N* phase serves as the carrier of structural color, while the auxiliary SmC and Cr phases are the sources of the memory effect. Mechanical properties of the conventional CLCE remain unchanged before and after aging, whereas the SS-CLCE shows a considerable change (Fig. 1d). The initial N* phase is easily deformable, causing structural color changes, and after deformation, the material undergoes partial phase transition to the auxiliary phases at room temperature, resulting in increased stiffness and the simultaneous memory of shape and color changes. Finally, the material can be reset to its initial state by heating (Fig. 1e). Leveraging the above principle, we successfully realized shape-color integrated memory and demonstrated the application of rewritable encryption photonic paper. This SS-CLCE film avoids the issue of poor compatibility between different phases and allows the spontaneous memory process at room temperature, turning material aging into an advantage rather than a failure, enabling each phase of the material to perform its respective function in a single-layer, independent film.

Results
Materials synthesis and characterization
We prepared conventional CLCE and SS-CLCEs using the well-established anisotropic deswelling method42. The polymer films were obtained through a two-step crosslinking process. However, unlike previous work, this study employed a staged approach by sequentially using different solvents to optimize both solubility and polymerization temperature—initially enhancing raw material dissolution with dichloromethane (DCM), then maximizing heating temperature with ethyl acetate (EA). RM82 was used as the primary reactive LC monomer, LC756 as the reactive chiral dopant, ODT and EDDET as chain extenders, DPA as the catalyst for the chain extension reaction, and Irgacure 819 as the visible-light initiator for the homopolymerization reaction (Fig. 2a). The 1H NMR spectra of the main raw materials are shown in Supplementary Fig. 1. Complete names of all reagents and materials are listed in the Methods section.

EDDET was used as the chain extender for conventional CLCEs, while ODT was primarily used as the chain extender for SS-CLCEs. After the completion of chain extension, the obtained oligomers were dissolved in EA, poured into molds, and the solvent evaporation and self-assembly processes were then initiated. According to our strategy, most of the acrylate and thiol groups underwent addition reactions in the first chain-extended step, as confirmed by 1H NMR spectrum. In the second step, the remaining acrylate groups underwent homopolymerization, while the residual thiol groups indicated the presence of long side chains, as verified by Fourier-transform infrared spectroscopy (FTIR)43,44. Ultimately, a lightly crosslinked network incorporating long side chains was formed (Fig. 2b and Supplementary Fig. 2).

Conventional CLCE film was soft, highly elastic, and displayed bright selective reflection colors. Polarized optical microscopy (POM) images revealed a standard grainy texture42, indicating that the film was in the N* phase. Differential scanning calorimetry (DSC) curves showed no significant enthalpy changes, but a small endothermic peak was observed at 90 °C during the heating cycle, and a small exothermic peak appeared at 83 °C during the cooling cycle. These peaks suggested phase transitions of the long side chains near the isotropic transition point (Ti) (Fig. 2c).

Due to the long linear structure and crystallizable segment-containing characteristic of SS-CLCE oligomers, gradual self-assembly occurred during the evaporation film-forming process, leading to the formation of large-sized spherulites—which was detrimental to the integrity of the polymer film (Supplementary Fig. 3). Therefore, this gave rise to the discussion on the selection of appropriate self-assembly conditions. We selected 4 h (a duration with no macroscopic defects observed) as the self-assembly time prior to polymerization, the resulting SS-CLCE presented white, and showed a controlled rigidity that disappeared upon heating. POM images revealed a polydomain texture, suggesting the presence of phase separation. DSC curves further indicated that SS-CLCE had the mentioned isotropic transition of the side chains. Additionally, during the first heating cycle, two consecutive endothermic peaks were observed at 48 °C and 60 °C. Since a pronounced cold crystallization peak was observed at 43 °C (cold crystallization temperature, Tcc) during the second heating cycle, followed by a relatively small crystal melting peak, we believed that the second endothermic peak was associated with crystal melting temperature (Tm). The appearance of dual endothermic peaks is commonly explained by the sequential melting of different crystal structures45–49. We propose that the two endothermic peaks correspond to the disruption of structures with different degrees of order. Notably, the absence of a distinct exothermic peak during the cooling cycle suggested that the timescale for the main chain phase transition or crystallization was relatively long (Fig. 2d).

When the self-assembly time was further extended to 8 h or more, the influence of the auxiliary phase on the primary N* phase became significant, a large number of macroscopic defects (crystalline regions) are generated, which seriously affect the uniformity of the film. To prepare uniform elastomer films, a heating (100 °C) and cooling (68 °C) process was applied to eliminate crystalline regions before polymerization. The resulted CLCE was defined as the controlled CLCE (C-CLCE), which was induced into a vertical alignment mode due to the absence of orientation effect induced by evaporation. POM images revealed a chiral coil morphology, accompanied by the complete disappearance of selective reflection. The thermodynamic and mechanical properties of C-CLCE were nearly identical to those of SS-CLCE (Supplementary Fig. 4). All the thermodynamic data were shown in Supplementary Table 1.

Since the macroscopic properties of SS-CLCE resulted from the coexistence of the N* phase with other phases, we focused on it as the primary subject for subsequent research. Based on thermodynamic analysis, POM images of SS-CLCE were observed at different temperatures in the first heating cycle (Supplementary Fig. 5). The changes in color and brightness in the images indicated variations in the optical path difference (OPD) across different regions, reflecting the changes in the periodic structure of the material and the alteration of its phase state. It is noted that the performance difference between SS-CLCE and conventional CLCE indicated that the presence of ODT affected the ability to undergo phase separation. ODT segments not only enabled polymer crystallization themselves but also promoted the formation of the to-be-discussed smectic phase. This is because the rod-like cores of nearby LC molecules acquire the characteristic of orientational order along with the regular arrangement of crystalline molecular chains.

Structural causes of stiffness-switching performance
The rigidity of SS-CLCE films decreased after heating at 80 °C, as evidenced by a substantial reduction in Young’s modulus (E) and strain energy density (U) (Fig. 2e). Meanwhile, the sharp crystalline peaks in the X-ray diffraction (XRD) patterns clearly indicated the presence of crystallinity (X) of 26%, reflecting the volume proportion of crystalline regions in the polymer, with the remainder being LC phases and amorphous regions. We also fabricated a wedge-shaped film, and multi-point XRD tests demonstrated the uniformity of the microstructure across the entire film as well as the wide thickness range within which aging occurred (Supplementary Fig. 6). After heating, the crystalline features disappeared (Fig. 2f). We also ruled out the influence of residual monomers through the swelling experiment of SS-CLCE and the XRD pattern of the main monomer RM82 powder. The measured gel fraction (G) exceeded 78%, indicating a well-formed network structure (Supplementary Figs. 7 and 8). C-CLCE films exhibited the same trend, where crystallinity corresponded to the stiffness-flexibility switchability, while conventional CLCE films remained unaffected by thermal history (Supplementary Figs. 9 and 10). This suggested that phase separation—induced by ordered structures such as polymer chain crystallization and the retained N* phase—resulted in a 1000% increase in E for SS-CLCE, from 3.3 MPa to 36.1 MPa. The fracture energy increased from 494 MJ m-³ to 1391 MJ m-³, a growth of 180%. Since the fracture elongation of this material system was far lower than that of natural rubber (which exceeds 500%), only repeatable crystallization was observed, with no obvious strain-induced crystallization phenomenon (Supplementary Fig. 8).

To correlate the dual endothermic peaks in the DSC curve with structural changes in the material, we subjected SS-CLCE to heat treatments under different conditions, followed by rapid cooling to room temperature for FTIR testing, instead of performing in-situ variable-temperature infrared spectroscopy. This approach minimized the impact of the temperature responsiveness of the LC material on our analysis (Fig. 2g). When the material was heated to 53 °C or lower, no significant spectral changes were observed. This indicated that the first endothermic peak did not correspond to the disruption of a highly oriented or highly ordered structure. However, when the heat treatment temperature reached 80 °C—covering both endothermic peaks, the spectral features exhibited several pronounced changes, including peak broadening, shifting, and weakening. Specifically, the peak at 726 cm⁻¹ slightly weakened and broadened. This peak represents the backbone vibrations of long alkyl chain structures with more than four carbon atoms50, suggesting that the spacer chains of SS-CLCE underwent a transition toward disorder, corresponding to polymer crystal melting. The peak at 1472 cm-1, corresponding to the orthorhombic crystalline form of methylene, broadened upon heating, accompanied by the prominence of the 1466 cm-1 bending vibration, which corresponds to the “amorphous” state50,51. Decreases and shifts of multiple peaks at other positions were also observed (Supplementary Fig. 11), indicating that the second melting peak corresponded to the disruption of a significantly ordered structure—namely, the melting of polymer chain crystallites52–54. Furthermore, crystallization was not limited to the longer alkyl chains, the thioether (650 cm−1) and benzene ring structures within the polymer network also contributed to the formation of the ordered structure.

In-situ variable-temperature 2D wide-angle X-ray scattering (2D-WAXS) experiments were conducted to demonstrate molecular-level structural changes during the heating process of aged SS-CLCE (Supplementary Fig. 12). Four temperature points were selected for testing (Supplementary Fig. 13). The 2D patterns displayed arc-shaped peaks, which originated from the sample preparation process and was minimal, having no impact on the long-period structure of the sample (Fig. 3a and Supplementary Fig. 14). The temperature-induced pattern changes were easily observed. The crystalline peaks in the wide-angle region and the long-period peaks in the small-angle region were eliminated during heating, leaving only the characteristic diffuse peak at 1.41 Å−1, typical of LC materials. The 2D images were converted into 1D curves for further analysis (Fig. 3b–d). According to Bragg’s law, at the initial temperature of 30 °C, four crystalline peaks at scattering vectors of 1.34, 1.46, 1.56, and 1.68 Å−1 corresponded to interplanar spacings of 4.65 Å, 4.30 Å, 3.97 Å, and 3.72 Å, respectively. Based on the Scherrer equation, the corresponding crystallite sizes were approximately several to a dozen nanometers. (Supplementary Fig. 15a and Supplementary Table 2). Furthermore, adjusting the ratio during the synthesis process can regulate the crystallization properties, corresponding to the control of the crystallinity (Supplementary Fig. 15b). The long-period peak at 0.141 Å−1 corresponded to a 4.4 nm layered structure of LC units and spacer chains, which is typically indicative of a smectic phase in LC materials41. However, due to the polydomain nature and localized phase separation of the material, the smectic phase characteristics were not prominent (Fig. 3e). Due to instrument limitations, data below 0.05 Å−1 were invalid. It could be inferred that the peaks below 0.1 Å−1 corresponded to larger-scale periodic structures (>6.2 nm), typically representing the periodic distribution of ordered and disordered regions45.

As the temperature increased to 46 °C, the diffuse peak at 1.41 Å−1 continuously intensified, while the crystalline peaks showed a slight decrease. A minor shift was observed at 1.69 Å−1, which resulted from the overlapping intensity variations of multiple peaks rather than the actual shift of an independent peak. This indicated the melting of a small number of imperfect crystallites. Meanwhile, no decrease was observed in the small-angle peaks, suggesting that both types of long-period structures remained largely intact. At 53 °C (the final stage of the first endothermic peak and the early-to-mid stage of the second endothermic peak in the DSC curve), further crystal melting occurred. However, the intensity of peaks below 0.1 Å−1 did not decrease, indicating that the melting of a small number of crystallites did not disrupt the large-scale periodic distribution of ordered and disordered regions. Meanwhile, a 7 °C temperature increase led to a 50% reduction in the intensity of the smectic layering peak, suggesting that the latter stage of the first endothermic peak corresponded to the breakdown of the smectic phase. Finally, when the temperature reached 80 °C, all crystalline peaks disappeared, the periodic ordered-disordered structure was completely disrupted, and the smectic phase degraded into the N* phase55. Based on these findings, we inferred that the two independent endothermic peaks spanning 40 °C in the DSC curve corresponded to the phase transitions from the smectic phase to the N* phase and from polymer crystallization to the LC state, respectively. The enthalpy-change relationship corresponding to these two peaks implied the relative quantitative relationship between the smectic phases and the crystalline phases.

To confirm the existence of the smectic phase, we further calculated the energy-minimized structure of the LC monomer and chain extender using the MM2 force field (Supplementary Fig. 16). The molecular length of the LC unit was found to be approximately 3.8 nm, the chain extender’s molecular length was 1.2 nm, so the length of the extended unit was 5 nm, which was larger than the 4.4 nm interlayer spacing shown by WAXS. This suggests that the phase is SmC33,56. 2D small-angle X-ray scattering (2D-SAXS) tests were conducted on both the un-stretched aged sample and the aged sample at ε = 1.5, showing significant orientation differences (Fig. 3f and Supplementary Fig. 17). 1D data were obtained through integration, revealing only a slight change in the interlayer spacing, from 4.55 nm to 4.39 nm (Fig. 3g, top), which was the result of both chain extension and the directional change of the interlayer spacing. Additionally, a weak peak was observed at 1.7 nm, which was not visible in the wide-angle experiment due to its low intensity. This peak was unaffected by stretching orientation and may represent short-range ordering of LC units at covalent crosslinking sites. Azimuthal integration (Fig. 3g, bottom) showed that the orientation of the layered structure changed from the standard ring-like unoriented state to a double-dumbbell state, reflecting that stretching caused the layered structure to misalign, forming a V-shaped structure with an angle of 120°, indicative of the chevron SmC (cSmC) phase (Fig. 3h)57. Based on the periodic arrangement of semicrystalline polymer crystalline grains, intermediate phases, and amorphous regions58,59, we provided a schematic diagram of the molecular arrangement of the aged SS-CLCE in the un-stretched state, showing the molecular spacing data in different phase regions (Fig. 3i). In summary, SS-CLCE underwent diverse phase transition processes, where microphase separation occurred after aging, involving the primary N* phase, the auxiliary SmC phase, and chain crystallization. The coexistence of SmC and Cr in N* phase enabled physical crosslinking. While retaining partial LC properties, the material exhibits a significant increase in stiffness and can be softened by heating.

Mechanochromism and self-reinforcement effect of SS-CLCE
Due to the presence of the helical structure, CLCEs exhibit selective reflection of light, and the variation in reflected color is correlated with changes in the helical pitch (p) (Supplementary Fig. 18)60–62. In this study, microphase separation was achieved within the primary N* phase to obtain switchable mechanical properties while maintaining effective reflection color after stretching. A uniaxial stretching experiment was performed on SS-CLCE films after heating at 80 °C for 1 min (Fig. 4a). The initial film appeared white with a faint orange-red reflection, corresponding to a broad reflection peak around 630 nm. This is because the helical structures in the sample had uneven orientations and variations in p at different positions, influenced by the relatively weak orientation force of solvent evaporation during preparation. Meanwhile, the difference in refractive index for light among different microdomains leads to intense light scattering, exhibiting non-selective unpolarized light. Considering comprehensively, the white color under natural light is the combined result of unpolarized light scattering and broad-peak reflection of right-handed circularly polarized light. In the early stage of stretching, the surface alignment of the film improved, reducing diffuse reflection and enhancing the intensity of reflection in the perpendicular direction. When the strain increased to 60%, the alignment of the LC units was further optimized, resulting in a well-ordered perpendicular arrangement of the helical structure. Consequently, the broad-reflection feature diminished, and a single reflection peak at 560 nm (green) emerged. With further stretching, the peak became narrower as the film approached a monodomain state; consequently, the blue color became more vivid while the white background gradually faded. However, the overall reflectance decreased, indicating partial disruption of the helical structure. Overall, the color change in the film was uniform, demonstrating its soft-elastic behavior. It should also be noted that the structural color exhibited by SS-CLCEs has certain limitations compared with existing CLCEs, which is attributed to the molar ratio of acrylate to thiol (used for oligomer preparation) being close to 1:1, as well as the selection of the microphase separation strategy and the solvent evaporation method. The trade-off involved causes SS-CLCEs to sacrifice the quality of structural color in exchange for switchable mechanical properties63.

A different phenomenon was observed when a uniaxial stretching experiment was conducted on aged films (Fig. 4b). The initial color remained as a weak red reflection on a white background due to the polydomain structure. Due to the higher crystallinity, the aged film exhibited increased rigidity. In the early stage of stretching, stress concentration led to significant deformation at the film’s edges first, causing a sudden shift in reflection color to blue at the edges. As the applied stress increased, deformation gradually extended to the central part, reducing the polydomain regions. However, due to physical cross-linking, the stretching-induced alignment of LC units was restricted, leading to minimal changes in reflectance. Since the regions connecting the edges and the center displayed intermediate colors, we also collected the reflection data at the edge positions (Supplementary Fig. 19), these data reflected the differences between the center and the edge positions. In summary, SS-CLCE still exhibited controllable reflection colors within the visible spectrum. The reflection spectra of other samples are shown in Supplementary Fig. 20.

Heating eliminated phase separation, leading to material softening. Conversely, the softened material could undergo aging under certain conditions, resulting in an increase in stiffness. To investigate the time-dependent self-reinforcement effect, the tensile properties were tested for aging times ranging from 0 to 72 h, with the treatment temperature fixed at 20 °C (the second variable affecting the aging degree) to ensure a uniform aging rate. The stretching rate was fixed at 25 mm min−1. Since stiffness changes are primarily reflected in the elastic deformation region, the study focused on the strain range of 0 to 100% (Fig. 4c), although local preferential strain occurs during the process (local necking first occurs at a specific point), this is also a reflection of the overall performance. The material was tested after removing thermal history and cooling to room temperature, serving as the baseline data before aging. When the aging time was less than 8 h, the stress at 100% strain remained below 1 MPa, with a low modulus and a limited elastic deformation region. As the aging time increased, a distinct elastic deformation region emerged, and the modulus gradually increased. After 48 h, the stress at 100% strain reached 3.5 MPa, marking a 1066% increase compared to the no-aging value of 0.3 MPa. The E followed an S-shaped curve, indicating a slow-fast-slow trend in the physical cross-linking rate, peaking at 16 h before gradually approaching zero. The early-stage data points were densely distributed, clearly illustrating the mid-stage acceleration in cross-linking. After 48 h of aging, E increased from 2.2 MPa to 43 MPa, a rise of 1854%. The U exhibited a similar trend, increasing from 197 kJ m-³ to 3218 kJ m-³, an improvement of 1533%. These results demonstrate that the material’s stiffness and toughness significantly improve over time, highlighting its time-dependent self-reinforcement effect. Scanning electron microscopy (SEM) revealed the absence of helices in some regions, reflecting the cause of the self-reinforcement effect—namely, the presence of phase separation. SEM further demonstrated the distribution of p (Fig. 4d)64–66. To examine the mechanical performance potential of SS-CLCE, we set the aging time to two weeks and even five months for testing (Supplementary Fig. 21). The stress-strain curves indicated that after 2 weeks of aging, the Young’s modulus increased from 43.1 MPa (at 48 h) to 63.4 MPa. However, no significant increase in Young’s modulus was observed for the material aged for 5 months, with only a partial improvement in toughness. This phenomenon demonstrated that the SS-CLCE film still underwent a self-reinforcement process after 2 weeks. Nevertheless, after 48 h, the material required much more time (tenfold to hundredfold) to achieve a much smaller enhancement. The result was consistent with the S-shaped enhancement trend. Guided by the principle of efficiency, we selected 24 h or 48 h as the main research timeframes. The results showed that the material exhibited a self-enhancement effect over a long-time scale. As time progressed, the mechanical properties continuously improved, making aging an advantage rather than a failure process.

The DSC curves of SS-CLCE after aging for 48 h at different temperatures were compared (Fig. 4e). It was observed that as the aging temperature increased, both endothermic peaks shifted to higher temperatures. The SmC-N* phase transition peak maintained its shape, while the melting peak became sharper. Combined with XRD and WAXS data, these results indicated that within a certain range, higher temperatures lead to a more complete crystalline structure, increased grain size, reduced crystal plane spacing, and a narrower melting range, which aligns with general polymer crystallization behavior. Additionally, the enthalpy of fusion decreased from 19.43 J g−1 to 12.22 J g−1, corresponding to a reduction in phase separation, which could potentially lead to a decrease in mechanical performance. To further investigate the temperature-dependent self-reinforcement effect, the tensile properties of SS-CLCE films were tested at different temperatures with a fixed aging duration of 24 h to exploring the impact of temperature on the rate of aging. The stretching rate was fixed at 25 mm min-1 (Fig. 4f). The glass transition temperature (Tg) of the material is −12.2 °C. When the aging temperature was close to Tg, molecular chain motion was restricted, resulting in only a slight enhancement of the mechanical properties. As the temperature approached room temperature (20 °C), a significant improvement in mechanical performance was observed. When the temperature reached 30 to 40 °C, near the melting range, the mechanical performance peaked. When the temperature increased beyond the early stage of the melting range (50 °C and 80 °C), the mechanical reinforcement weakened. This phenomenon reflected that high temperature would also inhibit the occurrence of phase separation, further underscoring the importance of selecting an appropriate temperature for phase separation. (Supplementary Fig. 22). Despite this, the slope of the stress-strain curve at 50 °C increased significantly, suggesting the formation of more complete and larger crystalline structures.

In summary, we emphasized that the phase transition of LC polymer materials exhibits a dual dependence on both temperature and time. Unlike traditional studies on LC materials that focus solely on temperature as the determinant of phase state (Fig. 4g, top), we introduced time as a second dimension. At an optimal temperature, self-enhancement of mechanical properties can be achieved within a short time, whereas excessively low or high temperatures prolong or even prevent phase separation from occurring (Fig. 4g, bottom). Heated-aged cycle tests were conducted to demonstrate the stability of the self-reinforcement effect and the durability of the SS-CLCE. The mechanical properties after aging at different temperatures and the structural color after cycling both indicated the durability and fatigue resistance (Supplementary Fig. 23). This finding provides valuable insights for the controlled tuning of mechanical properties.

Shape-color integrated memory based on stiffness switching
The stiffness-switching capability of the material endows it with programmability. Just like the metamorphosis of Buprestidae (Fig. 1a), a soft, white larva evolves into a colored beetle with a hard exoskeleton after long-time sustained growth. Specifically, SS-CLCE can fully soften within 10 seconds when heated to 80 °C and remain flexible for the following 8 h at room temperature, attributed to the slow reinforcement rate in the initial stage of the S-shaped reinforcement process. The modulus remains relatively low within 8 h, allowing for large and complex deformations with minimal force. Certainly, the 8-h duration is merely a reasonable choice based on the reinforcement rate, it is not fixed and can be flexibly adjusted according to specific requirements. This period is defined as the programming region. Near room temperature, the material undergoes spontaneous phase transitions, forming physical crosslinks that enhance stiffness. The phase with a rapid increase in stiffness is defined as the crosslinking or setting region. When the crosslinking time exceeds 24 h, the material’s stiffness and mechanical properties have significantly improved, and the crosslinking rate slows down. Although the material has not yet reached its maximum mechanical strength, this duration balances time efficiency with mechanical enhancement, making it suitable for practical applications. Therefore, the region beyond 24 h is designated as the application region after programming (Fig. 5a). If the requirements change, reheating the material can return it to its initial state, enabling reprogramming. This defines the application logic of SS-CLCE materials.

First, a force test was conducted on strip-shaped film samples. In the aged state, the sample could withstand 1667 times its own weight without significant deformation, maintaining a white, multi-domain, rigid state. Upon heating, the sample instantly softened, stretched into a single-domain transparent state accompanied by a blue shift in the reflection color, and remained unbroken (Fig. 5b). When extensively heated, the film exhibited the same deformation behavior (Supplementary Movie 1). This clearly illustrated the difference in the mechanical properties of the material before and after aging. Next, we demonstrated the shape-color integrated programming process of SS-CLCE. The strip-shaped film served as the permanent shape, which could be molded into a shelf-shaped (temporary shape) after softening, displaying structural color changes due to deformation. After aging, the shelf regained stiffness and retained its structural color, capable of supporting a certain weight. Under excessive load, the shelf collapsed but could stand upright again once the weight was removed (Supplementary Movie 2). Throughout these processes, bending and tilting due to applied pressure were visibly reflected in the selective reflection colors. Upon reheating, the temporary shape was erased, restoring the permanent shape, which could then be reprogrammed into a spiral shape (temporary shape, Methods Section). This spiral shape was entirely composed of curved surfaces, exhibiting a rich structural color (Fig. 5c). It demonstrated a certain load-bearing capacity and could recover its spiral shape after being flattened and unloaded (Supplementary Movie 3). These demonstrations highlighted the stability and reusability of the shape-color integrated memory effect in SS-CLCE materials. Finally, a large-sized film (90 × 50 mm) was fabricated and programmed into the shape of the Monkey King’s facial mask (62 × 58 × 30 mm). The mask accurately retained the shape of facial features with fine pattern details (Fig. 5d). Upon heating, it was also capable of reverting to its original state, thereby enabling the next usage cycle. It is worth noting that the aforementioned programming time requires more than 24 h to achieve better memory effect. By introducing more crystallizable segments and increasing the aging temperature to accelerate chain rearrangement, the duration can be further shortened to 8 h (Supplementary Fig. 24).

Rewritable photonic paper for encrypted writing
The previously described whole-film processing of the film enabled the retention of both its 3D shape and structural color. In contrast, localized processing allowed for the recording of encrypted textual information. Previous work reported stiffness control via crosslinking degree: (1) using photomasks on single films to form deformation patterns via differential photopolymerization; (2) making matrices with small CLCE pieces of varying crosslinking degrees for regional color differences26,67,68. Similarly, differences in thickness will convert the same external force into different stresses, thereby resulting in color distinction during the stretching process69,70. These measures fixed film modulus, precluding erasure/rewriting (crosslinking control) or single-film color variation (dot matrix). While prior studies are valuable, our work enabled post-fabrication non-directional patterning via localized heating to reduce modulus. Heating the entire film and re-aging allowed rewriting, achieving write-erase on a single film without matrixization or custom photomasks.

As shown in Fig. 6a–b, the initially white film exhibited uniform color and modulus. By locally heating the film to 80 °C using a heating pen, the desired information was written, making the information section soft and more susceptible to stretching within a few hours. Although the modulus of the heated regions decreased, the apparent color remained white. At this moment, the information was in an encrypted state and cannot be observed. Only slight marks caused by excessive writing pressure may remain on the film surface. Due to the polydomain and phase-separated nature of the film, its non-selective broadband reflection hindered the readability of the recorded information. In this case, a right-handed circular polarizer (R-CP) is the first key to decrypt the information, the intensity of unpolarized reflection and scattering is reduced by half (left-handed polarization is blocked), and the intensity of right-handed polarized light centered at 630 nm, dominated by the N* phase, remains unaffected60,67. Thus, a distinct orange-red background was observed through a R-CP. Biaxial stretching as the second key induced uneven deformation in soft and hard regions, resulting in structural color variation that decrypted visual information. Subsequently, the self-reinforcement effect helped preserve the displayed information by maintaining external stress at 30 °C for 1 day. The film can recover after globally heating the film at 80 °C and leaving at 30 °C for one day, allowing for a new cycle of information encrypting. As an example, we successively wrote in the year “2025” and key material’s abbreviation “CLCE” (Fig. 6c). The modulus of the information-bearing regions was lower, resulting in greater deformation and a more pronounced blue shift in structural color, thereby displaying high-contrast yellow-green patterns under R-CP. Supplementary Movie 4 illustrated the process of information decryption.

Methods
Materials
In this study, 1,4-bis[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene (RM82, 95%) and 1,4:3,6-Dianhydro-D-glucitol bis[4-[[4-[[[4-[[1-oxo-2-propenyl]oxy]butoxy]carbonyl]oxy]benzoyl]oxy]benzoate] (LC756, 90%) were purchased from Kindchem (Nanjing) Co., Ltd. 1,8-octanedithiol (ODT, 98%) was purchased from Macklin. 3,6-Dioxa-1,8-octanedithiol (EDDET, 98%) was purchased from Energy Chemical. Dipropylamine (DPA, 99%) was purchased from Aladdin. Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Irgacure 819, 99%) was purchased from Heowns. Dichloromethane (DCM, >99.5%) and ethyl acetate (EA, >99.5%) were purchased from FUYU Chemical. All chemicals and reagents were used as received.

Synthesis of CLC linear oligomers
All the studied CLCEs were prepared based on a two-step crosslinking method, with the first step being the synthesis of oligomers. In the SS-CLCE and C-CLCE systems, the molar ratio of acrylate to thiol was 1:0.99. The molar ratio of RM82 (240 mg, 0.357 mmol) to LC756 (11 mg, 0.011 mmol), which provided acrylate functional groups, was 1:0.032, while the molar ratio of ODT (52.7 mg, 0.296 mmol) to EDDET (13.5 mg, 0.074), which provided thiol functional groups, was 1:0.25. For the conventional CLCE system, only EDDET (64.2 mg, 0.353 mmol) was used to provide thiol functional groups. All monomers were dissolved in DCM, 1.5 wt% DPA (excluding solvent mass, 5 mg, 0.049 mmol) was added, and 1.5 mL of DCM was used per 300 mg of solute for thorough mixing. The mixture solution was then placed in a glass dish at 33 °C, allowing the solvent to evaporate within 2 h while carrying out the initial Michael addition reaction, which served as the chain-extension step. Finally, the oligomer was dissolved in EA (half the volume of DCM), followed by the preparation of the polymer film.

Preparation of CLCE films
0.3 wt% Irgacure 819 (excluding solvent mass, 1 mg, 0.002 mmol) was added to the oligomer solution, and then poured into a glass mold at 68 °C. The solvent was evaporated under dark conditions, and a certain self-assembly time was maintained. When the mass of RM82 was 240 mg, a glass mold with dimensions of 50 mm * 30 mm * 10 mm was used. The self-assembly times for SS-CLCE, C-CLCE, and conventional CLCE were 4 h, 8 h, and 4 h, respectively. And C-CLCE underwent an annealing process (heated to 100 °C and then cooled to 68 °C). Finally, irradiate with a 450 nm blue LED (100–260 V, 50 W) for three minutes to carry out the photopolymerization process.

Characterization
1H NMR spectra were recorded on a Bruker AVANCE III HD 400 MHz spectrometer using CDCl3 as solvent. FTIR spectra were measured on a Nicolet 6700 FTIR spectrometer. POM images of CLCEs were characterized by Leica DM2500P polarized optical microscopy operating in transmission mode, coupled with a temperature-controlled hot stage (Linkam THMS-600) calibrated to ±0.1 °C. The temperature-dependent POM images were taken after heating at a rate of 2 °C min−1, followed by a 1-min hold. DSC measurements were performed using a DSC 3500 Sirius (Netzsch) between −30 and 140 °C with heating and cooling rates of 10 °C min−1 under nitrogen. The tension measurement was carried out using a stretching machine F105-EM (Mark-10). XRD measurement was conducted using a Shimadzu XRD-7000 diffractometer with Cu Kα radiation. The reflection spectra are recorded with an Avantes AvaSpec-2048 spectrophotometer in the dark at room temperature. SEM images of the SS-CLCE was obtained using a TESCAN MIRA LMS scanning electron microscope at an acceleration voltage of 3 kV. Film cross sections were prepared by fracturing after freezing in liquid nitrogen. 2D-WAXS measurements were performed using an Anton Paar SAXSpoint 2.0 system equipped with a Cu Kα radiation source (λ = 0.154184 nm, 40 kV) and a 2D hybrid photon-counting detector (EIGER R 1M, pixel size = 75 μm). The sample-to-detector distance was 0.54 m. The in-situ temperature-dependent test was conducted by holding at 30 °C, 46 °C, 53 °C, and 80 °C while collecting data. 2D-SAXS measurements were performed using a Xenocs Xeuss 2.0 system equipped with a Cu Kα radiation source and a 2D hybrid photon-counting detector (platus 3R, pixel size = 172 μm). The sample-to-detector distance was 0.38 m.

One-way shape-color integrated memory
The shape of the mold during polymerization determined the permanent shape of the SS-CLCE. We prepared strip-shaped film using a simple quadrilateral mold. The film was used after being stored at room temperature for 24 h following preparation. Then, it was fully softened by heating on an 80 °C hot stage for 10 s, causing a sharp decrease in stiffness (modulus) to facilitate strain generation. The softened film was then molded into a shelf shape and placed in a 30 °C oven for 24 h to enable efficient physical crosslinking, enhancing stiffness to fix the shelf shape and the structural color induced by deformation. Finally, the SS-CLCE in the shelf shape was demolded.
The shelf-shaped SS-CLCE was heated on an 80 °C hot stage to restore its permanent shape. It was then stretched and coiled around a metal rod to form a spiral structure. After fixing both ends, the film underwent a crosslinking process, and the spiral-shaped SS-CLCE was obtained upon demolding. Notably, benefiting by the intrinsic nature of spontaneous physical crosslinking, the material could be reused multiple times.
A large-area SS-CLCE film was fabricated for more intricate programming. After heating, the film was stretched and spread over a plaster mask mold. A commercial plastic film was first applied to the surface, followed by commercial clay to ensure firm contact. The plastic film was used to prevent clay residue from adhering to the SS-CLCE surface. After placing the setup in a 30 °C oven for 24 h, the demolded SS-CLCE mask retained its shape and structural color.

Encrypted information writing
The film was used after being stored at room temperature for 24 h following preparation. A heating pen set to 80 °C was gently applied to the surface of the SS-CLCE film to write target information (e.g., “2025” or “CLCE”). The written information was more distinguishable under right-handed circular polarizer. The strain was maintained for 24 h to fix the color pattern. Erasure was performed as described in the One-way shape-color integrated memory section. The film was then stored at room temperature for 24 h before the next writing cycle.

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "This manuscript reports a phase transition–enhanced chiral liquid crystal elastomer (CLCE) system and provides a systematic structural characterization alongside mechanistic insights into its behavior. The authors demonstrate both shape memory and mechanochromic color-changing properties, offering potentially valuable applications in smart materials. However, several critical issues must be addressed before the manuscript can be considered for publication:\n1. The novelty of this work requires further clarification and differentiation. There are already existing reports on the incorporation of crystallizable segments into liquid crystal elastomers (LCEs), with well-established mechanisms demonstrating how crystalline domains enhance mechanical properties and shape memory behavior. Importantly, these systems do not require extended programming times, which raises questions about the practical advantages and distinctiveness of the current approach.\n2. The narrative logic of the manuscript, particularly regarding the preparation and classification of CLCE films, lacks clarity. The distinction among the three types of CLCEs, particularly SS-CLCE and C-CLCE, is introduced early in the manuscript, yet the exact conditions referred to as \"optimal duration\" and \"extended duration\" of oligomer self-assembly are not explicitly defined. Moreover, no rationale is provided for how these durations were chosen.\n3. The investigation of aging time (0~72 hours) and temperature (-7~50 °C) effects on mechanical performance indicated that the modulus of SS-CLCE increases to 43 MPa and slowed down after 48 hours of aging. However, the authors also stated that it further increased to 63.4 MPa after two weeks (Figure 17). The manuscript lacks analysis of the specific conditions under which the highest modulus was achieved. When investigating aging time and temperature independently, the authors should also specify the constant value of the other variable to ensure interpretability.\n4. Although the CLCE material is designed to undergo color changes via strain-induced pitch variation in its chiral nematic structure, the apparent color tunability and controllability remain limited compared with the reported CLCEs.\n5. The statement on Page 19, Lines 359–361: “SS-CLCE can fully soften within 10 seconds when heated to 80 °C and remain flexible for the following 8 hours, allowing for large and complex deformations with minimal force”—requires clarification. The manuscript does not discuss what mechanical or structural changes occur if the sample is maintained at 80 °C beyond 8 hours or stay at room temperature. As the authors also declared “Near room temperature, the material undergoes spontaneous phase transitions, forming physical crosslinks that enhance stiffness”. Given the importance of thermal programming and retention in shape memory materials, this point should be further investigated.\n6. The concept of a “4D memory effect” as used in this manuscript is not suitable for the current system. The reported effects are limited to shape memory behavior of a 3D structure and accompanied with color variation triggered by temperature, which does not meet the widely accepted definition of 4D transformation that typically involves time-dependent shape reconfiguration beyond conventional SMP behavior. Color cannot be considered as one dimension.\n7. In Figure 5d, the programming process involving mold shaping at 80 °C for 24 hours is significantly longer than those reported for conventional shape memory LCEs. Similarly, the statement on Page 22, Lines 416–417 (“Subsequently, the self-reinforcement effect helped preserve the displayed information by maintaining external stress at 30 °C for one day”) raises concerns regarding the practicality of the approach.", "reviewer_2": "This work presents a stiffness-switchable chiral liquid crystal elastomer (SS-CLCE) that achieves intrinsic 4D memory of both shape and structural color. By introducing long side chains to induce microphase separation at room temperature, the material autonomously stiffens over time, enabling high-fidelity shape and color retention without external energy input. The system allows full reset via heating, facilitating recyclable and reprogrammable applications such as rewritable encryption layers. This approach transforms traditional material aging into a programmable feature, offering a new design paradigm for multifunctional, energy-efficient smart polymers. In addition, reprogramming via microphase separation is highly innovative in the field of LCEs. Overall, the paper is well-organized and written. The topic and the quality match the requirements of Nature Communications. There are some comments for authors to consider.\n1. What is the relationship between the smectic, nematic, and chiral phases? In typical experiments, specific mesogens (such as C6BAPE) are usually required to obtain smectic-phase LCEs. However, in this work, RM82 alone can induce the smectic phase. What are the conditions for the transition from a (chiral) nematic phase to a (chiral) smectic phase? Can the smectic and nematic phases coexist in LCE?\n2. How is the formation of the smectic phase related to the chemical composition and network structure of the system? Why is phase separation unable to occur in CLCE containing only EDDET?\n3. The text mentions C-CLCE. What is the main difference in the network structure between C-CLCE and SS-CLCE? What is its primary role in the experiment?\n4. Through the aging process, the modulus of the CLCE increases. How much improvement does its work capacity show compared to traditional non-aged CLCE or traditional LCE?\n5. In Fig. 6c, why does the CLCE film appear white under natural light but show bright red under R-CP light? It is expected to see red color under natural light as well.\n6. The formatting should be checked; for example, the font for \"°C\" in the figures is inconsistent with the rest of the text. The scale bar in Figure 6 is not labeled with dimensions.\n7. The following references may be helpful for introducing this work:\nMatter 2025, 8, 101950 (10.1016/j.matt.2024.101950); Adv. Fiber Mater. 2025, 7, 1010-1041 (10.1007/s42765-025-00539-4).", "reviewer_3": "The authors present an impressive and timely study on stiffness-switchable chiral liquid crystal elastomers (SS-CLCEs), demonstrating 4D memory effects and rewritable photonic encryption. The topic is highly significant, and the work offers exciting potential for both fundamental understanding and practical applications. While I greatly appreciate the novelty and experimental effort invested in this work, several aspects would benefit from further clarification, additional evidence, and expanded discussion. Overall, this manuscript addresses an important challenge in stretchable photonic materials and presents novel findings on stiffness-switchable CLCEs. I commend the authors for their innovative work. Nevertheless, clarification of the synthesis mechanism, quantitative analysis of phase coexistence, improved imaging, and discussion of durability and practical considerations are essential to strengthen the impact of the study. Addressing the points in below would significantly enhance the clarity, rigor, and overall contribution of the manuscript."}, "author_response": "Point-by-point response to the reviewers’ comments\nRevised title: Buprestidae Metamorphosis-Inspired Stiffening Photonic\nElastomers for Shape-Color Integrated Memory and Information Encryption\nManuscript ID: NCOMMS-25-60167\nType: Article\nWe greatly thank the respected reviewers and appreciate the time they spent providing\nvaluable comments concerning our manuscript. We have seriously considered all the\ncomments of three reviewers and revised our manuscript according to their helpful\nsuggestions. A detailed point-by-point response is provided below. We have implemented\nextensive changes that are highlighted yellow in the revised manuscript and revised\nsupplementary information. We believe that the quality of the revised manuscript has been\ngreatly improved.\n(Reviewers’ comments: black italic font; our responses to the comments: in blue; what we\nrewrote in the revised manuscript: in blue and underlined.)\nReviewer #1 (Remarks to the Author):\nThis manuscript reports a phase transition–enhanced chiral liquid crystal elastomer\n(CLCE) system and provides a systematic structural characterization alongside\nmechanistic insights into its behavior. The authors demonstrate both shape memory and\nmechanochromic color-changing properties, offering potentially valuable applications in\nsmart materials. However, several critical issues must be addressed before the manuscript\ncan be considered for publication.\nOur response:\nWe sincerely appreciate the reviewer’s insightful evaluation of our work. The reviewer’s\n\nthorough comments and constructive suggestions hold significant guiding value for the\nimprovement of our manuscript. We believe that the quality of the carefully-revised\nmanuscript has been enhanced after addressing those critical issues. Our detailed point-by-\npoint responses are provided below.\n1) The novelty of this work requires further clarification and differentiation. There are\nalready existing reports on the incorporation of crystallizable segments into liquid crystal\nelastomers (LCEs), with well-established mechanisms demonstrating how crystalline\ndomains enhance mechanical properties and shape memory behavior. Importantly, these\nsystems do not require extended programming times, which raises questions about the\npractical advantages and distinctiveness of the current approach.\nOur response:\nThank you very much for your thoughtful comment on the novelty of our work. We greatly\nappreciate your professional insight in pointing out the existence of similar prior studies\nand fully recognize the importance of distinguishing our work from existing studies.\nIn brief, the innovative points of our work can be summarized as follows:\n(1) The combination of shape memory and structural color, as well as subsequent\napplications.\n(2) Construction of low-crosslinking, side-chain-containing covalent network.\n(3) Mechanical enhancement induced by microphase separation in a single-component\nliquid crystal (LC) material system.\n(4) The crystallization of polymer chains (also considered a type of phase transition) and\nLC phase transitions within the N* host, which together result in microphase separation.\n(5) A simple and feasible method for preparing stiffened CLCE. (This point will be jointly\nexplained alongside the valuable Suggestion 2.)\nFirstly, we would like to note that the most direct distinction lies in the application focus\nof previous studies, which mainly aimed at shape memory and actuation performance. In\ncontrast, our work achieves material colorization, as well as thermal writing and erasing of\ninformation, based on the shape memory effect. While colorization is a fundamental\ncharacteristic of CLCEs, realizing the integration of those features is challenging.\nNext, we are trying to clarify the underlying novelty, regarding the first point—the\ninnovation of the mechanical-enhancement mechanism.\nThe mechanisms of mechanical enhancement may appear similar, our approach differs\nsubstantially in the details. We acknowledge that the effect of crystallization on mechanical\nstrengthening is well-established in LCE system, but what we want to emphasize is our\neffort to construct the microphase-separation-enabled covalent network in CLCEs. It’s\nabout not only crystalline but also accompanying smectic arrangement.\nIn previous studies, it is demonstrated that introducing crystallizable segments leads to the\nintroduction of crystallinity, thereby achieving toughening and enhancement in achiral\nLCEs. (See Ref. 35. Macromolecules, 2021, 54, 8987-8995. Ref. 37. Small, 2025, 21,\n2406493.) We appreciate these works and have drawn on them. However, the mechanism\nthat is feasible in LCE does not exhibit a significant effect when applied alone in CLCEs.\nThat is to say, merely introducing the crystallizable segments into the CLCEs does not lead\nto a significant mechanical enhancement (Take an aging time of 24 hours as an example).\nWhen we used ODT as the chain extender with a molar ratio of RM82 (240 mg, 0.357\nmmol) to ODT (57.1 mg, 0.321 mmol, 18.1 wt%) of 1:0.9 (a common ratio for CLCE\npreparation), the resulting CLCEs did not exhibit time-dependent mechanical\nreinforcement compared to those prepared via the same method described in the Methods\nsection. In this case, although the content of crystallizable segments was sufficient, the\nexcessive acrylate groups reacted with all thiol groups. The formed long oligomer chains\nunderwent terminal crosslinking upon photoinitiation, theoretically yielding fully\ncrosslinked main-chain CLCEs. Despite having a tendency to crystallize, the helical\nstructure and crosslinked network—even with a relatively low crosslinking degree—\nrestricted the mobility of molecular chains. Consequently, the CLCEs could not achieve a\nhigh crystallinity as easily as achiral LCEs. This is evidenced by the stress-strain curves of\nthe sample both before and after aging (Figure R1a). However, through the strategy\nelaborated in this manuscript, the SS-CLCE sample with a crystallizable segment content\nof 16.2 wt% exhibits more significant mechanical reinforcement than the sample with a\nhigher crystallizable component content of 18.1 wt% (where only the content of\ncrystallizable components was emphasized) (Figure R1b).\nFigure R1. (a) Strain-stress curves of the CLCE sample after 24 hours of aging (the stepped\ncurve is attributed to the 0.02 N precision of the tensile equipment). (b) Strain-stress curves\nof the SS-CLCE sample after 24 hours of aging.\nBased on the above experimental results, we point out that in the preparation of\nstiffened CLCEs, it is necessary not only to introduce crystallizable segments but also\nto construct a covalent network environment that facilitates segmental motion—thus\nhighlighting the presence of the side-chain oligomers we emphasized (Figure R2\n(Supplementary Fig. 2)).\nFigure R2. Polymer construction strategies and characterization. (Supplementary Fig. 2)\nIn the NMR spectrum of the oligomer, both acrylate and thiol groups remain before\nphotopolymerization. However, the post-photopolymerization FTIR spectrum indicates the\ndisappearance of acrylate groups and the persistence of thiol groups. The residual thiol\ngroups are located at the terminal ends of the side chains, while the other ends of the side\nchains are covalently attached to the main chain. The presence of these side chains\nfacilitates the ordered arrangement of alkyl chains and, more importantly, enables\nLC mesogens to undergo phase transitions more easily.\nThe resulting CLCEs can intrinsically undergo not only crystallization but also LC phase\ntransitions. According to our research, the change in the order degree of long methylene\nchains and the structural change of the smectic sequence promote each other. The presence\nof polymer crystals induces the layered arrangement of LC mesogens directly linked to\nalkyl chains, and the layered arrangement of LC mesogens, in turn, promotes the extension\nof polymer crystals. The coexistence of the two exerts a more significant microphase\nseparation-induced toughening and strengthening effect (Figure R3).\nFigure R3. Mechanical enhancement brought about by complex phase transitions. (a) Rich\nphase transformation processes and (b) mechanical strengthening effects of SS-CLCE. (Fig.\n2)\nTo clarify, we have revised the manuscript as follows:\n\"Recently, it has been confirmed that introducing crystallizable chains in nematic LCEs\ninduce some crystallinity ... However, in chiral environments like chiral LCEs (CLCEs)—\npolymer-based photonic crystals with periodic structures and distinctive structural colors—\nthe arrangement of LC units exhibits various ordering patterns, such as a helical structure\n(Fig. 1b, Bottom), which causes the arrangement of the crystallizable segments attached to\nboth ends of the rod-like LC cores to deviate from the ordered arrangement of\ncrystallization. And the crosslinked network of the elastomer restricts molecular chain\nmotion, making the formation of crystalline (Cr) regions and the subsequent significant\nmechanical strengthening difficult in CLCEs, even if sufficient crystallizable components\nare introduced. \" (Highlighted in Introduction, page 3, lines 54-63)\n\"We achieve the formation of side chains with greater mobility by controlling the\nfunctional group relationships during the synthesis process to induce the main chains in a\nlow-crosslink-density polymer network to participate in the transition from the chiral\nnematic (N*) phase to the partly-formed smectic C (SmC) phase and the formation of\ncrystalline phase of polymer chains.\" (Highlighted in Introduction, page 4, lines 78-81)\nFinally, we are trying to clarify the programming-time problems, regarding of the second\npoint of the suggestion. As discussed above, the helical structure of the CLCE makes the\nrearrangement of crystallizable chains relatively difficult, while mechanical reinforcement\nis achieved through side-chain-induced extensive microphase separation. Therefore, the\nmechanism is not exactly the same, and the time-dependent behavior should also be\ninterpreted with consideration of the structural differences between CLCEs and LCEs.\nHere is the comparison of programming times with previous work. In previous works,\nWare et al. (Macromolecules 2017, 50, 4267−4275) reported a crystallized LCE requiring\n\"at least 12 hours\" of aging time at room temperature, attributed to the extremely low-\ncrosslinking network with an approximate elongation at break of 500%. Norikane et al.\n(Macromolecules 2021, 54, 8987–8995) reported that the introduction of long methylene\nchains into LCEs exerts a positive effect on crystallization, and specified the aging\ncondition of 24 h at 20 °C. Kim et al. (Small 2025, 21 ,2406493) reported that the\nintroduction of crystallizable segments into LCEs exerts a strengthening effect on the\nmaterials, and specified the aging condition as \"samples then stored overnight to be\ncrystallized\". Ji et al. (Nature Communications 2024, 15, 9902) incorporated crystallized\nLCEs into the LCE matrix to form a semi-interpenetrating network, and the article states\nthe following: \"The results indicated that their crystallization behaviors were observed after\n1 day, and the crystallization process could be mostly completed in 5 days.\" We are indeed\naware of the versatility brought by the introduction of crystallization into LCEs, and we\nhave also noted that crystallized LCEs have found applications in various fields. We aim\nto incorporate phase transitions such as crystallization into CLCEs to enrich the material's\nfunctionality; however, the issue of relatively long programming time does exist.\nAccording to our research, the hardening process of CLCEs is lengthy, but the rate is fastest\naround 18 hours at room temperature (then the rate of hardening gradually decreased)—\nand this is one of the reasons we chose 24 hours as the programming condition (Figure R4).\nThis duration is indeed longer compared to that of conventional crystalline polymers, but\nfor LCE, it is not that bad.\nFigure R4. The variation trend of Young's modulus with aging time. (Fig. 4c)\nThanks to the reviewers' suggestions, we have realized the significance of shortening the\naging time. Therefore, we have adopted corresponding measures to minimize the\nprogramming time (including increasing the content of crystallizable segments and\nraising the programming temperature). These will be jointly explained alongside the\nvaluable Suggestion 7.\n2) The narrative logic of the manuscript, particularly regarding the preparation and\nclassification of CLCE films, lacks clarity. The distinction among the three types of CLCEs,\nparticularly SS-CLCE and C-CLCE, is introduced early in the manuscript, yet the exact\nconditions referred to as \"optimal duration\" and \"extended duration\" of oligomer self-\nassembly are not explicitly defined. Moreover, no rationale is provided for how these\ndurations were chosen.\nOur response:\nWe are grateful to the reviewer for the careful suggestion on the narrative logic of our work.\nWe apologize for the insufficient introduction and lack of differentiation of the material in\nthe earlier part of Results, and we would explain these details and revise the manuscript\naccordingly.\nThe distinction among the three types of CLCEs and their roles in this paper are as follows:\n(1) Traditional CLCE is used to briefly illustrate the basic characteristics of non-crystalline,\nnon-phase-separated film.\n(2) SS-CLCE is the core material of this study, featuring microphase-separation-induced\nreinforcement.\n(3) C-CLCE is the representative control sample identified during the exploration of\nsuitable preparation methods for SS-CLCE, used to verify the rationality of parameter\n(temperature, time) selection in the SS-CLCE preparation process, also featuring\nmicrophase-separation-induced reinforcement.\nAs stated in the Methods section of the manuscript: \"The self-assembly times for SS-CLCE,\nC-CLCE, and conventional CLCE were 4 h, 8 h, and 4 h, respectively\"—this implies the\nselection of duration, yet we recognize that clarity is lacking. The selection of duration is\nrelated to the evaporation of ethyl acetate solvent and the self-assembly degree of\noligomers. Figure R5 shows the photographs of the oligomer solution at different durations\nafter it is poured into the glass mold.\nFigure R5. The appearance of the samples at different durations. (Supplementary Fig. 3)\nAfter 1 hour, most of the ethyl acetate had evaporated, and the LC oligomers existed in a\nmulti-domain state with a uniform and defect-free surface. After 4 hours, the ethyl acetate\nhad completely evaporated. The film exhibited weak red reflection, and circular defects\n(small black spots) formed by oligomer crystallization began to appear on its surface. As\ntime extended, the crystalline regions increased in number and size, forming a large number\nof circular defects. It would damage the LC phase and impair the tensile properties of the\nCLCE after polymerization. If sufficient time (overnight) was allowed before\npolymerization, the entire film would be covered by the crystalline region, and the resulting\npolymer had extremely poor toughness. It is noted that the high temperature required to\nkeep the oligomers from crystallizing for a long period is above the isotropic phase\ntransition point. Therefore, our strategy is to carry out polymerization at a moderate\ntemperature (68 °C) for an \"optimal duration\" (4 h), when no macroscopic crystalline\nregions have appeared in the oligomers. The CLCE obtained in this way inherently exhibits\na tendency for crystallization in the initial arrangement of its molecular chains (if\npolymerization is not performed, macroscopic visible crystallization of the oligomers will\nsoon occur at that time). Since the film directly polymerized after \"extended duration\" (8\nh or more) were nonuniform and mechanically weak, and thus could not be defined as\nelastomers, the precursor was rapidly heated to the isotropic state (100 °C) and\nsubsequently cooled to 68 °C for polymerization. The resulting C-CLCE possessed\ncomparable toughness and microphase-separation-induced reinforcement. However, due\nto the absence of alignment force, no structural color was observed.\nTo clarify, we have included the photographs of oligomers at different durations (Figure\nR5 as Supplementary Fig. 3) in the revised Supplementary Information. We also have\nrevised the manuscript as follows:\n\"EDDET was used as the chain extender for conventional CLCEs, while ODT was\nprimarily used as the chain extender for SS-CLCEs. After the completion of chain\nextension, the obtained oligomers were dissolved in EA, poured into molds, and the solvent\nevaporation and self-assembly processes were then initiated. In this study, three types of\nCLCE films were prepared under different conditions. The films primarily extended with\nODT were categorized by oligomer self-assembly duration before photopolymerization:\nSS-CLCE (optimal duration) and controlled CLCE (C-CLCE) (extended duration). The\nfilm exclusively using EDDET as the chain extender was designated as conventional CLCE.\nAccording to our strategy, most of the acrylate and thiol groups underwent addition\nreactions in the first chain-extended step, as confirmed by 1H NMR spectrum.\"\n(Highlighted in Results, page 6, lines 107-116)\n\"Due to the long linear structure and crystallizable segment-containing characteristic of\nSS-CLCE oligomers, gradual self-assembly occurred during the evaporation film-forming\nprocess, leading to the formation of large-sized spherulites—which was detrimental to the\nintegrity of the polymer film (Supplementary Fig. 3). Therefore, this gave rise to the\ndiscussion on the selection of appropriate self-assembly conditions. When ODT was used\nas the primary chain extender, intriguing phenomena emerged. We selected 4 hours (a\nduration with no macroscopic defects observed) as the self-assembly time prior to\npolymerization, the resulting SS-CLCE presented white, and showed a controlled rigidity\nthat disappeared upon heating.\" (Highlighted in Results, page 7, lines 139-146)\n\"When the self-assembly time was further extended to 8 h or more, the influence of the\nauxiliary phase on the primary N* phase became significant, a large number of\nmacroscopic defects (crystalline regions) are generated, which seriously affect the\nuniformity of the film. To prepare uniform elastomer films, a heating (100 °C) and cooling\n(68 °C) process was applied to eliminate crystalline regions. The resulted CLCE was\ndefined as the controlled CLCE (C-CLCE), which was induced into a vertical alignment\nmode due to the absence of orientation effect induced by evaporation.\" (Highlighted in\nResults, page 8, lines 158-164)\n\"The self-assembly times for SS-CLCE, C-CLCE, and conventional CLCE were 4 h, 8 h,\nand 4 h, respectively. And C-CLCE underwent an annealing process (heated to 100 °C and\nthen cooled to 68 °C).\" (Highlighted in Methods, page 28, lines 556-558)\n3) The investigation of aging time (0~72 hours) and temperature (-7~50 °C) effects on\nmechanical performance indicated that the modulus of SS-CLCE increases to 43 MPa and\nslowed down after 48 hours of aging. However, the authors also stated that it further\nincreased to 63.4 MPa after two weeks (Figure 17). The manuscript lacks analysis of the\nspecific conditions under which the highest modulus was achieved. When investigating\naging time and temperature independently, the authors should also specify the constant\nvalue of the other variable to ensure interpretability.\nOur response:\nWe thank the reviewer for the valuable suggestion. We apologize for the insufficient\ndescription of variables. We would like to explain that when studying time dependence,\nwe specified in the caption of Fig. 4c that the temperature was fixed at 20 °C. When\nstudying temperature dependence, we provided the description \"... with a fixed aging\nduration of 24 hours\" in the manuscript. And all the stretching rates mentioned above are\nset at 25 mm min-1.\nTo clarify the interpretability, we have added a cyclic test of heating the film at 80 °C\nfor 1 minute and holding it at 20 °C and 40 °C for 24 hours, so as to illustrate the\nfilm's stability, durability, and the certainty of spontaneous microphase separation\nthrough the stress magnitude under 100% strain (Figure R6).\nFigure R6. Heating-aging cycle test and the reflection spectra after the cycles. (a, b)\nMechanical properties after heating and aging: the first 10 cycles are the results of aging at\n20 °C, and cycles 11 to 20 are the results of aging at 40 °C. (c) The reflection spectra before\nand after the cycles indicate no significant change in structural color and (d) their\nphotographs. (Supplementary Fig. 23)\nFigure R6 indicates that the film exhibits excellent cyclic performance and durability, with\nreliable temperature and time dependence, and the cycles do not impair the structural color\ncharacteristics of the film.\nTo clarify, we have added Figure R6 as Supplementary Fig. 23, we also have revised the\nmanuscript as follows:\n\"To investigate the time-dependent self-reinforcement effect, the tensile properties were\ntested for aging times ranging from 0 to 72 hours, with the treatment temperature fixed at\n20 °C (the second variable affecting the aging degree) to ensure a uniform aging rate. The\nstretching rate was fixed at 25 mm min-1.\" (Highlighted in Results, page 18, lines 346-350)\n\"f Stress-strain curves for the 0-100% strain range after aging at different temperatures at\na fixed time of 24 h. The dashed arrows reflect the effect of increasing aging temperature\non the self-reinforcement effect.\" (Highlighted in caption of Fig. 4f, page 17)\n\"To further investigate the temperature-dependent self-reinforcement effect, the tensile\nproperties of SS-CLCE films were tested at different temperatures with a fixed aging\nduration of 24 hours to exploring the impact of temperature on the rate of aging. The\nstretching rate was fixed at 25 mm min-1.\" (Highlighted in Results, page 20, lines 388-391)\n\"At an optimal temperature, self-enhancement of mechanical properties can be achieved\nwithin a short time, whereas excessively low or high temperatures prolong or even prevent\nphase separation from occurring (Fig. 4g, bottom). Heated-aged cycle tests were conducted\nto demonstrate the stability of the self-reinforcement effect and the durability of the SS-\nCLCE. The mechanical properties after aging at different temperatures and the structural\ncolor after cycling both indicated the durability and fatigue resistance (Supplementary Fig.\n23).\" (Highlighted in Results, page 20, lines 407-412)\nRegarding the specific conditions for achieving the highest modulus, we explain that a\nprolonged period is required to undergo \"complete\" hardening for SS-CLCE at 20 °C (a\ntemperature close to the conventional temperature in daily life). According to our research\n(Figure R4), the aging rate of SS-CLCE exhibited an obvious S-shaped curve, and the\nhighest rate occurred between 12 and 24 hours, among which the average aging rate\nbetween 12 and 24 hours is 2.11 MPa h-1. During this process, the material had transformed\nfrom a soft film that deforms easily into a tough film with a certain ability to resist\nstretching. Subsequently, the rate gradually decreases, as exemplified by the minimum\nrate we recorded of 0.07 MPa h-1 (between 48 and 336 hours). We also have kept a\nsample until today at room temperature (more than 5 months or 3600 hours), and\ntested its tensile property, and compare it with several key points (Figure R7).\nSamples stored at room temperature for 3600 h (5 months) exhibited the same Young's\nmodulus as those stored for 336 h (two weeks), while the yield strength showed a slight\nincrease. We acknowledge that it is difficult to specify the exact time required to achieve\nthe optimal mechanical properties (at 20 °C). However, we have already stated in the initial\ndraft and continue to clarify here that the focus of this study lies on the time periods with\na relatively fast enhancement rate—such as the Young's modulus of 33.1 MPa at 24 h or\n43.1 MPa at 48 h. It is unnecessary to extend durations to periods with extremely low\nenhancement efficiency. The reason we present the mechanical properties at longer time\nintervals (336 h or 3600 h) is to demonstrate the permanent positive effect of spontaneous\nphase separation on the material, which aligns with the statement in our paper: \"As time\nprogressed, the mechanical properties continuously improved, making aging an advantage\nrather than a failure process.\" However, based on the valuable suggestions provided by the\nreviewer, we employed several methods to significantly increase the enhancement rate, so\nas to achieve a higher modulus in a shorter period of time. These will be jointly explained\nalongside the valuable Suggestion 7.\nFigure R7. The differences in mechanical properties at different duration scales.\n(Supplementary Fig. 21a)\nTo clarify, we have included the stress-strain curve under a longer duration (Replace\nSupplementary Fig. 21a with Figure R7) in the revised Supplementary Information. We\nalso have revised the manuscript as follows:\n\"To examine the mechanical performance potential of SS-CLCE, we set the aging time to\ntwo weeks and even five months for testing (Supplementary Fig. 21). The stress-strain\ncurves indicated that after 2 weeks of aging, the Young's modulus increased from 43.1 MPa\n(at 48 h) to 63.4 MPa. However, no significant increase in Young's modulus was observed\nfor the material aged for 5 months, with only a partial improvement in toughness. This\nphenomenon demonstrated that the SS-CLCE film still underwent a self-reinforcement\nprocess after 2 weeks. Nevertheless, after 48 hours, the material required much more time\n(tenfold to hundredfold) to achieve a much smaller enhancement. The result was consistent\nwith the S-shaped enhancement trend. Guided by the principle of efficiency, we selected\n24 hours or 48 hours as the main research timeframes.\" (Highlighted in Results, page 19,\nlines 367-376)\n\"Stress-strain curve for strains ranging from 0 to 100% of SS-CLCE film aged for\nrepresentative durations. The film after 5 months showed no significant increase in elastic\nmodulus, and the time scale is too long. Thus, this data is only used to imply the continuous\nimprovement effect of aging on mechanical properties.\" (Highlighted in the caption of\nSupplementary Fig. 21)\n4) Although the CLCE material is designed to undergo color changes via strain-induced\npitch variation in its chiral nematic structure, the apparent color tunability and\ncontrollability remain limited compared with the reported CLCEs.\nOur response:\nWe thank the reviewer for this important comment. We acknowledge that the structural\ncolor of SS-CLCE does have limited color contrast compared to many previously reported\nCLCEs. Here, we would like to explain that there are multiple factors contributing to the\nrelatively light (fair) color.\nFirst, the synthesis ratio of LC oligomers has a significant impact on color rendering. In\nthis work, to prepare oligomers and form a small amount of side chains with remaining\nthiol end-capping after polymerization, we adopted an extreme molar ratio of acrylate\ngroups to thiol groups of 1:0.99. This ratio leads to the continuous progress of the chain\nextension addition reaction, tending to form longer linear chains. However, longer linear\nchains are not a positive factor for N* phase self-assembly. This factor has been elaborated\nin the work of Li et al. (Advanced Functional Materials. 2025, 35, 2413965) When the ratio\nof acrylate to thiol is close to 1:1, the structural color will be of medium quality.\nSecond, the microphase separation strategy we employed also exerts an influence on the\npresentation of structural color. As we explained in our response to Suggestion 2, the\noligomer undergoes spontaneous arrangement of long chains before polymerization,\nthereby gradually forming large-scale crystalline regions. Although we chose to carry out\nthe polymerization process before the formation of the crystalline region, the arrangement\nprocess obviously has a negative impact on the uniform vertical alignment of the N*\nhelical structure.\nThird, it is the for choosing the solvent evaporation method. The solvent evaporation\nmethod is a simple approach for preparing LCEs. It enables the vertical alignment of the\nhelical axes of CLCEs through the orientation force generated by solvent evaporation.\nHowever, due to the long spacing and high viscosity of the LC oligomers, this method can\nonly achieve limited effectiveness. Nevertheless, it is convenient and feasible, eliminating\nthe need for LC cell preparation and the corresponding manufacturing processes, as well\nas reducing restrictions on molds, thereby facilitating the preparation of large-area thin\nfilms. Additionally, although the strong anchoring effect of the alignment layer in the LC\ncell is sufficient to induce nearly perfect alignment of the oligomers, the lack of a swollen\nnetwork and the constraints on the movement of polymer chains are unfavorable for the\nsubsequent occurrence of phase separation.\nIn summary, there are multiple factors contributing to the limitations of structural color.\nHowever, we still take pride in the goal we have achieved—realizing stiffness switching\nof single-layer free-standing chiral liquid crystal elastomer (CLCE) films via a simple\nmethod. Currently, in the CLCE system, there are relatively few references regarding this\ntarget, which indicates greater room for improvement, both in terms of color and the degree\nof stiffness enhancement.\nAs a signature characteristic of CLCEs, their structural color indeed requires\nadditional attention. On the premise of maintaining the original mechanical\nproperties, stiffness switching performance, and phase separation strategy\nunchanged, we have updated the physical display image (Fig. 5c) to improve the image\nquality as much as possible.\nTo clarify the limitations of structural color, we have revised the manuscript as follows:\n\"Overall, the color change in the film was uniform, demonstrating its soft-elastic behavior.\nIt should also be noted that the structural color exhibited by SS-CLCEs has certain\nlimitations compared with existing CLCEs, which is attributed to the molar ratio of acrylate\nto thiol (used for oligomer preparation) being close to 1:1, as well as the selection of the\nmicrophase separation strategy and the solvent evaporation method. The trade-off involved\ncauses SS-CLCEs to sacrifice the quality of structural color in exchange for switchable\nmechanical properties.63\" (Highlighted in Results, page 16, lines 316-321)\n\"63 Li, S. et al. Direct Ink Writing of Cephalopod Skin-Like Core-Shell Fibers From\nCholesteric Liquid Crystal Elastomers and Dyed Solutions. Adv. Funct. Mater. 35,\n2413965 (2025). \"\nFigure R8. Demonstration of stiffness switching and shape-color integrated programming\n(Fig. 5)\n5) The statement on Page 19, Lines 359–361: “SS-CLCE can fully soften within 10 seconds\nwhen heated to 80 °C and remain flexible for the following 8 hours, allowing for large and\ncomplex deformations with minimal force”—requires clarification. The manuscript does\nnot discuss what mechanical or structural changes occur if the sample is maintained at\n80 °C beyond 8 hours or stay at room temperature. As the authors also declared “Near\nroom temperature, the material undergoes spontaneous phase transitions, forming\nphysical crosslinks that enhance stiffness”. Given the importance of thermal programming\nand retention in shape memory materials, this point should be further investigated.\nOur response:\nWe thank the reviewer for this valuable comment. There may be a misunderstanding\narising from insufficient clarity in our expression. Based on the DSC curves of SS-CLCEs\n(Figure R3), we can observe that both the isotropic phase transition temperature of\nthe smectic phase and the melting range of polymer crystallization are below 80 °C.\nTherefore, we selected 80 °C to eliminate these phase separations, thereby achieving\nthe effect of softening the material. Next, the SS-CLCE was placed at a low\ntemperature (room temperature) to undergo the spontaneous phase separation for\nreinforcement and toughening. Regarding the mentioned 8 hours, this duration was also\nselected based on the modulus-time curve during the material's self-reinforcement process\n(Figure R4). The S-shaped curve exhibits a slow-fast-slow reinforcement rate. Before 8\nhours, the reinforcement rate is slow and the effect is not significant (2.22 MPa to 6.54\nMPa); therefore, we state that the material remains soft and highly deformable within 8\nhours.\nAfter the SS-CLCE is heated and softened at a high temperature of 80 °C to eliminate phase\nseparation, it becomes soft; subsequently, under conditions below the crystal melting point\n(60 °C), it will spontaneously undergo a transition from a disordered phase to an ordered\nphase, thereby achieving self-reinforcement. We selected a number of different\ntemperatures for this process (Figure R9). The stress-strain curves after 24 hours of storage\nat -7~50 °C show that the mechanical reinforcement effect is weak when the temperature\nis close to T and T , while the mechanical strength is enhanced more significantly at\ng m\nsuitable temperatures (20~40 °C). This is related to the segmental motion ability and the\nformation conditions of the ordered phase.\nFigure R9. Stress-strain curves for the 0-100% strain range after aging at different\ntemperatures at a fixed time of 24 h. (Fig. 4f)\nTherefore, the question mentioned in the suggestion—\"what mechanical or structural\nchanges occur if the sample is maintained at room temperature beyond 8 hours\"—is exactly\nthe main research content mentioned in our paper. At this suitable temperature, the polymer\nchains undergo spontaneous ordered arrangement, including smectic formation and\npolymer crystallization. The results are the gradual enhancement of mechanical properties\nand the formation of ordered phases. The second question mentioned in the suggestion—\n\"what mechanical or structural changes occur if the sample is maintained at 80 °C beyond\n8 hours\"—can be inferred that there were almost no changes in structure and mechanical\nproperties, because the temperature exceeded the phase transition temperature. And the\nstress-strain curves and POM images can prove that (Figure R10).\nFigure R10. The result of aging at 80°C for 24 h. (a) There is no obvious enhancement in\nmechanical properties after aging at 80 °C. (Supplementary Fig. 22) (b) The POM images\nshow no significant structural changes.\nTo clarify, we have included the result of aging at 80°C for 24 h in Supplementary\nInformation. (Figure R10a as Supplementary Fig. 22) in the revised Supplementary\nInformation, we have also revised the manuscript as follows:\n\"Specifically, SS-CLCE can fully soften within 10 seconds when heated to 80 °C and\nremain flexible for the following 8 hours at room temperature, attributed to the slow\nreinforcement rate in the initial stage of the S-shaped reinforcement process. The modulus\nremains relatively low within 8 hours, allowing for large and complex deformations with\nminimal force. Certainly, the 8-hour duration is merely a reasonable choice based on the\nreinforcement rate, it is not fixed and can be flexibly adjusted according to specific\nrequirements.\" (Highlighted in Results, page 21, lines 417-423)\n\"When the temperature reached 30 to 40 °C, near the melting range, the mechanical\nperformance peaked. When the temperature increased beyond the early stage of the melting\nrange (50 °C and 80 °C), the mechanical reinforcement weakened. This phenomenon\nreflected that high temperature would also inhibit the occurrence of phase separation,\nfurther underscoring the importance of selecting an appropriate temperature for phase\nseparation. However, at 50 °C, which exceeds the early stage of the melting range, the\nmechanical performance unexpectedly declined, indicating a decrease in crystallinity.\"\n(Highlighted in Results, page 20, lines 395-401)\n6) The concept of a “4D memory effect” as used in this manuscript is not suitable for the\ncurrent system. The reported effects are limited to shape memory behavior of a 3D\nstructure and accompanied with color variation triggered by temperature, which does not\nmeet the widely accepted definition of 4D transformation that typically involves time-\ndependent shape reconfiguration beyond conventional SMP behavior. Color cannot be\nconsidered as one dimension.\nOur response:\nWe appreciate this important suggestion. We recognize that the 4D concept has been well-\nestablished, and the 4D described in this paper is inconsistent with the conventional context.\nTherefore, we would make revisions accordingly. All descriptions of \"4D memory\" in the\nmanuscript (including figures) have been revised to \"shape-color integrated memory \".\nGiven the large number of such revisions, it is not convenient to list them all. All the revised\nparts have been highlighted in the manuscript.\nImportantly, the title has been revised to \"Buprestidae Metamorphosis-Inspired Stiffening\nPhotonic Elastomers for Shape-Color Integrated Memory and Information Encryption\".\n7) In Figure 5d, the programming process involving mold shaping at 80 °C for 24 hours is\nsignificantly longer than those reported for conventional shape memory LCEs. Similarly,\nthe statement on Page 22, Lines 416–417 (“Subsequently, the self-reinforcement effect\nhelped preserve the displayed information by maintaining external stress at 30 °C for one\nday”) raises concerns regarding the practicality of the approach.\nOur response:\nWe thank the reviewer for this constructive comment. The \"programming\" described in our\nwork is based on spontaneous microphase separation to enhance mechanical properties,\nthereby enabling the memorization of various shapes (including curved surfaces, bends,\nand fine textures). In contrast, programming in LCEs (about 10 min) generally refers to\nmolecular orientation induced by stretching and heating, without enhancement of\nmechanical properties. This type of programming is typically used to endow strip-shaped\nfilms with deformability for subsequent actuation. The two concepts differ in their\ndefinitions, resulting outcomes, and application scenarios. In the latter part of our response\nto Suggestion 1, we have provided some explanations and compared with the reported\naging (crystallization) durations of LCE materials (more than 12 h). The condition of \"at\n30 °C for one day\" was a reasonable choice made by us based on the enhancement rate.\nWhen investigating the condition of 20 °C, we have clarified the law of the S-shaped\nenhancement curve (Figure R4) and selected a duration of 24 h (covering the period with\nthe fastest rate). When studying temperature dependence, we identified the optimal\ntemperature range of 30 °C to 40 °C.\nMeanwhile, this insightful comment has made us realize the importance of shortening\nthe duration. By controlling the synthesis process and increasing the programming\ntemperature, we are committed to reducing the programming time as much as\npossible. The method is based on the temperature dependence discovered in our\nexperiments combined with the crystallizable segments emphasized in previous work\n(Figure 4f). We chose to use ODT as the sole chain extender (increased from a ratio\nof 4:1 to 1:0), and the aging temperature of the prepared SS-CLCE films was set at\n40 °C for the time-dependent tests (Figure R11).\nFigure R11. The result of the time-dependent test of SS-CLCE (the ratio of ODT to EDDET\nis 1:0). Stress-strain curves for strains ranging from 0 to 100% at different aging times at\n40 °C. (Supplementary Fig. 24)\nAfter adjusting the ratio and aging temperature, we observed a faster aging rate, with the\nmaximum rate occurring between 2 and 6 hours. At this point, 8 hours can be used as the\nprogramming duration, representing a significant improvement compared to the previous\ncondition. However, all data in the initial manuscript of this work were obtained from SS-\nCLCEs prepared with a molar ratio of ODT:EDDET = 4:1. This ratio can better illustrate\nour viewpoint—i.e., the promoting effect of side-chain functionalization rather than merely\nthe introduction of crystallizable segments. Therefore, we hope to retain the main data in\nthe main text and present the aforementioned experiments as supplementary information\nto provide a method for improving material performance.\nTo clarify, we have added Figure R11 as Supplementary Fig. 24, we have we have also\nrevised the manuscript as follows:\n\"Upon heating, it was also capable of reverting to its original state, thereby enabling the\nnext usage cycle. It is worth noting that the aforementioned programming time requires\nmore than 24 hours to achieve better memory effect. By introducing more crystallizable\nsegments and increasing the aging temperature to accelerate chain rearrangement, the\nduration can be further shortened to 8 hours (Supplementary Fig. 24).\" (Highlighted in\nResults, page 24, lines 462-466)\nReviewer #2 (Remarks to the Author):\nThis work presents a stiffness-switchable chiral liquid crystal elastomer (SS-CLCE) that\nachieves intrinsic 4D memory of both shape and structural color. By introducing long side\nchains to induce microphase separation at room temperature, the material autonomously\nstiffens over time, enabling high-fidelity shape and color retention without external energy\ninput. The system allows full reset via heating, facilitating recyclable and reprogrammable\napplications such as rewritable encryption layers. This approach transforms traditional\nmaterial aging into a programmable feature, offering a new design paradigm for\nmultifunctional, energy-efficient smart polymers. In addition, reprogramming via\nmicrophase separation is highly innovative in the field of LCEs. Overall, the paper is well-\norganized and written. The topic and the quality match the requirements of Nature\nCommunications. There are some comments for authors to consider.\nOur response:\nWe sincerely appreciate the reviewer's positive and encouraging evaluation of this work.\nThese comments and suggestions have actively helped us improve the quality of the\nmanuscript. We have addressed all points raised from the reviewer and revised the\nmanuscript where necessary. Please see our detailed response below.\n1) What is the relationship between the smectic, nematic, and chiral phases? In typical\nexperiments, specific mesogens (such as C6BAPE) are usually required to obtain smectic-\nphase LCEs. However, in this work, RM82 alone can induce the smectic phase. What are\nthe conditions for the transition from a (chiral) nematic phase to a (chiral) smectic phase?\nCan the smectic and nematic phases coexist in LCE?\nOur response:\nWe thank the reviewer for this thoughtful comment. All these three phases result from the\nself-assembly of LC molecules into specific arrangements. Generally, with increasing\ntemperature, LC phases undergo a transition from smectic phase to nematic phase and then\nto isotropic phase, realizing an order-to-disorder transformation. This constitutes a\ntemperature-dependent hierarchy of structural order. Chiral nematic phase is a variant of\nthe nematic phase, formed by intrinsically chiral LC molecules or achiral LC molecules\ndoped with chiral agents at an appropriate temperature. This reflects the influence of\nchirality on the nematic phase.\nWe fully agree that specific mesogens play a decisive role in smectic phase formation,\nwhich is a result of the fact that the LC rod-like cores and flexible chains themselves are\nadapted to the lamellar arrangement of the smectic phase. Meanwhile, the elastomer\nformed by RM82—a commonly used nematic monomer—after undergoing specific\nsynthesis steps also has the possibility of exhibiting a smectic phase. For instance, in this\nwork, we used long-chain thiols to undergo an addition reaction with RM82, forming a\nlinear structure of \"long flexible chain–rod-like mesogen–long flexible chain\". After\npolymerization, the resulting structure exhibits low cross-linking density and high chain\nmobility. The self-assembly of mesogenic cores induces core-chain hierarchy, i.e., the\nformation of a lamellar structure. Naturally, the influence of this tendency is limited;\nmoreover, in a multi-domain cross-linked network, it is unable to form the nearly perfect\nsmectic phase alignment. Furthermore, our research findings are consistent with previous\nstudies (Ref. 40). Owing to the aforementioned arrangement and the coexistence of main\nchains and side chains in the polymer, the transition from the nematic phase to the smectic\nphase at an appropriate temperature is incomplete. Therefore, it is possible that the smectic\nand nematic phases coexist in LCE. (Advanced Functional Materials, 2023, 33, 2214918.)\n2) How is the formation of the smectic phase related to the chemical composition and\nnetwork structure of the system? Why is phase separation unable to occur in CLCE\ncontaining only EDDET?\nOur response:\nWe thank the reviewer for this insightful comment. In the crosslinked network, the self-\nassembly of LC mesogens is restricted. For example, it cannot easily undergo temperature-\ndependent phase transitions (crystal-smectic-nematic-isotropic) like small-molecule LCs.\nThe restriction of chain mobility by the cross-linked network is a factor that must be\nconsidered, which imposes higher requirements for phase transitions in polymers. The rod-\nlike LC mesogens, the inherent long spacer chains of RM82, and the long spacer chains of\nchain extenders all contribute to the formation of the smectic phase. (Soft Matter, 2017, 13,\n7537-7547) However, for the chiral nematic system in this work, merely extending the\nspacer chains is insufficient due to the presence of the helical structure. This gives rise to\nthe thiol-terminated side chains determined by the synthesis ratio—a strategy to enhance\nchain mobility.\nThe smectic phase requires both orientational order of LC cores and lamellar arrangement.\nThe long flexible chains of EDDET facilitate lamellar arrangement, but they only tend to\npromote the transition from the already orientationally ordered nematic phase to the\nsmectic phase. For the chiral nematic phase with a helical structure, the key issue lies in\nhow to induce the helical molecular arrangement into an orientationally ordered state\n(where the directions of molecular long axes are nearly uniform). At this point,\ncrystallizable ODT segments play a role that EDDET does not possess: the arrangement of\ncrystalline molecular chains is regular (with consistent directions and similar spacings).\nThis implies that the rod-like cores of nearby LC molecules acquire the characteristic of\norientational order along with the regular arrangement of crystalline molecular chains,\nthereby promoting the formation of the smectic phase.\nTo clarify the reason why phase separation unable to occur in conventional CLCE, we have\nrevised the manuscript as follows:\n\"It is noted that the performance difference between SS-CLCE and conventional CLCE\nindicated that the presence of ODT affected the ability to undergo phase separation. ODT\nsegments not only enabled polymer crystallization themselves but also promoted the\nformation of the to-be-discussed smectic phase. This is because the rod-like cores of nearby\nLC molecules acquire the characteristic of orientational order along with the regular\narrangement of crystalline molecular chains.\" (Highlighted in Results, page 9, lines 173-\n178)\n3) The text mentions C-CLCE. What is the main difference in the network structure between\nC-CLCE and SS-CLCE? What is its primary role in the experiment?\nOur response:\nWe thank the reviewer for this valuable question. We apologize for the insufficient\nexplanation of C-CLCE in this paper. As a control sample, it was insufficiently explained\nin the initial manuscript. Herein, we will elaborate on its role in the experiment in detail.\nDuring the standing process prior to photopolymerization, oligomers continuously undergo\nself-assembly of linear oligomers; prolonged standing leads to the formation of obvious\ncrystalline regions, which act as optical and mechanical defects in the film (Figure R5).\nTherefore, when investigating the optimal photopolymerization time point, we prepared\nsuch a control sample. The corresponding experimental procedure was as follows: after\nprolonged standing (>8 h), high-temperature annealing (68-100-68 °C) was performed to\neliminate defects, followed by photopolymerization. The resulting C-CLCE film\ntheoretically exhibits a higher chain extension degree but lacks the orientation effect\ninduced by solvent evaporation. There is no difference in chemical composition. The\nstructural difference between SS-CLCE and C-CLCE lies in the distribution along the\nhelical axis: the former tends to be vertical, while the latter is disordered. This determines\nthe presence or absence of reflected color, while the phase separation phenomenon occurs\ncollectively due to the existence of linear backbones and side chains. Therefore, the\nprimary role of the C-CLCE is to indicate that standing prior to polymerization is\nunfavorable for the film to exhibit N* phase characteristics. However, both samples show\nsimilar XRD patterns and DSC curves, suggesting the presence of the same phase states\nand analogous structures (with different orientation conditions). Given the identical raw\nmaterial ratios, this indicates that endowing hardening properties requires sacrificing\nstructural color performance. The differences in material performance after polymerization\ndemonstrate the importance of polymerization control.\nFigure R5. The appearance of the samples at different durations. (Supplementary Fig. 3)\nTo clarify, we have included the photographs of oligomers at different durations (Figure\nR5 as Supplementary Fig. 3) in the revised Supplementary Information. We also have\nrevised the manuscript as follows:\n\"Due to the long linear structure and crystallizable segment-containing characteristic of\nSS-CLCE oligomers, gradual self-assembly occurred during the evaporation film-forming\nprocess, leading to the formation of large-sized spherulites—which was detrimental to the\nintegrity of the polymer film (Supplementary Fig. 3). Therefore, this gave rise to the\ndiscussion on the selection of appropriate self-assembly conditions. When ODT was used\nas the primary chain extender, intriguing phenomena emerged. We selected 4 hours (a\nduration with no macroscopic defects observed) as the self-assembly time prior to\npolymerization, the resulting SS-CLCE presented white, and showed a controlled rigidity\nthat disappeared upon heating.\" (Highlighted in Results, page 7, lines 139-146)\n\"When the self-assembly time was further extended to 8 h or more, the influence of the\nauxiliary phase on the primary N* phase became significant, a large number of\nmacroscopic defects (crystalline regions) are generated, which seriously affect the\nuniformity of the film. To prepare uniform elastomer films, a heating (100 °C) and cooling\n(68 °C) process was applied to eliminate crystalline regions. The resulted CLCE was\ndefined as the controlled CLCE (C-CLCE), which was induced into a vertical alignment\nmode due to the absence of orientation effect induced by evaporation.\" (Highlighted in\nResults, page 8, lines 158-164)\n4) Through the aging process, the modulus of the CLCE increases. How much improvement\ndoes its work capacity show compared to traditional non-aged CLCE or traditional LCE?\nOur response:\nWe thank the reviewer for this thoughtful suggestion. Unfortunately, the SS-CLCE in this\nwork did not achieve actuating performance, as it did not undergo the stretching orientation\nprocess prior to photopolymerization. In addition, the programming in the experiment\ninvolved a change from a permanent shape (strip) to a temporary shape (others), which was\nfixed through phase separation hardening. Consequently, if it is intended to realize film\ncontraction for work output via thermal actuation, it is inevitable to eliminate phase\nseparation to release the shape fixation, and thus the improvement in modulus will no\nlonger exist. Nevertheless, we still calculated the enhancement of some mechanical\nproperties. For example, the fracture toughness of the material increased by 180% within\n24 hours at 30 °C (from 4.94 to 13.91 MJ/m³). In addition, the 100% deformation energy\n(U) of SS-CLCE at room temperature, which also reflects the energy-absorption capacity\nduring the material stretching process, increased by 1100% (from 0.2 to 2.4 MJ/m³). With\nthe extension of aging time, the toughness will be further improved (Figure R12).\nFigure R12. (a) The increase in material modulus leads to a greater absorption of energy\nduring deformation. (b) The time-dependent increase of deformation energy. (Figs. 2e and\n4c)\nTo supplement, we note that Kim et al. (Small 2025, 21, 2406493) reported that the\nintroduction of crystallizable segments into liquid crystal elastomers (LCEs) exerts a\nstrengthening effect on the materials. As stated in the abstract: \"The specially designed\nphotochemical muscles can undergo about 60% tensile stroke and provide 15 kJ m⁻³ of\nwork capacity in response to light, thus providing about three times and two times higher\nperformance, respectively, than previous azobenzene actuators.\" This excellent work\nenhanced the work capacity by improving the modulus and achieved actuation through the\nphotoresponsiveness of azobenzene rather than the thermally driven actuation related to\nthe mesogenic orientation of LCEs, thereby avoiding the impact of high temperatures on\nthe mechanical properties of the strengthened materials. Therefore, phase separation-\ninduced toughening and strengthening hold promise for improving work capacity,\nbut orthogonal control (or endowing driving capability at low temperatures) may be\nrequired.\n5) In Fig. 6c, why does the CLCE film appear white under natural light but show bright\nred under R-CP light? It is expected to see red color under natural light as well.\nOur response:\nWe thank the reviewer for this valuable question. It is noted that the visually observed\nwhite actually contains a faint orange-red color, which failed to be captured due to the\nmasking effect of the white color. Theoretically, right-handed CLCEs selectively reflect\nright-handed circularly polarized light of specific wavelengths. In this study, the helical\nstructures self-assembled by linear oligomers induced via the solvent evaporation method\nare arranged along the vertical direction, forming a multi-domain structure. The relatively\nweak orientation ability of solvent evaporation results in a wide distribution of helical\ndirections and pitches of the oligomers, which weakens the circular dichroism\ncharacteristics. Meanwhile, the difference in refractive index for light among different\nmicrodomains leads to intense light scattering, exhibiting non-selective unpolarized light.\nConsidering comprehensively, the white color under natural light is the combined\nresult of unpolarized light scattering and broad-peak reflection of right-handed\ncircularly polarized light. When a right-handed circular polarizer is employed, only the\nright-handed polarized light is retained. The central wavelength of the right-handed light\nlies in 630 nm, showing an obvious orange-red color) (Figure R13).\nFigure R13. Reflection spectrum of SS-CLCE in the phase-separated and unstretched state.\nIt can be observed that the central wavelength of N* phase reflection is at 630 nm, while\nthe reflection exhibits a broad peak and a high baseline caused by scattering spanning the\nentire visible light region, leading to a white appearance.\nTo clarify the white appearance, we have revised the manuscript as follows:\n\"The initial film appeared white with a faint orange-red reflection, corresponding to a broad\nreflection peak around 630 nm. This is because the helical structures in the sample had\nuneven orientations and variations in p at different positions, influenced by the relatively\nweak orientation force of solvent evaporation during preparation.\" (Highlighted in Results,\npage 16, lines 301-304)\n\"Due to the polydomain and phase-separated nature of the film, its non-selective left-\nhanded broadband reflection hindered the readability of the recorded information, the\nintensity of unpolarized reflection and scattering is reduced by half (left-handed\npolarization is blocked), and the intensity of right-handed polarized light centered at 630\nnm, dominated by the N* phase, remains unaffected. Thus, a distinct orange-red\nbackground was observed through a R-CP.\" (Highlighted in Results, page 25, lines 485-\n491)\n6) The formatting should be checked; for example, the font for \"°C\" in the figures is\ninconsistent with the rest of the text. The scale bar in Figure 6 is not labeled with\ndimensions.\nOur response:\nWe sincerely appreciate the reviewer for the careful review of this manuscript. We have\nrevised all the mistakes mentioned above. This is one of the figures with modified fonts.\nSince a large number of figures need to be revised, only one image is selected here as an\nexample (Figure R14).\nFigure R14. A figure example with the font of \"°C\" modified. (Fig. 2)\nAnd the revised text for the scale bar in Figure 6 are as follows:\n\"Photographs of the results of the information writing, decrypting and erasing. All scale\nbars in Fig. 6 are 1 cm.\" (Highlighted in the caption of Fig. 6)\n7) The following references may be helpful for introducing this work:\nMatter 2025, 8, 101950 (10.1016/j.matt.2024.101950); Adv. Fiber Mater. 2025, 7, 1010-\n1041 (10.1007/s42765-025-00539-4).\nOur response:\nWe thank the reviewer for this suggestion. These two reviews summarize the applications\nof LCE materials as stimuli-responsive smart soft matter in a wide range of fields through\nvarious regulation methods. They reveal the promising prospects of LCEs centered on\ndiverse morphologies and multiple regulatory approaches. CLCEs, the research object of\nthis study, as a branch of LCEs, can obtain guidance for research directions from these\nreviews. These reviews provide us with certain reference value, and we have cited them\naccordingly. They are cited as Refs. 19 and 24, respectively.\n\"19 Ma, J. & Yang, Z. Smart liquid crystal elastomer fibers. Matter 8, 101950 (2025). \"\n\"24 Yu, Y., Zhang, F., Liu, Y. & Leng, J. Smart Polymer Fibers: Promising Advances in\nMicrostructures, Stimuli-Responsive Properties and Applications. Adv. Fiber Mater. 7,\n1010-1041 (2025). \"\nReviewer #3 (Remarks to the Author):\nThe authors present an impressive and timely study on stiffness-switchable chiral liquid\ncrystal elastomers (SS-CLCEs), demonstrating 4D memory effects and rewritable photonic\nencryption. The topic is highly significant, and the work offers exciting potential for both\nfundamental understanding and practical applications. While I greatly appreciate the\nnovelty and experimental effort invested in this work, several aspects would benefit from\nfurther clarification, additional evidence, and expanded discussion. Overall, this\nmanuscript addresses an important challenge in stretchable photonic materials and\npresents novel findings on stiffness-switchable CLCEs. I commend the authors for their\ninnovative work. Nevertheless, clarification of the synthesis mechanism, quantitative\nanalysis of phase coexistence, improved imaging, and discussion of durability and\npractical considerations are essential to strengthen the impact of the study. Addressing the\npoints in below would significantly enhance the clarity, rigor, and overall contribution of\nthe manuscript.\nOur response:\nWe sincerely appreciate the reviewers for their in-depth review and encouraging comments\non this work, these detailed and insightful suggestions are of great significance to the work.\nWe have addressed all points put forward by the reviewer. Please see our detailed response\nbelow.\n1) Comparison with Prior Rigidity-Controlled Mechanochromism\nIn the Introduction, please compare this work more explicitly with earlier mechanochromic\nstudies where rigidity was tuned to control color changes (e.g., AFM 2024; Nat. Mater.\n2022), highlighting the distinct contributions of the present study.\n- Ref 1: “Optimized and Uniform Strain Control in Intrinsic Stretchable Mechanochromic\nMaterials with Color- and Polarization-Separating Encryption using Kirigami Cuts and\nRigid Strain-Stoppers,” Adv. Funct. Mater., 2422772 (2024).\nhttps://doi.org/10.1002/adfm.202422772\n- Ref 2: B. H. Miller, H. Liu, M. Kolle, Nat. Mater. 2022, 21, 1014.\nOur response:\nWe thank the reviewer for the suggestion. We have taken note of and referenced several\nstudies on rigid-controlled mechanochromic. The reported rigid-controlled\nmechanochromism involves regulatory approaches such as adjusting the crosslinking\ndegree; however, these methods fix the material properties during fabrication. Utilizing\nphotomasks to achieve modulus differentiation on a single film, which generates patterns\nafter mechanochromism, is simple and feasible, but each film can only stably display one\npattern without the capability of erasure and rewriting. Additionally, in another case of\nregulating film rigidity, matrixization is required—specifically, arranging multiple small-\narea CLCE films into a matrix (e.g., 5×5) fixed on the same commercial flexible substrate.\nThe stretching of the underlying substrate drives the tensile deformation of the top CLCE\nfilms to varying degrees, thereby realizing a patterning process with color distinction.\nIn summary, previous works are highly informative, but the localized heating method\nemployed in this study to reduce modulus enables non-directional patterning after film\nfabrication. Furthermore, by heating the entire film and re-aging it, new information can\nbe rewritten. This achieves a write-erase process on a single film (without the need for\nmatrixization) and without custom photomasks.\nWe have cited the first reference as Ref. 67 and the second reference as Ref. 70. We also\nhave revised the manuscript as follows:\n\"The previously described whole-film processing of the film enabled the retention of both\nits 3D shape and structural color. In contrast, localized processing allowed for the recording\nof encrypted textual information. Previous work reported stiffness control via crosslinking\ndegree. First, using photomasks on single films to form patterns (after deformation) via\ndifferential photopolymerization; Second, making matrices with small CLCE pieces of\nvarying crosslinking degrees for regional color differences.26,67,68 Similarly, differences in\nthickness will convert the same external force into different stresses, thereby resulting in\ncolor distinction during the stretching process.69,70 These measures fixed film modulus,\nprecluding erasure/rewriting (crosslinking control) or single-film color variation (dot\nmatrix). While prior studies are valuable, our work enabled post-fabrication non-\ndirectional patterning via localized heating to reduce modulus. Heating the entire film and\nre-aging allowed rewriting, achieving write-erase on a single film without matrixization or\ncustom photomasks.\" (Highlighted in Results, page 24, lines 468-479)\n\"67 Shin, J. H. et al. Optimized and Uniform Strain Control in Intrinsic Stretchable\nMechanochromic Materials with Color- and Polarization-Separating Encryption Using\nKirigami Cuts and Rigid Strain-Stoppers. Adv. Funct. Mater. 35, 2422772 (2025). \"\n\"70 Miller, B. H., Liu, H. & Kolle, M. Scalable optical manufacture of dynamic structural\ncolour in stretchable materials. Nat. Mater. 21, 1014-1018 (2022). \"\n2) Similarly, the novelty of this work should be clarified in relation to previous studies on\nthickness-driven color separation and multi-modulus CLCEs (e.g., Adv. Mater. 2023; LSA\n2025).\n- Ref 1: Adv. Mater., 2302456 (2023). https://doi.org/10.1002/adma.202302456\n- Ref 2: “Programmable optical encryption using thickness-controlled stretchable chiral\nliquid crystal elastomers,” Light: Science and Applications (LSA), 14, 136 (2025).\nOur response:\nWe thank the reviewer for this suggestion. We have already provided a response in\nSuggesion 1 simultaneously. We have cited the first reference as Ref. 68 and the second\nreference as Ref. 69.\n\"68 Nam, S., Wang, D., Kwon, C., Han, S. H. & Choi, S. S. Biomimetic Multicolor-\nSeparating Photonic Skin using Electrically Stretchable Chiral Photonic Elastomers. Adv.\nMater. 35, 2302456 (2023). \"\n\"69 Nam, S., Woo, S., Park, J. Y. & Choi, S. S. Programmable optical encryption using\nthickness-controlled stretchable chiral liquid crystal elastomers. Light Sci. Appl. 14, 136\n(2025). \"\n3) Role of ODT vs. EDDET in Synthesis mechanism\nThe necessity of ODT in inducing long side-chain formation in SS-CLCE should be\nclarified in more details. A more detailed mechanistic explanation contrasting ODT with\nEDDET would be valuable to highlight the uniqueness of this approach.\nOur response:\nWe thank the reviewer for this important suggestion. In the crosslinked network, the self-\nassembly of LC mesogens is restricted. For example, it cannot easily undergo temperature-\ndependent phase transitions (crystal-smectic-nematic-isotropic) like small-molecule LCs.\nThe restriction of chain mobility by the cross-linked network is a factor that must be\nconsidered, which imposes higher requirements for phase transitions in polymers. The rod-\nlike LC mesogens, the inherent long spacer chains of RM82, and the long spacer chains of\nchain extenders all contribute to the formation of the smectic phase. (Soft Matter, 2017, 13,\n7537-7547) However, for the chiral nematic system in this work, merely extending the\nspacer chains is insufficient due to the presence of the helical structure. This gives rise to\nthe thiol-terminated side chains determined by the synthesis ratio—a strategy to enhance\nchain mobility.\nThe smectic phase requires both orientational order of LC cores and lamellar arrangement.\nThe long flexible chains of EDDET facilitate lamellar arrangement, but they only tend to\npromote the transition from the already orientationally ordered nematic phase to the\nsmectic phase. For the chiral nematic phase with a helical structure, the key issue lies in\nhow to induce the helical molecular arrangement into an orientationally ordered state\n(where the directions of molecular long axes are nearly uniform). At this point,\ncrystallizable ODT segments play a role that EDDET does not possess: the\narrangement of crystalline molecular chains is regular (with consistent directions and\nsimilar spacings). This implies that the rod-like cores of nearby LC molecules acquire the\ncharacteristic of orientational order along with the regular arrangement of crystalline\nmolecular chains, thereby promoting the formation of the smectic phase.\nTo clarify the contrasting ODT with EDDET, we have revised the manuscript as follows:\n\"It is noted that the performance difference between SS-CLCE and conventional CLCE\nindicated that the presence of ODT affected the ability to undergo phase separation. ODT\nsegments not only enabled polymer crystallization themselves but also promoted the\nformation of the to-be-discussed smectic phase. This is because the rod-like cores of nearby\nLC molecules acquire the characteristic of orientational order along with the regular\narrangement of crystalline molecular chains.\" (Highlighted in Results, page 9, lines 173-\n178)\n4) Quantification and Control of Coexisting Phases\nWhen partial phases coexist (N*, SmC*, crystalline), please clarify how the phase fraction\nis quantified. Although the authors briefly mentioned, it is critical to judge the effectiveness\nof heterogenous control of the SC-CLCE. In addition, discussion of how these proportions\nmay be tuned through synthetic or processing conditions would strengthen the manuscript.\nOur response:\nWe sincerely thank the reviewer for this insightful suggestion. Regarding the phase fraction\nin phase separation, we cannot accurately calculate the exact percentage of different phases.\nHowever, we can determine the relative relationships between these different phases.\nFirst, the overall crystallinity of the material, which represents the approximate\nvolume proportion of crystalline microdomains, can be derived from the XRD/WAXS\npattern. Through peak splitting and fitting of the XRD/WAXS pattern, a broad diffuse peak\n(Peak 1) and crystalline peaks can be obtained (Figure R15). Using the calculation formula\nprovided in the Supplementary Notes, the degree of crystallinity (X ) is calculated to be\nc\n26.4%. Therefore, the volume ratios of the crystalline region and the amorphous region are\n26.4% and 73.6%, respectively.\nFigure R15. Process the WAXS spectrum to obtain the crystallinity. (Supplementary Fig.\n15a)\nSecond, we can use the DSC curve of the corresponding sample to determine the\nrelative relationship between the crystalline region and the ordered smectic phase\n(Figure R16). As indicated by the fitted curve, the enthalpy change of the smectic phase\ntransition corresponding to the first endothermic peak accounts for approximately 41% of\nthe total enthalpy change, while the broad asymmetric melting enthalpy change of polymer\ncrystallization accounts for 59%. This indirectly reflects the quantitative relationship\nbetween the crystalline regions and the smectic phases.\nFigure R16. Process the DSC curve to obtain the relative relationship between the\ncrystalline and the smectic phase.\nTo clarify, we have revised the manuscript as follows:\n\"Meanwhile, the sharp crystalline peaks in the X-ray diffraction (XRD) patterns clearly\nindicated the presence of crystallinity (X ) of 26%, reflecting the volume proportion of\nc\ncrystalline regions in the polymer, with the remainder being LC phases and amorphous\nregions.\" (Highlighted in Results, page 9, lines 181-184)\n\"Based on these findings, we inferred that the two independent endothermic peaks\nspanning 40 °C in the DSC curve corresponded to the phase transitions from the smectic\nphase to the N* phase and from polymer crystallization to the LC state, respectively. The\nenthalpy-change relationship corresponding to these two peaks implied the relative\nquantitative relationship between the smectic phases and the crystalline phases.\n(Highlighted in Results, page 14, lines 266-270)\nSince the objective of this work is to verify the enhancement potential of CLCEs, the main\ncomparison is made with traditional mechanically fixed CLCEs. The core sample in the\nmain text adopts a molar ratio of ODT to EDDET of 4:1, which simultaneously takes into\naccount the presence of side chains and sufficient crystallizable segments. By comparing\nwith samples containing more crystallizable segments (without side chains), it is explained\nthat the mere presence of crystallizable segments cannot achieve a significant enhancement\neffect (Figure R1). Due to the constraints of the article's logic and manuscript length, we\ncannot discuss more comparative samples again in the main text. However, we can provide\nadditional explanations and relevant data here (Figure R17), regarding the second point—\nproportion tuning.\nFigure R17. The XRD patterns of different molar ratios of ODT to EDDET indicate the\ndifference in crystallinity. The data for the ratios 4:1 and 0:1 are derived from those of SS-\nCLCE and conventional CLCE in the main text. (Supplementary Fig. 15b)\nBased on the variation trend of the XRD curves, we conclude that the proportion of\nODT (crystallizable segments) directly affects the degree of crystallization, which is\nconsistent with the conclusion reported in the previous work (Macromolecules\n2021,54,8987−8995). Finally, the differences in the mechanical properties of the films\nunder the same aging time but different aging temperatures in Fig. 4f also indicate the\nregulation of phase separation by processing condition (temperature).\nTo clarify, we have added Figure R17 as Supplementary Fig. 15b, we also have revised the\nmanuscript as follows:\n\"Furthermore, adjusting the ratio during the synthesis process can regulate the\ncrystallization properties, corresponding to the control of the crystallinity (Supplementary\nFig. 15b).\" (Highlighted in Results, page 13, lines 244-246)\n5) Domain Size of Partial Crystalline Structures\nPlease provide information on the approximate size of the mixed crystalline domains. Are\nthey macroscopic heterogeneous regions, or microscopic domains that give rise to\nmacroscopically homogeneous properties?\nOur response:\nWe thank the reviewer for this important suggestion. As mentioned earlier, polymerization\ncontrol is of great importance. An unreasonable preparation will lead to macroscopic\ncrystallization of oligomers, which exerts a negative impact on the polymerization process,\npolymer homogeneity, and mechanical properties (Figure R5). We avoided macroscopic\ndefects in the polymer through the selection of an appropriate duration, and simply\nproposed the nanoscale of polymer crystallization. Taking the two higher crystalline peaks\nin Figure 14 (green line and purple line) as examples, according to the Scherrer equation,\n𝐾𝜆\n𝐷 =\n𝛽cos𝜃\nthe grain size D is related to the diffraction angle θ and the full width at half maximum\n(FWHM) (β) of the diffraction peak. K is a constant as the shape factor, and λ is a constant\nas the wavelength of the incident X-ray. After calculation, the size corresponding to the\ngreen peak at 2θ = 19.1° is 5.9 nm, and the size corresponding to the purple peak at 2θ =\n24.4° is 7.7 nm. Therefore, the macroscopic properties are induced by the microscopic\ndomains.\nTo clarify, we have added Figure R15 (as Supplementary Fig. 15a) and Supplementary\nTable 2, we have we have also revised the manuscript as follows:\n\"Based on the Scherrer equation, the corresponding crystallite sizes were approximately\nseveral to a dozen nanometers (Supplementary Fig. 15a and Supplementary Table 2). \"\n(Highlighted in Results, page 13, lines 242-244)\nSupplementary Table 2. The crystal sizes from the WAXS curve. The results are\ncalculated using the Scherrer equation.\nPeak center (°) 17.6 19.1 21.0 22.6 24.4\nSize (nm) 13.8 5.9 5.7 8.7 7.7\n6) Data Collection in Figures 4a and 4b\nThe rationale for selecting data collection points away from the center of the film is not\nclear. Given the visual heterogeneity across the sample, this point requires explanation.\nOur response:\nWe thank the reviewer for this important suggestion. We would like to present our simplest\nreason regarding the selection of reflection data collection point.\nDuring the stretching process, the probe position of our spectrophotometer was kept\nfixed. However, stretching caused the center point of the film to move continuously,\nleading to a gradual deviation of the data collection points from the film center. Meanwhile,\nthe selection of our data collection points is also reasonably justified. First, we aimed to\nmaintain consistency in the measurements before and after aging. If we adjusted the probe\nto the film center every time the film was stretched to a certain length, this would be an\nexcellent choice for the relatively uniform heated state. However, to maintain consistency,\nif we also adopted the center-measurement method for the aged films, the resulting\nreflection spectra would make it difficult to observe a relatively linear shift in the reflection\nwavelength. This is because the presence of phase separation imparts high toughness to the\nfilm— the film will always start to undergo significant deformation at a certain point while\nremaining slightly deformed elsewhere, and the deformation will then gradually propagate\nacross the entire film, consistent with the extension of the blue region in Figure 4b.\nHowever, we also acknowledge that the used test method is indeed unconventional, so we\nwill provide multi-point tests of the reflection spectra in the following section, so as to\naddress the seventh question simultaneously.\n7) Spatially Resolved Characterization\nFor the experiments shown in Figure 4, multi-point characterization (edge-to-center\nmeasurements) would provide a clearer picture of spatial variations in optical and\nmechanical behavior. Please repeat and compare multi points in SC-CLCE regarding\nFigure 4.\nOur response:\nWe thank the reviewer for this important suggestion. We have conducted repeated\nexperiments, measuring three points (upper edge point, center point, and lower edge\npoint) simultaneously during the stretching process to demonstrate the\ninhomogeneity of the reflection color of the aged film. Based on the repeated\nexperiments and our existing data, we found that the significant fluctuations in the\nreflection spectra in the original Figure 4a are attributed to the lack of baseline calibration.\nTherefore, on the premise of ensuring that the actual stretch-induced color change visual\neffect remains unchanged, we have revised and supplemented the multi-point reflection\ntests (Figure R18). And we also confirm that the color-changing mechanism of SS-CLCE\nremains unchanged.\nFigure R18. Multi-point characterization of the SS-CLCE film: (a) upper edge point, (b)\ncenter point, and (c) under the heated state; (d) upper edge point, (e) center point, and (f)\nunder the aged state. (Fig. 4a and Supplementary Fig. 19)\nAs can be seen from the figure, the reflection data of each point on the film in the heated\nstate shows little difference, and the edge points exhibit a larger blue shift than the center\npoint, which is consistent with the optical images. For the film in the aged state, the\nreflection data of each point differs significantly: the lower edge point shows the fastest\nand most obvious change, followed by the upper edge point, and finally the center point.\nThis is also consistent with the optical images, reflecting the heterogeneity of deformation.\nTo clarify, we have replaced the reflection spectrum in Figure 4a with that from Figure\nR18 (b, d) as the test data of the center point, and the other data have been added as\nSupplementary Fig. 19. We have we have also revised the manuscript as follows:\n\"Since the regions connecting the edges and the center displayed intermediate colors, we\nalso collected the reflection data at the edge positions (Supplementary Fig. 19), these data\nreflected the differences between the center and the edge positions.\" (Highlighted in\nResults, page 18, lines 340-343)\n8) Thickness Dependence of Aging Effects\nThe temperature dependence of aging should be considered alongside film thickness. Is\nthere an optimal thickness at which the reported effects are most pronounced, or can\nmicrophase separation occur over a wide thickness range?\nOur response:\nWe thank the reviewer for this valuable suggestion. Regarding the thickness dependence\nof the aging effect, we have also observed it in experiments. In the initial manuscript, the\nthickness of our samples ranged from 80 to 200 μm, within which stable aging could occur.\nFurthermore, the reduction in film thickness caused by stretching during the programming\nprocess did not hinder aging-induced shape fixation, indicating that aging can take place\neven when the film is relatively thin. To verify whether thicker films exhibit the aging\neffect, we prepared a free-standing film with thickness variations using a mold tilting\nmethod (the central region ranged from 750 to 320 μm, and the edge reached up to 1200\nμm due to surface tension and other factors during preparation). The film with a uniform\nappearance was obtained. After aging, experimental samples were cut from different\npositions for XRD testing to evaluate uniformity (Figure R19).\nFigure R19. We prepared a wedge-shaped SS-CLCE film, and performed XRD\nmeasurements at several positions with different local thicknesses. (a) Approximate\nthickness of the prepared film. (b) Selection principle for the multiple testing points.\n(Supplementary Fig. 6a and b)\nFigure R19 presents the photographs of the film thickness, along with a schematic\nillustration of the subsequent XRD data measurement points. The XRD curves will be\npresented in the Suggestion 10, where we would like to address both the thickness\ndependence and the uniformity of aging.\n9) Vertical Temperature Gradients\nPlease consider the implications of applying vertical thermal gradients across the film (e.g.,\nbottom layer below Tg, top layer above Tg). Could such gradients induce non-uniform aging\nor novel structural effects across the thickness?\nOur response:\nWe thank the reviewer for this insightful suggestion. Based on the experimentally observed\nphenomena, temperature gradient inevitably leads to different degrees of microphase\nseparation. However, in practical operation, due to temperature fluctuations and slicing\nerrors, the tested XRD curves may contain certain deviations, but they can basically reflect\nthat differential temperature treatment results in non-uniform aging. For the selection of\nthe sample aging temperature, we chose 30 °C (a temperature with a fast-aging rate)\nand commercial ice packs to achieve the temperature difference based on operability.\nConsidering the melting and temperature rise of the ice packs, they were replaced every 4\nhours for 24 hours. Finally, the upper and lower parts of the sample were cut for XRD\ntesting (Figure R20).\nFigure R20. The effect of temperature gradient on the microstructure along the sample\nthickness direction. (a) Photograph of the sample treatment process: the bottom hot stage\nwas set at 30°C, and an ice pack was placed on the top and replaced every 4 hours for 24\nconsecutive hours. (b) To more easily observe the microstructural differences between the\nupper and lower surfaces, the aged sample was manually sectioned. (c) XRD curves of the\nsame film when the upper and lower surfaces were subjected to different temperatures. The\ncurves were normalized to clarify the relative relationship.\nFrom the experimental results, the temperature difference between the upper and lower\nsurfaces leads to a difference in crystallinity—specifically, crystallization is slower at low\ntemperatures and faster at high temperatures, which is consistent with the theory. Based on\nthe conclusions from our experiments, the difference in crystallinity can extend to a\ndifference in phase separation, thereby achieving a modulus distinction between the upper\nand lower surfaces. This modulus difference holds potential research value in the field of\nactuators. Given the core viewpoint of this work, we hope that the functionalization\nachieved by modulus differences induced by temperature gradients can be further\ninvestigated in future studies.\n10) Uniformity of Aging\nRelated to the above, how do the authors ensure that aging and microphase separation occur\nuniformly across the film thickness?\nOur response:\nWe thank the reviewer for this valuable suggestion. We clarify that the uniformity of SS-\nCLCE is favorable. First, the material system is monolithic, eliminating issues of poor\ncompatibility. Second, the films are obtained by evaporating the solvent from a\nhomogeneous solution, with no other differential treatment operations during the process.\nAs described in our response to Suggestion 8, we performed multi-point XRD tests on films\nwith thickness variations to verify the uniformity of the material's microstructure, and the\ntest results are shown in Figure R21.\nFigure R21. Multi-point XRD tests on the wedge-shaped film for verifying uniformity.\n(Supplementary Fig. 6c)\nThe XRD results simultaneously demonstrated the uniformity of the film's aging effect and\nits adaptability to thickness. Combined with the experiments in the main text, we can at\nleast conclude that the aging effect can occur within a wide thickness range of 80–800 μm,\nand uniform heat treatment temperature of the film leads to uniform aging.\nTo clarify, we have added Figures R19 and R21 as Supplementary Fig. 6, we also have\nrevised the manuscript as follows:\n\"We also fabricated a wedge-shaped film, and multi-point XRD tests demonstrated the\nuniformity of the microstructure across the entire film as well as the wide thickness range\nwithin which aging occurred (Supplementary Fig. 6).\" (Highlighted in Results, page 9,\nlines 184-186)\n11) Hybrid Temperature–Time Protocols\nSince both temperature and time strongly influence aging, could hybrid or sequential protocols\n(e.g., rapid initiation at higher temperature followed by stabilization at lower temperature)\nyield.\nOur response:\nWe sincerely thank the reviewer for this thoughtful suggestion. Our work have shown that\nspontaneous phase separation leads to a toughening and strengthening process over time,\nwhile temperature, as a key factor affecting chain mobility, influences the rate of\nstrengthening. The choice between the two will determine efficiency and rigidity. Earlier,\nwe also conducted corresponding studies on the influence of thickness, uniformity, and the\npossibility of gradient control. These verify that the hardening phenomenon is broadly\napplicable. Hybrid control of temperature and time is certainly feasible. We can infer that\nif the just-heated films are sequentially aged at higher and lower temperatures for a certain\nduration, according to the universal properties of polymer crystallization, the closer the\ntemperature is to the crystal melting point (below the melting point), the more perfect the\nformed crystals will be, and the higher the melting point will be; conversely, a temperature\nfar from the melting point will result in crystal defects and a lower melting point. This is\nthe reason why the melting point of polymers is generally referred to as the melting range,\nindicating the broad peak form of the melting peak. Therefore, we can anticipate that hybrid\ntemperature-time control will lead to a wider melting range of the polymer, and the\ncrystallization properties will also affect the phase transition of the smectic sequence,\nresulting in the broadening of the DSC curve. This is unfavorable for selecting appropriate\naging temperatures or heating temperatures in this work. And our work focuses on material\nhardening and the resulting memory effect, and hybrid control would complicate this\nstrategy. Thus, while we agree that the reviewers' suggestions will endow the material\nwith richer phase transition characteristics and potential significance, the\nintroduction of more comparative samples is not conducive to elaborating the\nviewpoints of this paper, after all, the best way to age is still to maintain a constant\ntemperature.\n12) Origin of Chevron SmC*\nIn Figure 3H, the appearance of a chevron SmC* phase is intriguing. Typically, chevron\nalignment arises from anchoring asymmetry associated with alternating up/down\nspontaneous polarization (Ps). Could the authors elaborate on why this occurs in their\nsystem?\nOur response:\nWe thank the reviewer for this crucial suggestion. We apologize for our misjudgment of\nthe specific smectic phase type (chiral or achiral). After confirming the smectic phase\narrangement via SAXS and references, we readily characterized it as a chiral smectic\n(SmC*) phase due to the presence of a chiral environment and it was a mistake. Guided by\nthis comment, we immediately recognized that the previous judgment of the SmC* phase\nwas arbitrary. This is because the LC monomer RM82 itself has no intrinsic chirality,\nthe chirality of the system originates from the chiral dopant LC756 introduced in a\nsmall amount, and the possibility of spontaneous polarization is absent. Therefore, we\nclarify that \"the existence of a SmC* phase\" is revised to \"the existence of a SmC phase\".\nSince all theoretical and performance analyses in this experiment do not utilize the special\nproperties of SmC*—it is only used as an auxiliary phase for microphase separation—this\nrevision does not affect the basic conclusions of this study.\nThe formation of chevron alignment was determined based on the azimuthal integration of\nSAXS (Fig. 3f). The data of the stretched film showed double peaks, corresponding to the\nseparation of directors, i.e., chevron alignment. This is referenced to previous works\n(Science 2024, 386, 1161–1168; Soft Matter, 2022, 18, 4803–4809). It is worth noting that\nthe aged SS-CLCE contains a conventional SmC auxiliary phase. After stretch-induced\norientation, the layered arrangement of LC molecules is compressed and automatically\naligned into a chevron shape.\nTo revise, we have replaced all occurrences of \"SmC*\" in the manuscript with \"SmC\". Due\nto the large quantity, we only list some of the revisions.\nFor example:\n\"... induce the main chains in a low-crosslink-density polymer network to participate in the\ntransition from the chiral nematic (N*) phase to the partly-formed smectic C (SmC) phase\"\n(Highlighted in Introduction, page 5, line 81)\n\"... which was larger than the 4.4 nm interlayer spacing shown by WAXS. This suggests\nthat the phase is SmC.\" (Highlighted in Results, page 15, line 276)\n\"... the originally pure N* phase of the crosslinked network spontaneously transformed into\nSmC and Cr regions under...\" (Highlighted in Discussion, page 26, line 510)\n13) Decoding Under Biaxial vs. Uniaxial Stretching for Decryption mode\nIn Figure 6 and Supplementary Video 4, decryption is observed under biaxial stretching\nbut not uniaxial. Please discuss the underlying reason, particularly in relation to the\nstability of right-handed CLC under RCP conditions. Relevant prior studies (AFM 2024,\nAFM 2023, AFM 2020) should be cited.\n-Ref 1: “Optimized and Uniform Strain Control in Intrinsic Stretchable Mechanochromic\nMaterials with Color- and Polarization-Separating Encryption using Kirigami Cuts and\nRigid Strain-Stoppers,” Adv. Funct. Mater., 2422772 (2024).\nhttps://doi.org/10.1002/adfm.202422772\n-Ref 2: “Optical Characteristics of Stretchable Chiral Liquid Crystal Elastomer under\nMultiaxial Stretching,” Adv. Funct. Mater., 2304506 (2023).\nhttps://doi.org/10.1002/adfm.202304506\n-Ref 3: Adv. Funct. Mater. 2020, 30, 1909537.\nOur response:\nWe thank the reviewer for this valuable suggestion. Previous work has investigated the\neffects of uniaxial stretching, biaxial stretching, and out-of-plane stretching on the\nreflection color of CLCEs. All types of stretching can compress the helical structure of\nCLCEs, reduce the pitch, and induce a blue shift of the reflection color. However, excessive\nuniaxial stretching will destroy the integrity of the CLCE helical structure and lose circular\ndichroism, resulting in structural color observable under both left and right circular\npolarizers. In contrast, biaxial stretching or out-of-plane stretching can compress the pitch\nwhile ensuring structural integrity, thereby maintaining selective circularly polarized\nreflection. However, in this study, a right-handed circular polarizer is used to filter out\nunnecessary left-handed circularly polarized light, enabling the circularly polarized\nreflected light of SS-CLCE to account for a larger proportion and thus exhibit a more\ndistinct structural color. Meanwhile, modulus differences are generated by locally\neliminating phase separation on the same film, thereby displaying the written information\nafter stretching.\nTo clarify, we have also revised the manuscript as follows:\n\"Previous work reported stiffness control via crosslinking degree: 1) using photomasks on\nsingle films to form deformation patterns via differential photopolymerization; 2) making\nmatrices with small CLCE pieces of varying crosslinking degrees for regional color\ndifferences.26,67,68 Similarly, differences in thickness will convert the same external force\ninto different stresses, thereby resulting in color distinction during the stretching\nprocess.69,70 These measures fixed film modulus, precluding erasure/rewriting\n(crosslinking control) or single-film color variation (dot matrix). While prior studies are\nvaluable, our work enabled post-fabrication non-directional patterning via localized\nheating to reduce modulus. Heating the entire film and re-aging allowed rewriting,\nachieving write-erase on a single film without matrixization or custom photomasks.\"\n(Highlighted in Results, page 24, lines 470-479)\n\"In this case, a right-handed circular polarizer (R-CP) is the first key to decrypt the\ninformation, the intensity of unpolarized reflection and scattering is reduced by half (left-\nhanded polarization is blocked), and the intensity of right-handed polarized light centered\nat 630 nm, dominated by the N* phase, remains unaffected.60,67\" (Highlighted in Results,\npage 25, lines 487-490)\nWe also have cited the first reference as Ref. 67, the second reference as Ref. 60 and the\nthird reference as Ref. 42.\n\"42 Kizhakidathazhath, R. et al. Facile anisotropic deswelling method for realizing\nlarge-area cholesteric liquid crystal elastomers with uniform structural color and broad-\nrange mechanochromic response. Adv. Funct. Mater. 30, 1909537 (2020). \"\n\"60 Kwon, C., Nam, S., Han, S. H. & Choi, S. S. Optical characteristics of stretchable\nchiral liquid crystal elastomer under multiaxial stretching. Adv. Funct. Mater. 33,\n2304506 (2023). \"\n\"67 Shin, J. H. et al. Optimized and Uniform Strain Control in Intrinsic Stretchable\nMechanochromic Materials with Color- and Polarization-Separating Encryption Using\nKirigami Cuts and Rigid Strain-Stoppers. Adv. Funct. Mater. 35, 2422772 (2025). \"\n14) Interpretation of Stress–Strain Data\nSince Figures 4a and 4b show clear spatial heterogeneity in color and reflectance, it is\nimportant to clarify which region (center, edge, etc.) the reported stress–strain curves\nrepresent.\nOur response:\nWe thank the reviewer for this valuable suggestion. We clarify that the stress-strain curves\ndo not correspond to a specific region but reflect the overall performance of the tested films.\nGiven the more pronounced spatial heterogeneity of the aged film, we use it as an example\nfor explanation, correlating the stress-strain curves with the actual stretching process.\n1. Elastic deformation stage (strain < 10%)\nThe rapid stress increase before the yield point corresponds to the elastic deformation of\nthe entire film reinforced by microphase separation. Within this stage, both deformation\nand color change are minimal.\n2. Initial microphase separation destruction stage\nWhen a specific point (stress concentration point) reaches the elastic deformation limit, the\ninitial microphase separation-reinforced structure is destroyed by mechanical forces. The\ndamaged microphases can no longer withstand higher stress, resulting in a slowed stress\nincrease rate or even a negative value. Meanwhile, the polymer chains at this location start\nto orient along the direction of the external force, while chains at other positions remain\nprotected by microphase separation without orientation. This corresponds to significant\ndeformation and narrowing at the specific location of the film, with the color changing\nfrom white to blue-green, while minimal changes are observed in other regions.\n3. Plastic deformation plateau stage\nAs the degree of polymer chain orientation at the stress concentration point increases, the\nstress balances with that at the adjacent microphase-reinforced regions. Further strain leads\nto the gradual orientation of non-oriented chains adjacent to the oriented ones. This\ncorresponds to the plastic deformation plateau with slow stress increase, where the blue-\ngreen, large-deformation region gradually expands, and the white region gradually\ndecreases until it disappears.\nIn summary, the stress-strain curves we provided represent the overall mechanical\nperformance of individual films, which is similar to the tensile properties of commodity\nplastics. Although local preferential strain occurs during the process (local necking first\noccurs at a specific point), this is also a reflection of the overall performance.\nTo clarify, we have also revised the manuscript as follows:\n\"Since stiffness changes are primarily reflected in the elastic deformation region, the study\nfocused on the strain range of 0 to 100% (Fig. 4c), although local preferential strain occurs\nduring the process (local necking first occurs at a specific point), this is also a reflection of\nthe overall performance.\" (Highlighted in Results, page 18, lines 350-353)\n15) Reflectance Data vs. Photographs\nThere appears to be a discrepancy between the reflectance spectra and the photographs in\nFigures 4a and 4b. The initial reflectance peak near 600 nm should correspond to a red–\norange appearance, which is not clearly visible in the images. Conversely, the blue-shifted\nstates appear visually clearer despite lower reflectance. A physical explanation (e.g., peak\nnarrowing, reduced diffuse scattering) would be helpful.\nOur response:\nWe thank the reviewer for this important suggestion. It is noted that the visually observed\nwhite actually contains a faint orange-red color, which failed to be captured due to the\nmasking effect of the white color. Theoretically, right-handed CLCEs selectively reflect\nright-handed circularly polarized light of specific wavelengths. In this study, the helical\nstructures self-assembled by linear oligomers induced via the solvent evaporation method\nare arranged along the vertical direction, forming a multi-domain structure. The relatively\nweak orientation ability of solvent evaporation results in a wide distribution of helical\ndirections and pitches of the oligomers, which weakens the circular dichroism\ncharacteristics. Meanwhile, the difference in refractive index for light among different\nmicrodomains leads to intense light scattering, exhibiting non-selective unpolarized light.\nConsidering comprehensively, the white color under natural light is the combined\nresult of unpolarized light scattering and broad-peak reflection of right-handed\ncircularly polarized light. When a right-handed circular polarizer is employed, only the\nright-handed polarized light is retained. The central wavelength of the right-handed light\nlies in 630 nm, showing an obvious orange-red color) (Figure R13). Finally, the more\nobvious blue color is attributed to the disappearance of the plateau in the visible light range\nin the late stage of stretching, the relative narrowing of the peak, and the reduction of the\ninfluence of the white background by the stretch-induced monodomain structure.\nFigure R13. Reflection spectrum of SS-CLCE in the phase-separated and unstretched state.\nIt can be observed that the central wavelength of N* phase reflection is at 630 nm, while\nthe reflection exhibits a broad peak and a high baseline caused by scattering spanning the\nentire visible light region, leading to a white appearance.\nTo clarify the white appearance, we have revised the manuscript as follows:\n\"The initial film appeared white with a faint orange-red reflection, corresponding to a broad\nreflection peak around 630 nm. This is because the helical structures in the sample had\nuneven orientations and variations in p at different positions, influenced by the relatively\nweak orientation force of solvent evaporation during preparation. Meanwhile, the\ndifference in refractive index for light among different microdomains leads to intense light\nscattering, exhibiting non-selective unpolarized light. Considering comprehensively, the\nwhite color under natural light is the combined result of unpolarized light scattering and\nbroad-peak reflection of right-handed circularly polarized light.\" (Highlighted in Results,\npage 16, lines 301-308)\n\"With further stretching, the peak became narrower as the film approached a monodomain\nstate; consequently, the blue color became more vivid while the white background\ngradually faded.\" (Highlighted in Results, page 16, lines 313-314)\n16) Clarity of Structural Colors in Photographs\nIn Figure 5c, the photographs do not clearly capture the described red/blue structural colors,\ninstead appearing milky and translucent. Higher-quality images or supplementary optical data\nare recommended.\nOur response:\nWe thank the reviewer for this important suggestion. As a signature characteristic of\nCLCEs, their structural color indeed requires additional attention. On the premise of\nmaintaining the original mechanical properties, stiffness switching performance, and phase\nseparation strategy unchanged, we have updated the physical display image (Fig. 5c) to\nimprove the image quality as much as possible.\nFigure R8. Demonstration of stiffness switching and shape-color integrated programming.\n(Fig. 5)\nWe have also replaced Supplementary Movies 2 and 3 accordingly. Please find them in the\nSupplementary Movies File.\n17) Durability and Fatigue Behavior\nThe SS-CLCE is described as reusable. However, has the shape-memory/resetting process\nbeen tested over tens or hundreds of cycles? Data on long-term durability, fatigue, and\nretention of optical/mechanical performance would be highly valuable.\nOur response:\nWe thank the reviewer for this constructive suggestion. The crosslinked network of SS-\nCLCEs is fully covalent, and the aging process relies entirely on the spontaneous ordered\narrangement between adjacent segments, so it theoretically possesses sufficient durability.\nIn practice, we also observed the expected repeatability during the testing of the basic\nproperties of SS-CLCEs. However, we did not provide sufficient data to illustrate\ndurability in the initial manuscript. Therefore, we have supplemented heated-aged cycle\ntests and the reflection spectra of the films before and after the cycles (Figure R6).\nFigure R6. Heating-aging cycle test and the reflection spectra after the cycles. (a, b)\nMechanical properties after heating and aging: the first 10 cycles are the results of aging at\n20 °C, and cycles 11 to 20 are the results of aging at 40 °C. (c) The reflection spectra before\nand after the cycles indicate no significant change in structural color and (d) their\nphotographs.\nFigure R6 indicates that the film exhibits excellent cyclic performance and durability, with\nreliable temperature and time dependence, and the cycles do not impair the structural color\ncharacteristics of the film.\nTo clarify, we have added Figure R6 as Supplementary Fig. 23, we have we have also\nrevised the manuscript as follows:\n\"At an optimal temperature, self-enhancement of mechanical properties can be achieved\nwithin a short time, whereas excessively low or high temperatures prolong or even prevent\nphase separation from occurring (Fig. 4g, bottom). Heated-aged cycle tests were conducted\nto demonstrate the stability of the self-reinforcement effect and the durability of the SS-\nCLCE. The mechanical properties after aging at different temperatures and the structural\ncolor after cycling both indicated the durability and fatigue resistance (Supplementary Fig.\n23).\" (Highlighted in Results, page 21, lines 407-412)\n18) Practicality of Aging Times\nWhile the room-temperature aging process is scientifically interesting, its timescale (tens of\nhours) may limit practical applications. Could the authors suggest or test strategies to\naccelerate aging (e.g., alternative chemistries, external stimuli) without sacrificing\nperformance?\nOur response:\nWe thank the reviewer for this insightful suggestion. Here is the comparison of\nprogramming times with previous work. In previous works, Ware et al. (Macromolecules\n2017, 50, 4267−4275) reported a crystallized LCE requiring \"at least 12 hours\" of aging\ntime at room temperature, attributed to the extremely low-crosslinking network with an\napproximate elongation at break of 500%. Norikane et al. (Macromolecules 2021, 54,\n8987–8995) reported that the introduction of long methylene chains into LCEs exerts a\npositive effect on crystallization, and specified the aging condition of 24 h at 20 °C. Kim\net al. (Small 2025, 21 ,2406493) reported that the introduction of crystallizable segments\ninto LCEs exerts a strengthening effect on the materials, and specified the aging condition\nas \"samples then stored overnight to be crystallized\". Ji et al. (Nature Communications\n2024, 15, 9902) incorporated crystallized LCEs into the LCE matrix to form a semi-\ninterpenetrating network, and the article states the following: \"The results indicated that\ntheir crystallization behaviors were observed after 1 day, and the crystallization process\ncould be mostly completed in 5 days.\" \nThanks to the reviewers' suggestions, we have realized the significance of shortening the\naging time. Therefore, we have adopted corresponding measures to minimize the\nprogramming time (including increasing the content of crystallizable segments and\nraising the programming temperature). This method is based on the temperature\ndependence discovered in our experiments combined with the crystallizable segments\nemphasized in previous work (Figure 4f). We chose to use ODT as the sole chain extender\n(increased from a ratio of 4:1 to 1:0), and the aging temperature of the prepared SS-CLCE\nfilms was set at 40 °C for the time-dependent tests (Figure R11).\nFigure R11. The result of the time-dependent test of SS-CLCE (the ratio of ODT to EDDET\nis 1:0). Stress-strain curves for strains ranging from 0 to 100% at different aging times at\n40 °C\nAfter adjusting the ratio and aging temperature, we observed a faster aging rate, with the\nmaximum rate occurring between 2 and 6 hours. At this point, 8 hours can be used as the\nprogramming duration, representing a significant improvement compared to the previous\ncondition. However, all data in the initial manuscript of this work were obtained from SS-\nCLCEs prepared with a molar ratio of ODT:EDDET = 4:1. This ratio can better illustrate\nour viewpoint—i.e., the promoting effect of side-chain functionalization rather than merely\nthe introduction of crystallizable segments. Therefore, we hope to retain the main data in\nthe main text and present the aforementioned experiments as supplementary information\nto provide a method for improving material performance.\nTo clarify, we have added Figure R11 as Supplementary Fig. 24, we have we have also\nrevised the manuscript as follows:\n\"Upon heating, it was also capable of reverting to its original state, thereby enabling the\nnext usage cycle. It is worth noting that the aforementioned programming time requires\nmore than 24 hours to achieve better memory effect. By introducing more crystallizable\nsegments and increasing the aging temperature to accelerate chain rearrangement, the\nduration can be further shortened to 8 hours (Supplementary Fig. 24).\" (Highlighted in\nResults, page 24, lines 462-466)\nPoint-by-point response to the reviewers’ comments\nTitle: Buprestidae Metamorphosis-Inspired Stiffening Photonic Elastomers\nfor Shape-Color Integrated Memory and Information Encryption\nManuscript ID: NCOMMS-25-60167A\nType: Article\nWe sincerely appreciate the editors and reviewers for handling and concerning our\nmanuscript, as well as their efforts to improve the quality of the manuscript. We have\nseriously considered all the comments of three reviewers and revised our manuscript\naccording to their helpful suggestions. A detailed point-by-point response is provided\nbelow. We have implemented changes that are highlighted yellow in the revised manuscript.\n(Reviewers’ comments: black italic font; our responses to the comments: in blue; what we\nrewrote in the revised manuscript: in blue and underlined.)\nReviewer #1 (Remarks to the Author):\nThe comments of reviewers have been carefully addressed, I recommend for publication.\nOur response:\nWe sincerely appreciate your recognition of our revision efforts, as well as your\nrecommendation of publication.\nReviewer #2 (Remarks to the Author):\nI have reviewed the authors' responses to the reviewers' comments and the corresponding\nrevisions made to the manuscript. The authors have addressed all the points raised. One\nthing, the scale bar in Figure S3 is missing. Other than that I have no further comments,\nand therefore recommend the manuscript for publication.\nOur response:\nWe sincerely appreciate your approval of the revised manuscript, as well as your\nrecommendation for publication.\nAdditionally, to address the missing scale bar issue, we have revised the legend of Figure\nS3 as follows:\n\"Supplementary Fig. 3. The appearance of the samples at different durations. As self-\nassembly time of the oligomers increases, obvious defects begin to appear on the surface.\nThe scale bar is 1 cm.\"\nAs markups are not permitted in the final submitted Supplementary Information (PDF),\nwe have not highlighted the revisions.\nReviewer #3 (Remarks to the Author):\nI appreciate the authors’ efforts in revising the manuscript and addressing the questions\nraised in the previous round of review. The revisions have substantially improved the\nquality of the paper, and most of the earlier concerns have been satisfactorily resolved.\nTherefore, I recommend the manuscript for publication in its current form.\nThank you.\nOur response:\nWe sincerely appreciate the reviewer's positive comments on our revision results, as well\nas their recommendation for the publication of our manuscript."}, {"round": 2, "reviewer_comments": {"reviewer_1": "The comments of reviewers have been carefully addressed, I recommend for publication.", "reviewer_2": "I have reviewed the authors' responses to the reviewers' comments and the corresponding revisions made to the manuscript. The authors have addressed all the points raised. One thing, the scale bar in Figure S3 is missing. Other than that I have no further comments, and therefore recommend the manuscript for publication.", "reviewer_3": "I appreciate the authors’ efforts in revising the manuscript and addressing the questions raised in the previous round of review. The revisions have substantially improved the quality of the paper, and most of the earlier concerns have been satisfactorily resolved.\nTherefore, I recommend the manuscript for publication in its current form.\nThank you."}, "author_response": "Point-by-point response to the reviewers’ comments\nTitle: Buprestidae Metamorphosis-Inspired Stiffening Photonic Elastomers\nfor Shape-Color Integrated Memory and Information Encryption\nManuscript ID: NCOMMS-25-60167A\nType: Article\nWe sincerely appreciate the editors and reviewers for handling and concerning our\nmanuscript, as well as their efforts to improve the quality of the manuscript. We have\nseriously considered all the comments of three reviewers and revised our manuscript\naccording to their helpful suggestions. A detailed point-by-point response is provided\nbelow. We have implemented changes that are highlighted yellow in the revised manuscript.\n(Reviewers’ comments: black italic font; our responses to the comments: in blue; what we\nrewrote in the revised manuscript: in blue and underlined.)\nReviewer #1 (Remarks to the Author):\nThe comments of reviewers have been carefully addressed, I recommend for publication.\nOur response:\nWe sincerely appreciate your recognition of our revision efforts, as well as your\nrecommendation of publication.\nReviewer #2 (Remarks to the Author):\nI have reviewed the authors' responses to the reviewers' comments and the corresponding\nrevisions made to the manuscript. The authors have addressed all the points raised. One\nthing, the scale bar in Figure S3 is missing. Other than that I have no further comments,\nand therefore recommend the manuscript for publication.\nOur response:\nWe sincerely appreciate your approval of the revised manuscript, as well as your\nrecommendation for publication.\nAdditionally, to address the missing scale bar issue, we have revised the legend of Figure\nS3 as follows:\n\"Supplementary Fig. 3. The appearance of the samples at different durations. As self-\nassembly time of the oligomers increases, obvious defects begin to appear on the surface.\nThe scale bar is 1 cm.\"\nAs markups are not permitted in the final submitted Supplementary Information (PDF),\nwe have not highlighted the revisions.\nReviewer #3 (Remarks to the Author):\nI appreciate the authors’ efforts in revising the manuscript and addressing the questions\nraised in the previous round of review. The revisions have substantially improved the\nquality of the paper, and most of the earlier concerns have been satisfactorily resolved.\nTherefore, I recommend the manuscript for publication in its current form.\nThank you.\nOur response:\nWe sincerely appreciate the reviewer's positive comments on our revision results, as well\nas their recommendation for the publication of our manuscript."}]

Decision letter