Programmable multimodal actuation in cholesteric liquid crystal elastomer hollow fibers beyond mechanochromism

Domain: biology
Published: 2026-03-27
Editorial outcome: major_revision

Abstract
Cholesteric liquid crystal elastomers (CLCEs) change color under strain, offering attractive prospects for soft robotics and photonic devices. However, the helical structure of CLCEs averages out the exceptional anisotropy and soft elasticity of the nematic phase, leaving little scope for also using the director orientation to program their thermal or mechanical actuation. Here, we develop programmable CLCE hollow fibers with longitudinal, circumferential, or twisted alignments via the integration of dynamic boronic ester bonds and mechanical force/pressure-induced orientation, all while preserving sufficient periodicity for structural color. Upon inflation, these fibers exhibit diverse motions—expansion, contraction, elongation, twisting—with synchronous color adaptation. Accordingly, we derive a membrane balloon model based on the non-ideal neo-classical LCE energy with suitable CLCE director profiles, successfully capturing key mechanical features including non-monotonicity and sub-criticality. This study provides a paradigm for the development of intelligent shape- and color-changing systems in a bespoke and versatile way.

Introduction
Liquid crystal elastomers (LCEs) are one of the most promising classes of smart soft materials, with a range of dramatic and useful properties arising from their combination of the mobile and switchable anisotropy of liquid crystals (LCs) and the large deformation mechanics of elastomers1-4. Most famous are nematic LCEs, which exhibit muscular contractile actuation along their alignment axis (director) upon heating through the nematic/isotropic phase transition, and also exotic “soft elasticity” in which some deformations can be accommodated by director rotation within the solid at almost zero elastic stress/energy5,6. Conversely, chiral nematic (cholesteric) elastomers (CLCEs) are known for their vivid structural colors and mechanochromism7-9. More precisely, the director in CLCEs follows the same periodic helical nanostructure as found in liquid cholesterics, leading to strong Bragg reflection of light with a wavelength λ determined by the pitch. In CLCEs, these helices are embedded in an elastic solid, which additionally enables pitch, and hence color, to be manipulated mechanically10-15. CLCEs are thus very promising for applications in various fields such as sensors16-19, information encryption20,21, and biomimetic camouflage22-24.

However, since a cholesteric helix samples all planar orientation directions equally, the price paid for these dramatic colors is that mechanically, CLCEs are overall isotropic in plane. CLCEs thus lack the actuation and global soft elasticity of simple nematic LCEs, and also cannot benefit from “director design” in which director patterns are used to sculpt complex shapes25 or complex soft-elastic mechanical responses26. CLCEs are thus something of a “one-trick pony”, offering color changes under mechanical strain, but little opportunity to control or produce the deformations themselves.

Pneumatic actuation, with its easy implementation and dramatic mechanical/shape change performance, has rapidly established itself as a facile and effective platform for soft robotics27,28. Inflatable nematic balloons/tubes/fibers, for instance, have been shown theoretically and experimentally to exhibit versatile actuation motions depending on their initial alignment, and also exceptional work capacities29-35. In contrast, recent studies on inflatable CLCEs, while they do exhibit attractive blue-shifts, remain confined to color changes without functional deformation, which sacrifices the versatility and designability of actuation motions22,36,37. Therefore, precisely programming the alignments of CLCEs is essential for exploring the tuning of both deformation pathways and colors guided by combining soft elasticity and pneumatic actuation. Overcoming such challenge promises unprecedented multimodal responsiveness in CLCE systems.

Drawing these ideas together, here we report an anisotropic deswelling-assisted template method to fabricate CLCE fibers with hollow geometries and structural colors (Fig. 1a, 1b, and 1c), then use thermo-activated exchange of boronic ester bonds, along with mechanical or pneumatic forces, to program such fibers with global nematic directors in longitudinal, circumferential, and twisted geometries (Fig. 1d). During subsequent inflation of these hollow fibers, we observe color shifts, but also a rich range of motions, including expansion, contraction, elongation, and twisting (Fig. 1e, 1f, and 1g). These phenomena can occur monotonically or non-monotonically and continuously via coupling of director rotation and ballooning instabilities. To understand our observations, we develop a mechanical model of programmed cholesteric hollow fibers, that is derived from the standard non-ideal energy of nematic elastomers, but with a suitable initial director profile that mimics the CLCE alignment after programming. This semi-analytical model successfully captures both highly non-trivial inflation mechanics of the CLCE hollow fibers, and their color changes. Taken together, this study thus demonstrates that the rich soft-elastic behaviors of nematic LCEs can be combined with the vivid colors of CLCEs to create pneumatic actuators that both shift in color and undergo bespoke and complex deformations on inflation. We hope this provides a paradigm for future work on multi-responsive CLCEs, in which the sophisticated possibilities for mechanical design opened by director programming in nematic LCEs can be combined with CLCE colors to create multi-responsive systems in which both shape and color response can be designed, optimized, or even addressed independently, advancing the development of adaptive color-changing and intelligent actuation systems.

Results
Fabrication and characterization of CLCE hollow fiber
The CLCE hollow fiber was prepared via a template method combined with anisotropic deswelling. In a typical experiment, as shown in Fig. 2a, a mold with a hollow ring structure was assembled using an inner capillary glass tube and an outer silicone tube. The CLCE precursor, containing RM257 as the mesogen, LC756 as the chiral agent, DODT and BDB as spacers, and PETMP as the crosslinker, was filled into the mold. Notably, BDB, which contains dynamic covalent B−O bonds enabling bond exchange, was synthesized following a reported procedure (Supplementary Fig. 1)38. When the molar content of BDB relative to the total spacers was x%, the sample was denoted as xBDB (20BDB was used in the experiment unless otherwise specified). Subsequently, a Michael addition reaction was conducted to form the first-step crosslinking network, accompanied by solvent evaporation. During this process, as the solvent mainly evaporated through the silicone tube, the LC molecules self-assembled into a periodic helical nanostructure39. Following this, a photo-crosslinking reaction under UV irradiation led to the formation of the second-step crosslinking network. After demolding, the CLCE hollow fiber was obtained. It is important to note that in the resulting CLCE hollow fiber, the helical arrangement of the LC mesogens was oriented radially (along the wall thickness direction), with the helical axis perpendicular to the fiber’s longitudinal and circumferential directions. Along the longitudinal direction (for example, at the surface of the fiber), however, the LC mesogens exhibited a polydomain distribution without directional arrangement.

The color of the CLCE hollow fiber could be easily tuned by adjusting the content of the chiral agent. As shown in Fig. 1b and Supplementary Fig. 2, CLCE hollow fibers with red, green, and blue reflection colors were successfully obtained. The structure of the CLCE hollow fiber was characterized using scanning electron microscopy (SEM). As shown in Fig. 1c, the longitudinal section of the CLCE hollow fiber exhibited a uniform structure and a smooth surface. The cross-section revealed a concentric annular structure, with an inner diameter of ~1300 μm, an outer diameter of ~2200 μm, and a wall thickness of ~450 μm. At higher magnification in SEM, a typical lamellar pattern was observed, indicating the helical alignment. To confirm the polydomain, polarized optical microscopy (POM) and X-ray diffraction (XRD) were performed. As shown in Fig. 2b, in the POM images, the CLCE hollow fiber showed no significant changes when rotated at 45° intervals, consistently displaying a certain brightness. It was further confirmed by XRD in Fig. 2c, where the XRD pattern displayed a symmetric ring, and the azimuthal scan showed a flat line. These were consistent with the polydomain feature of the obtained CLCE hollow fiber.

In summary, by utilizing an anisotropic deswelling-assisted template method, we successfully fabricated polydomain CLCE hollow fibers with significant structural colors, laying the foundation for subsequent actuation studies.

Pneumatic response performance of polydomain CLCE hollow fiber
The hollow structure of the CLCE hollow fiber facilitates its accommodation of air pressure. Since the polydomain CLCE hollow fiber was directly obtained through fabrication experiments, we first investigated its actuation behavior, selecting a red CLCE hollow fiber to allow for a larger visible color-changing range. As shown in Fig. 2d, one end of the CLCE hollow fiber was sealed and clamped, while the other end was connected to an air pump. Pneumatic actuation was carried out at 25 °C. The pressure difference between the inside and outside of the cavity was denoted as Δp. The initial fiber length is denoted as L0, the fiber length at a stated pressure as L, and the length strain is defined as the ratio of ∆L/L0, where ∆L = L − L0. The initial outer fiber diameter is denoted as D0, the outer fiber diameter at a stated pressure is referred to D, and the outer diameter expansion ratio/strain is defined as ∆D/D0, where ∆D = D − D0. It was observed that as Δp increased, the CLCE hollow fiber exhibited axial contraction and significant radial expansion. As illustrated in Fig. 2e, when Δp reached 80 kPa, further inflation caused continued radial expansion but axial elongation. The maximum axial contraction ratio reached ~17%, accompanied by a radial expansion ratio of ~44%. Regarding structural color, as shown in Fig. 2d, the color of the CLCE hollow fiber gradually underwent a blue shift as Δp increased, transitioning from the initial red to green at 60 kPa, and then to blue at 100 kPa, with its reflection wavelength changing from 608 nm to 424 nm. Further inflation to 120 kPa caused the reflection spectrum to shift to even shorter wavelengths (Fig. 2f and 2g). The entire continuous pneumatic process was shown in Supplementary Movie 1. Moreover, it can be observed that as the pressure increased, the circular polarization selectivity of the polydomain CLCE hollow fiber disappeared (Supplementary Fig. 3 and Fig. 4), indicating the formation of directional alignment and distorted structures.11 The mechanical response of the polydomain CLCE sample is given in Supplementary Fig. 5.

Additionally, the polydomain CLCE hollow fiber maintained stable deformation and color-changing performance after 100 actuation cycles under 100 kPa pressure, demonstrating its excellent cyclic performance and laying the foundation for further applications (Fig. 2h).

To better understand this complex deformation trajectory theoretically, we develop a membrane balloon model for the CLCE that incorporates director rotation and its resultant (semi-)soft elasticity. We describe the CLCE as a cylindrical membrane with initial radius R0, length L0 and thickness t0. Upon inflation, the balloon stretches L →λL0, dilates R →ηR0, and consequently thins t →t0/(λη) to conserve the elastomer’s volume. Working in (z, θ, ρ) cylindrical coordinates, the deformation gradient in the CLCE is thus simply F = diag(λ, η, 1/(λη)), which is constant throughout the membrane. To model the elastic response to these deformations, we then use the standard non-ideal neo-classical hyper-elastic energy density for a nematic elastomer fabricated with initial director n0, then subject to a deformation gradient F that rotates the alignment to the final state director n:
W(F, n0) = min[ 1/2 μTr(FTℓ-1(n)Fℓ(n0) + αF(I – n0n0T)FTnn)],
where ℓ(n) ≡ r-1/3(I + (r − 1)nn). (1)
The first term above describes an ideal nematic elastomer with shear modulus μ and polymer anisotropy r>1. This term alone exhibits perfect soft elasticity, in which “soft modes” of deformation of the general form F = ℓ1/2(n) ℓ-1/2(n0) can be accommodated by director rotation but without any increase in energy. The second “non-ideal” term encodes a bias for n to align with its fabrication direction, n0, causing these soft-modes to incur an energy proportional to the (small) coefficient of non-ideality, α. In our CLCEs, the initial director is planar, n0 = (cos θ, sin θ, 0), but twists through the thickness with helical pitch p, giving θ(ρ) = 2πρ/p, so the total elastic energy can be written as a thickness average E = π(R2out − R2in) L0 <W(F, n0)> with inner radius Rin and outer radius Rout. Finally, at a given pressure P, the deformation of the balloon is given by minimizing E − PV, (V being internal volume) over λ and η.

Conducting the thickness average and minimization numerically in Mathematica (see Theoretical supplement), using the measured balloon geometry, and the three material parameters obtained independently by fitting to monodomain stress-strain curves (Fig. 1f), we obtain a theoretical prediction for the shifting shape and color of the hollow fiber (Fig. 2i). Though agreement is not perfect, the theory captures the key surprise, which is that the balloon initially shortens then lengthens, while the color blue-shifts monotonically. To rationalize this, we consider that, as ever in cylindrical balloons, the hoop stress is twice the longitudinal stress. In a region with initial longitudinal alignment, this difference induces the director to rotate toward the circumferential direction, and, in isolation, in an ideal system, this would occur via a perfect soft mode F = diag(r-1/2, r1/2, 1) that causes radial dilation and longitudinal contraction; after the director reaches circumferential, no further rotation is available, so the response is like a normal rubber balloon, with longitudinal and radial expansion. The behavior of the CLCE balloon, with modest but non-monotonic longitudinal contraction, arises as a compromise between the initially more longitudinal regions and more circumferential regions within each helix, which must all deform in the same way. Inspired by the developed theory, these observed experimental behaviors could be attributed to the fact that, although the polydomain CLCE hollow fiber exhibited overall mechanical isotropy, its internal stress distribution under inflation became anisotropic, with the hollow fiber structure experiencing doubled circumferential (hoop) stress compared to longitudinal stress under the same pressure. This anisotropy subsequently led to director reorientation toward the circumferential direction for part of the director domain, resulting in dramatic longitudinal contraction. In particular, the longitudinal strain exhibits a plateau below 20 kPa, likely owing to the semi-soft behaviour and the degree of alignment. When the pressure reached around 80 kPa, the director reorientation was saturated and all the directors were circumferential. This is consistent with the result that axial contraction reached its maximum at this pressure. After that, the fiber got thinner by further inflating, resulting in the shortening of the helical pitch because of the volume conservation during inflation.

Combining all the experiments and theoretical simulations in Fig. 2, it can be concluded that the polydomain CLCE hollow fiber can simultaneously undergo deformation and color changes under pneumatic actuation, with the magnitude of these changes adjustable by pressure. During the experimental actuation process, the fiber exhibited maximum values of ~17% length strain, ~79% radial expansion, and a 223 nm reflection wavelength blue shift. The theory captures the key non-monotonic surprise of the experiment, which is attributed to director-rotation towards circumferential. Unlike in our later case, the quantitative agreement here is somewhat disappointing, which we attribute to our treatment of neighboring domains as independent, neglecting the complex micro-mechanics that can arise from cooperation40. Also, our unified theoretical model performs better in the semi-soft mode regime, whereas the deformation of a polydomain sample is partly in the “hard” mode, with no director rotation, since the polydomain contains fully helical directors. Nevertheless, the model already captures several key features, including a non-monotonic and small length change, a monotonic and large diameter change, and a large monotonic blue shift.

Pneumatic response performance of longitudinally aligned CLCE hollow fiber
The intrinsic mechanical anisotropy and (semi-)soft elasticity endow LCE materials with diverse pneumatic actuation motions29,30,34,35,41, which also holds potential for CLCE systems. To achieve this functionality, it is necessary to impart directional arrangements to CLCEs. However, the CLCE hollow fiber obtained through the aforementioned experiments lacked an overall orientation. To address this issue, we introduced boronic ester molecules into the chemical system, aiming to program an overall alignment of the CLCE hollow fiber through thermo-activated exchange of dynamic covalent B−O bonds. The effect of dynamic B−O bonds on the performance of the CLCE hollow fiber was investigated by varying the content of BDB. Differential scanning calorimetry (DSC) curves indicated that the LC-to-isotropic transition temperature (Tni) of the CLCEs with different BDB contents was approximately 84.5 °C (Supplementary Fig. 6). Stress relaxation tests of the CLCEs showed that the 20BDB sample relaxed approximately 80% of the stress within 60 minutes, while the 50BDB sample achieved complete stress relaxation (Fig. 3b), demonstrating the thermo-activated exchange capability of the dynamic covalent B−O bonds.

To obtain longitudinally aligned CLCE hollow fibers, the polydomain CLCE hollow fiber was stretched to twice its original length and maintained at 65 °C (20 °C below Tni) for 6 h. Due to the thermo-activated B−O bond exchange, the polymer network of the CLCE hollow fiber formed a new topological structure to adapt to the aligned state. After cooling to room temperature and removing the fiber from the clamp, longitudinally aligned CLCE hollow fibers were obtained (Fig. 3a). Notably, since stretching reduces the wall thickness of the hollow fiber and causes a blue shift in the reflection color, polydomain fibers with an initial reflection wavelength in the near-infrared (NIR) range were selected to ensure that the resulting longitudinally aligned CLCE hollow fibers exhibited a red color. As shown in Supplementary Fig. 7, in this experiment, the reflection wavelength of the CLCE hollow fiber before longitudinal alignment programming was 920 nm, which blue-shifted to 682 nm after programming. The alignment state of the CLCE hollow fiber before and after programming was investigated using POM and XRD. As shown in Fig. 3c and Supplementary Fig. 8, the CLCE hollow fiber was bright under POM before programming, with no significant changes when rotated at 45° intervals. In contrast, after programming, the sample appeared completely dark when its long axis was parallel to one of the polarizers, and reached maximum brightness when rotated 45° relative to the polarizer, indicating that the programmed CLCE hollow fiber achieved almost homogeneous longitudinal alignment, while maintaining enough residual wobble alignment to preserve the structural color (same for other programmed alignments). As shown in Fig. 3d, the XRD patterns changed from a ring to a pair of diffraction arcs, consistent with the fact that the CLCE hollow fiber transitioned from a polydomain to an aligned monodomain structure after programming. The order parameter f of the longitudinally aligned CLCE hollow fiber was 0.63, as determined by the Hermans–Stein orientation distribution function42-44, indicating good alignment along the long axis. The above results demonstrated that a red, longitudinally aligned CLCE hollow fiber can be obtained through programming using thermo-activated B−O bond exchange.

Next, pneumatic actuation was performed on the longitudinally aligned CLCE hollow fiber. As shown in Fig. 3e, when Δp reached 60 kPa, the CLCE hollow fiber exhibited almost no deformation. When Δp reached 80 kPa, a clear and sudden expansion occurred, accompanied by substantial axial contraction, indicating a sub-critical instability. This sudden deformation contrasted with the gradual deformation observed in the polydomain CLCE hollow fiber. The critical pressure Δp at which the CLCE hollow fiber began to undergo abrupt deformation was defined as Δpc. Based on these observations, it can be concluded that the instability occurs between 60 kPa and 80 kPa. It was also observed that when Δp exceeded Δpc, the CLCE hollow fiber began to exhibit slight reverse elongation along with further radial expansion. Throughout the process, the maximum axial contraction ratio of the longitudinally aligned CLCE hollow fiber was ~50%, with a corresponding radial expansion ratio of ~130% (Fig. 3f). In terms of color change, as shown in Fig. 3e, the CLCE hollow fiber remained red as Δp increased, with a slight blue shift in its reflection spectrum (Fig. 3g and 3h). Although a drastic contraction occurred at 80 kPa, the reflection wavelength shifted only from 655 nm to 605 nm and remained within the red region. This is because, in the ideal case, pure director rotation does not alter either the fiber thickness or the photonic reflection band. Once the directors had fully rotated into the circumferential direction, further increases in pressure induced the thickness thinning, causing the reflection color of the CLCE hollow fiber to gradually shift from red to blue (from 605 nm to 497 nm). These results demonstrated that although the CLCE hollow fiber underwent large deformation at Δpc, its wall thickness did not decrease substantially. The entire continuous pneumatic process was shown in Supplementary Movie 2. Moreover, it can be observed that the CLCE hollow fiber exhibited no circular polarization selectivity—neither in its initial longitudinally aligned state nor after reaching the Δpc and transitioning to a circumferential alignment—indicating that the aligned samples possess a distorted structure (Supplementary Fig. 9 and Fig. 10). Additionally, 100 pneumatic actuation cycles at 120 kPa confirmed the actuation stability of the CLCE hollow fiber, demonstrating its potential as a dual-deformation and color-changing component for future applications (Fig. 3i).

We notice that several previous studies have examined how soft-elasticity and inflation are expected to combine in cylindrical nematic balloons with initially longitudinal alignment29-32. The key mechanics are that, since inflation always generates a hoop stress that is twice the longitudinal stress, the balloon initially inflates via a soft-mode, in which the director rotates to the circumferential direction. As observed experimentally30, the balloon actually gets shorter. Furthermore, during director rotation, the soft elastic modes of deformation demand shears that must twist the balloon. In strictly longitudinal balloons, rotation and twist are equally likely to occur in either sense, likely leading them to cancel out macroscopically29,31. However, these phenomena have not been analyzed in CLCEs.

To quantitatively understand the experiments, we use the same energy form but with the anchored director pointing towards the axial direction superposed by a small oscillation, θ(ρ) = 0.05 sin(2πρ/p). The oscillation is caused by the incompatibility of the director rotation through the thickness during the mechanical programming, yielding the programmed director pointing almost but not perfectly along the longitudinal direction through the thickness, and allowing the structural color to survive programming. Again, the theoretical model is solved numerically for the pressure-controlled ballooning problem. As shown in Fig. 3j, using the same material parameters, our model successfully captured the main mechanical response. In particular, both the length and the diameter have a large jump at a critical pressure, with length shortening and diameter increasing. Meanwhile, the thickness change is also calculated which predicts the color change accurately (see the theoretical manifestations in Fig. 3j), showing that blue shift largely arises above the critical pressure. As previewed in the polydomain case, an ideal (α = 0) longitudinal balloon would jump to a circumferential alignment at zero pressure via a soft mode, F = diag(r-1/2, r1/2,1), with radial dilation, longitudinal expansion, and interior volume increasing by r1/2. In CLCEs, this transition is delayed by non-ideality and the initial director fluctuation, but as anticipated in previous work29, it remains a subcritical jump. To confirm this mechanism, we plot the director rotation implied by our theory versus pressure in Fig. 3k. We see that the director rotation and the jump emerge simultaneously, confirming the jump is associated with the soft mode, and thus fundamentally different from a usual neo-Hookean balloon. Taken together, the experimental results and theoretical simulations demonstrated that the longitudinally aligned CLCE hollow fiber responded to air pressure, achieving maximum values of ~50% axial contraction, ~165% radial expansion, and a reflection wavelength blue shift of up to 176 nm. Inspired by the theory, this anomalous inflation behavior was primarily attributed to the simultaneous director reorientation and ballooning instability, under the dominant hoop stress5,45. This caused the circumferential direction to deform more easily during inflation, resulting in radial expansion and simultaneous axial contraction. In addition, due to the semi-soft elasticity of CLCEs, the LC mesogens of the CLCE hollow fiber exhibited almost no rotation below Δpc 46-49. Upon reaching Δpc, a slight increase in Δp induced significant rotation of the LC mesogens. The simultaneous rotation of all mesogens from the longitudinal to the circumferential direction macroscopically manifested as a sudden axial contraction of the CLCE hollow fiber. Moreover, when the pressure was increased beyond Δpc, the mesogen rotation was saturated and this led to further axial elongation and radial expansion as normal balloon.

From the results shown in Fig. 3, it can be concluded that the CLCE system containing B−O bonds exhibits effective dynamic bond exchange capability. Thermo-activated programming of polydomain CLCE hollow fibers can yield longitudinally aligned CLCE hollow fibers. The simultaneous shape and color changes of the longitudinally aligned CLCE hollow fiber under pneumatic actuation are attributed to its mechanical anisotropy and soft elasticity, during which the LC mesogens rotate from longitudinal to circumferential alignment. Notably, the distinct “plateau-then-jump” response presents opportunities for designing functional devices, such as threshold-type optical sensors and multi-stage soft actuators. By leveraging the pneumatic actuation-induced adaptability alongside the dual deformation and color-changing capabilities, the practical application scope of CLCE materials is expected to be further expanded.

Pneumatic response performance of circumferentially aligned CLCE hollow fiber
Different directional programming of LC mesogens may lead to distinct actuation behaviors. Longitudinally aligned CLCE hollow fibers can be obtained through simple axial stretching and polymer network rearrangement. However, achieving circumferential alignment in fibrous materials by applying circumferential force remains a challenge. Surprisingly, pneumatic actuation, as a method of applying mechanical force, provided an opportunity to obtain circumferentially aligned CLCE hollow fibers. As mentioned in the previous section, longitudinally aligned CLCE hollow fibers undergo a transition where the LC mesogens rotate from the axial to the circumferential direction upon reaching Δpc. If this oriented state is fixed, circumferentially aligned CLCE hollow fibers can be obtained. As shown in Fig. 4a, circumferential alignment programming of the CLCE hollow fiber was achieved by combining pneumatic actuation and dynamic covalent B−O bond exchange. Dynamic mechanical analysis (DMA) revealed that the Young’s modulus of the monodomain CLCEs decreased with increasing temperature (Fig. 4b)35,50. Therefore, in the experiment, circumferential alignment of the CLCE hollow fiber was programmed at 65 °C under a lower pressure of 70 kPa. Heating for 6 h allowed sufficient rearrangement of the topological network, resulting in circumferentially aligned CLCE hollow fibers. Notably, since the CLCE hollow fiber was inflated around Δpc, its color remained in the red state. Thus, samples with reflection wavelengths in the red range were selected for programming, and the resulting circumferentially aligned CLCE hollow fibers also exhibited a red color. To verify the orientation state, POM and XRD tests were conducted. Fig. 4c shows that when the long axis of the CLCE hollow fiber was parallel to one polarizer, the POM image appeared dark, whereas when the long axis was at a 45° angle to the polarizer, the POM image appeared bright, indicating a directional arrangement. The XRD pattern displayed a pair of distinct diffraction arcs, with the orientation direction perpendicular to the axial direction of the CLCE hollow fiber (The long axis of the fiber sample during testing was perpendicular to the beam stopper). The order parameter f was calculated to be 0.60, indicating that the circumferentially aligned CLCE hollow fiber was well-oriented (Fig. 4d). These experimental results demonstrate that by inflating the longitudinally aligned CLCE hollow fiber to rotate the LC mesogens into a circumferential state, while heating to induce bond exchange reactions, red circumferentially aligned CLCE hollow fibers were successfully obtained.

Under pneumatic actuation, as shown in Fig. 4e and Supplementary Movie 3, the CLCE hollow fiber exhibited a gradual axial elongation accompanied by radial expansion as the inflation pressure increased. When the pressure reached 200 kPa, the maximum axial elongation ratio was ~14%, and the maximum radial expansion ratio was ~25% (Fig. 4f). The color gradually changed from red to blue, with the corresponding reflection spectrum shifting from 611 nm to 453 nm, showing an approximately monotonic linear relationship with the change in pressure (Fig. 4g and 4h). This behavior is consistent with the pneumatic response of longitudinally aligned CLCE hollow fibers after reaching Δpc, as shown in Fig. 3. Additionally, the circumferentially aligned CLCE hollow fiber exhibited excellent stability over 100 cycles of pneumatic actuation (Fig. 4i), demonstrating its reliability for practical applications.

The actuation is theoretically predicated by the same method, with the programmed anchored director pointing circumferentially superposed by a small oscillation: θ(ρ) = 0.5π + 0.05 sin(2πρ/p). As shown in Fig. 4j, the main features of the length change, diameter change, and color change are captured by the theory. In contrast with the longitudinal alignment case, the length and diameter changes exhibit no jumps, because the director is already circumferential which gives no room for further director reorientation (Fig. 4k). However, the length change predicted by our model is noticeably smaller than that observed in experiments. We attribute this discrepancy to the isotropic modulus assumed in our original neo-classic energy model, whereas in reality the modulus is anisotropic along and perpendicular to the director. To address this, we also employ a modified model (Theory-2 in Fig. 4f) that incorporates soft elasticity and modulus anisotropy51, which yields improved predictions (see the theoretical supplement for details). Nevertheless, we primarily retain the original model, as it already captures the main features with satisfactory agreement.

From the results shown in Fig. 4, it can be concluded that the method of applying force through inflation enables the formation of circumferentially aligned CLCE hollow fibers, and the oriented state can be fixed using thermal exchange of dynamic B−O bonds. The circumferentially aligned CLCE hollow fibers can respond to pneumatic actuation, producing simultaneous axial elongation of ~14%, radial expansion of ~25%, and a blue shift of 158 nm in color under a pressure of 200 kPa. During pneumatic actuation, circumferentially aligned CLCE hollow fibers exhibit both elongation and expansion, achieving a large wavelength shift within a small strain range, which shows great potential for applications in strain sensors, information displays, and other fields.

Pneumatic response performance of twisted CLCE hollow fiber
By controlling the direction of the alignment, the mechanical anisotropy of CLCE hollow fibers could be programmed, thereby generating distinct pneumatic actuation motions and performances, such as the contraction of longitudinally aligned CLCE hollow fibers and the elongation of circumferentially aligned CLCE hollow fibers. However, the aforementioned two alignments are orthogonal to the long axis of the fiber. If the alignment of mesogens in CLCEs forms a certain angle with the long axis of the fiber, i.e., a twisted alignment, what kind of pneumatic actuation behavior would occur? We conducted an investigation into this matter. First, to achieve twisted alignment, during the programming process, we simultaneously stretched and twisted the polydomain CLCE hollow fiber, causing the LC mesogens to rotate at a certain angle along the long axis of the fiber (Fig. 5a). Heating was then applied to activate dynamic B−O bond exchange to fix the alignment. The degree of twisting was quantified by the twist density τ0, which is given by: τ0 = ∆θ/L0, where ∆θ is the torsional angle introduced into the CLCE hollow fiber and L0 is the length of the CLCE hollow fiber. Through thermal programming, we successfully fabricated CLCE hollow fibers with τ0 of 9° mm⁻¹ and 18° mm⁻¹. It should be noted that the hollow structure would flatten if τ0 exceeded 18° mm⁻¹, which was the maximum value investigated in this study. Additionally, twisting in clockwise and counterclockwise directions resulted in opposite chirality. Notably, to ensure the twisted CLCE hollow fiber exhibited a red color, we selected samples with reflection spectra in the NIR range for programming. Fig. 5b shows POM images of the left-handed twisted CLCE hollow fiber with τ0 of 9° mm⁻¹ and 18° mm⁻¹, respectively. It can be observed that the surface of the CLCE hollow fiber exhibited twisted textures, which can be attributed to the torsional stretching during preparation. The bias angle θ between the alignment direction of the twisted textures and the long fiber axis can be calculated as: θ = tan⁻1(Rout τ0), where Rout is the outer radius of the CLCE hollow fiber. The theoretical bias angles calculated for the CLCE hollow fibers in Fig. 5b were 7.6° and 15.2°, which closely matched the experimentally measured average values of 6.4° and 14.7°. Moreover, when the long axis was parallel to one of the crossed polarizers, the POM image of the CLCE hollow fiber appeared bright, and the transmitted light intensity reached its maximum when the long axis was at a 45° angle to the polarizer. The right-handed twisted CLCE hollow fiber with τ0 of 9° mm⁻¹ and 18° mm⁻¹ exhibited the same phenomenon (Supplementary Fig. 11). This differed from the previously investigated polydomain CLCEs, which exhibited birefringence at all angles, as well as from the longitudinally and circumferentially aligned CLCE hollow fibers, which both appeared completely dark when the long axis of the fiber was parallel to one of the polarizers. These results indicate that the mesogens in the twisted CLCE hollow fiber possessed a twisted alignment along the long axis. The twisted alignment of mesogens within the left-handed CLCE hollow fiber with τ0 of 9° mm⁻¹ and 18° mm⁻¹ was further confirmed by XRD, as shown in Fig. 5c. Compared to uniaxial alignment, the spot pattern gradually transformed into a wider arc as τ0 increased in twisted CLCE hollow fibers. The order parameter of the CLCE hollow fiber decreased to 0.61 and 0.58 when the twist density τ0 increased to 9° mm⁻¹ and 18° mm⁻¹, respectively. The reduction in the degree of orientation along the long axis of the fiber may be attributed to the alignment of mesogens along the torsional direction, deviating from the uniaxial alignment31,32,52. From the results above, it can be concluded that a CLCE hollow fiber can be programmed with a designed twisted alignment by controlling the twist density and chirality.

We further investigated the pneumatic actuation behavior of twisted CLCE hollow fibers. Fig. 5d shows images of the left-handed CLCE hollow fiber with τ0 of 18° mm⁻¹ during inflation. It can be observed that, as Δp increased, the CLCE hollow fiber demonstrated rotation, which became more pronounced due to the rotation of the clamp. The rotation angle ϕ was calculated as the angle between the clamp axis (black dashed line) and its initial position (gray dashed line) at different pressures Counterclockwise angles are recorded as negative (−), while clockwise angles are recorded as positive (+). Combining Fig. 5d and Supplementary Movie 4, when the pressure ranged from 0 to 60 kPa, the left-handed CLCE hollow fiber rotated counterclockwise (from the top view). When the pressure increased to 80 kPa, the fiber rotated counterclockwise to its maximum angle and then jumped backwards in rotation. After stabilization, further inflation caused the CLCE hollow fiber to rotate clockwise. During this process, the fiber rotated counterclockwise to a maximum angle of approximately 163°, then rotated clockwise by approximately 330° to +167° at 80 kPa, and reached a maximum rotation angle of approximately +185° at 140 kPa (Fig. 5e). Simultaneously, under pneumatic actuation, the CLCE hollow fiber also exhibited axial contraction and radial expansion, as shown in Fig. 5f. The magnitude of length contraction significantly increased at 80 kPa (Δpc), with a maximum contraction ratio of ~48%. Beyond this point, as Δp increased, the fiber exhibited axial elongation and radial expansion, similar to the deformation trend of longitudinally aligned CLCE hollow fibers. This rotation and deformation behavior can be attributed to the uniaxial and helical orientation of mesogens along the twisted CLCE hollow fiber. During inflation, the internal pressure increased, and the circumferential expansion force caused the mesogens to deflect toward the circumferential direction, resulting in length contraction and torsional deformation.

The left-handed CLCE hollow fiber with τ0 of 9° mm⁻¹ was also investigated (Fig. 5e and Supplementary Fig. 12). It exhibited counterclockwise rotation and axial contraction before reaching 80 kPa, rotating to a maximum angle of approximately 213° at 80 kPa before reversing its rotation by approximately 206° to −7°, with a maximum contraction ratio of ~48%. Beyond 80 kPa, the CLCE hollow fiber continued to rotate counterclockwise but exhibited axial elongation. Compared to the left-handed sample, the right-handed CLCE hollow fiber exhibited opposite rotation directions but similar rotation angles and deformation trends under pneumatic actuation.

In terms of color, as shown in Fig. 5g and 5h, the reflection wavelength of the twisted CLCE hollow fiber gradually blue-shifted as the pressure increased. After reaching 80 kPa, due to simultaneous radial expansion and axial elongation, the pitch length decreased more significantly, increasing the color-changing sensitivity. To demonstrate the reliability of the pneumatic actuation of twisted CLCE hollow fibers, as shown in Fig. 5i, we conducted 100 cycles of inflation at 140 kPa, laying a foundation for its further applications.

To rationalize this rich twisting behavior, we again used our mechanical model, now with a director profile θ(ρ) = θ0 +0.05 sin(2πρ/p), that describes a small residual thickness oscillation superimposed on the main director making fixed angle θ0 with longitudinal. Importantly, in this case, the balloon deformation is also allowed to include a shear component, Fθz = γ, which is included in the minimization and, when non-zero, describes the pneumatic twisting of the balloon. In contrast with the longitudinal balloons, the initial bias angle in the helical balloons drives the choice of a single sign of γ, meaning that the shears turn into the macroscopic twists that we observe32, enabling another mode of deformation. In the theoretical prediction, we choose the twist density τ0 close to the experimental values. The main direction θ0 of the anchored director can be calculated according to τ0. The geometric parameters Rout, Rin, L0, the polymer anisotropy r, and the non-ideality parameter α are chosen to be the experimental values or fitted from the monodomain experiment independently (or close). Due to the inherent symmetry of our model, the theoretical solutions for left- and right-handed twists are symmetric as well. As shown in Fig. 5e, 5f, 5h, and 5k, the numerical predictions from our model closely match the experimental pneumatic actuations, particularly capturing the twist/reverse-twist transitions and the jumps in length. Additionally, the predicted thickness changes enable computation of the resulting color shifts, which show good agreement with experimental observations. A further examination based on the theoretical model shows that the director reorientation caused by the hoop stress fundamentally governs the twist/reverse twist behavior and the length jump. From the above results, it can be concluded that upon inflation, the twisted CLCE hollow fiber first underwent torsional rotation and axial contraction. At Δpc, it untwisted and reversed its rotation, exhibiting both axial contraction and radial expansion. Beyond Δpc, the fiber exhibited axial elongation, accompanied by a blue shift in color.

In summary, by utilizing dynamic covalent bonds, CLCE hollow fibers with designed twisted structures can be achieved. Under pneumatic actuation, due to the twisted alignment of mesogens, the CLCE hollow fiber exhibited not only length contraction but also torsional deformation. Notably, the entire process involved two-directional motion, including twisting and untwisting rotations, with higher twist densities resulting in greater overall rotation angles. Additionally, the pneumatic actuation process was accompanied by a blue shift in structural color, providing responses in both shape and color. This twisted CLCE hollow fiber enriches the deformation modes of CLCE fibers as actuation units and expands the application scenarios of CLCEs as stimulus-responsive materials.

Methods
Materials
1,4-bis-[4-(3-acryloyloxypropyloxy)benzoyloxy]-2-methylbenzene (RM257) (97%) was purchased from Chemfish Co., Ltd. The chiral dopant LC756 (95%) was purchased from Nanjing Xinyao Technology Co., Ltd. 3,6-dioxa-1,8-octanedithiol (DODT) (98%), pentaerythritol tetra(3-mercaptopropionate) (PETMP) (95%), 1-hydroxycyclohexyl phenyl ketone (I-184) (99%), benzene-1,4-diboronic acid (98%), 1-thioglycerol (99%), and ethanol (99.5%) were purchased from Adamas. Dipropylamine (DPA) (98%) was obtained from TCI. Toluene was purchased from TGREAG. Magnesium sulfate and heptane were obtained from Greagent. Tetrahydrofuran was purchased from Energy Chemical. UV-curable adhesive (8500 Metal) was purchased from Ergo. The silicone tube and capillary glass tube are commercially purchased products. The aforementioned materials were used as received without any additional purification.

Synthesis of 2,2’-(1,4-phenylene)-bis[4-mercaptan-1,3,2-dioxaborolane] (BDB)
BDB was synthesized following a previously reported method38. Benzene-1,4-diboronic acid (1.5 g, 9 mmol) and 1-thioglycerol (2.0 g, 18.5 mmol) were dissolved in a mixture of tetrahydrofuran (40 mL) and water (0.1 mL). Magnesium sulfate ( 4.0 g) was then added. After stirring at room temperature for 24 h, the mixture was filtered and concentrated. The resulting solid was subsequently purified by repeated cycles of filtration and washing with abundant heptane, followed by concentration to afford the target compound as a white solid.

Fabrication of CLCE hollow fiber
In the first step, 0.6025 g of RM257 and 0.0174 g of LC756 were weighed into a glass vial, with LC756 accounting for 2.8 wt% of the total mass of the LC monomers. Then, 450 μL of toluene was added, and the mixture was heated to 80 °C to dissolve completely. After cooling to room temperature, 0.1265 g of DODT, 0.0527 g of BDB, 0.0386 g of PETMP, and 0.0041 g of I-184 were added. Finally, 0.100 g of a DPA solution diluted with toluene at a volume ratio of 1:50 was added and thoroughly mixed to form the precursor.

In the second step, a mold was assembled by fitting silicone tube I (Фin: 2.2 mm, Фout: 3.2 mm) over a capillary glass tube (Фin: 0.6 mm, Фout: 1.3 mm). Approximately 1 cm of silicone tube II (Фin: 1.4 mm, Фout: 2.2 mm) was inserted at one end of the mold as a spacer to align the centers of silicone tube I and the capillary glass tube, ensuring uniform wall thickness of the resulting hollow fiber. The LC precursor was then vacuum-filled into the mold from the other end. Upon completion, another silicone tube II was inserted at this end. The mold was placed in a fume hood for 12 h to allow solvent evaporation and the proceeding of the first-stage Michael addition reaction.

In the third step, the mold was exposed to 365 nm UV light at an intensity of 1.0 mW cm−2 for 0.5 h to complete the second-stage photocrosslinking. After this, the sample was soaked in ethanol for 4 h to facilitate its removal from the mold. Finally, the ethanol was completely evaporated to obtain the CLCE hollow fiber.

The CLCE hollow fibers fabricated using the proportions outlined in the above experimental process exhibited reflection wavelengths within the NIR range. To obtain red CLCE hollow fibers, the LC756 content was adjusted to 4.0 wt% of the total LC monomer mass. For green and blue CLCE hollow fibers, the LC756 content was 4.9 wt% and 5.3 wt%, respectively.

The orientation process of CLCE hollow fiber
(i) For longitudinally aligned CLCE hollow fiber: The obtained polydomain CLCE hollow fiber with a NIR wavelength was stretched to twice its original length and fixed, at which point it showed a red color. It was then placed in an oven at 65 °C for 6 h to allow for the exchange of dynamic B−O bonds, fixing the orientation state of the fiber. After cooling to room temperature and removing from the fixture, a red, longitudinally oriented CLCE hollow fiber was obtained. (ii) For circumferentially aligned CLCE hollow fiber: The longitudinally oriented CLCE hollow fiber was placed in an oven at 65 °C and connected to an air pump for inflation at increments of 10 kPa. As the air pressure increased to a certain value, the length of the CLCE hollow fiber decreased. When the length of the CLCE hollow fiber reached its minimum, the air pressure was maintained, and it was left in the oven at 65 °C for 6 h to allow for the rearrangement of the dynamic covalent network and fixation of the orientation of the LC mesogens. After cooling to room temperature, a circumferentially oriented CLCE hollow fiber was obtained. (iii) For twisted CLCE hollow fiber: The obtained polydomain CLCE hollow fiber with a NIR wavelength was stretched to twice its original length while being twisted. In this work, samples with a length of 2 cm were subjected to 180° and 360° left-handed twists, as well as 180° and 360° right-handed twists. After being placed in an oven at 65 °C for 6 h to program the orientation, twisted CLCE hollow fibers with varying twist densities and chiralities were obtained.

Characterization of CLCE hollow fiber
1H NMR of BDB was collected by a nuclear magnetic resonance apparatus (Ascend TM 400 MHz, Bruker) with samples dissolved in CDCl3. POM images of CLCE hollow fiber were obtained using a Nikon Eclipse Ti microscope equipped with a digital camera (Nikon DS-U3), captured between crossed polarizers in transmission mode. DSC was performed using a TA Q2000 DSC system. Samples were heated from −40 to 140 °C at a heating rate of 20 °C min⁻1. XRD patterns of CLCE hollow fiber were recorded using a Bruker D8 Discover diffractometer. The stress-strain test was conducted using an Instron 3342 tension tester at a tensile rate of 5 mm min⁻1. DMA tests were conducted on a TA Q800 DMA system. The samples were stretched at a force rate of 1.0 N min⁻1 until failure to obtain stress-strain curves at temperatures of 25, 45, 65, and 85 °C. The near-linear portion within 10% strain was used to calculate the Young’s modulus. For stress relaxation tests, samples with different BDB contents were rapidly stretched to a strain of 5% and held at 65 °C. Reflection spectra were recorded using a Wyoptics PC2000 spectrometer. The SEM images were obtained by a field emission SEM (SU-8010, Hitachi).

Characterization of the pneumatic response performance
One end of the CLCE hollow fiber sample was inserted into a needle (19G or 21G, selected based on the sample size) and fixed with UV-curable adhesive. The needle was connected to an air pump. The other end was sealed with UV-curable adhesive, and a 0.6 g iron clamp was attached to the tip. The sample was pneumatically actuated by applying the pressure in increments of 10 kPa, with the maximum pressure adjusted according to the sample’s condition to prevent bursting. After each pressure adjustment, the sample was allowed to stabilize, and its shape and color were recorded using a camera.

Theory
Here we model the CLCE hollow fiber in (z, θ, ρ) cylindrical coordinates, with initial inner radius Rin, outer radius Rout, length L0 and thickness t0. Upon inflation, the balloon stretches L →λL0, dilates R →ηR0, and consequently thins t →t0/(λη) to conserve the elastomer’s volume. The deformation gradient F in the CLCE is thus given by
F = [λ 0 0; 0 η 0; 0 0 1/(λη)], (2)
in the cylindrical coordinates, where the shear γ is cancelled out in the polydomain, longitudinal and circumferential cases but survives in the helical case.

We then adopt the non-ideal neo-classical hyper-elastic energy density3, shown in Equation (1), to simulate the ballooning of CLCE fibers, where μ is the shear modulus, r>1 is the polymer anisotropy and α is the small non-ideality. In the following simulations, μ, r and α are the only three material parameters employed. Here, n0 is the anchored director during programming. In our programmed CLCE case, n0 remains on the (z, θ) plane but twists through the thickness, given by n0 = (cos θ(ρ), sin θ(ρ), 0). The rotation angle θ(ρ) is set to be θ(ρ) = θ0 + δ sin(2πρ/p), where θ0 is determined by the second crosslink (e.g. θ0 = π/2 for the circumferential pattern), δ in the second term is a small number indicating the director oscillation through the thickness, and p is the pitch of the twisted director in CLCEs which is given by h/Np (thickness/number of pitches). In the twist alignment case, the angle θ0 is obtained by the measured bias angle as mentioned in the main text.

Applying the homogeneous deformation gradient F across the thickness, the overall elastic membrane energy per unit area is given by an integral over the thickness ρ:
W̃(λ, η, γ) = ∫ RoutRin W(F, n0)dρ. (3)
Since the thickness is an integer multiple of the pitch, the integration cancels out the pitch dependence and depends only on the thickness. Accordingly, the total energy, including the elastic energy and the pressure-volume work, is given by
Wtotal(P, λ, η, γ) = π(R2out − R2in)L0 W(F, n0) − πR2inL0 λη2P. (4)
The inner radius Rin, outer radius Rout, and initial length L0 are obtained from experiments (Table 1). We then fix the pressure P and minimize the total energy to obtain (λ, η, γ) and the corresponding deformation gradient F. The twisting angle ϕ in Fig. 5 can be obtained from γ as ϕ = γL0 / (ηRout). The color change is directly related to the thickness change. According to the reported literature3,69, the measured wavelength λRT is a linear function of the thickness t by λRT = nave t / Np, where nave is the average refractive index and Np is the number of pitches. Thus, the theoretical wavelength is given by λRT ∝ t0 /(λη). With all the deformation parameters and wavelength shifts obtained, the theoretical configurations during inflation can be obtained (e.g. Fig. 2j, 3j, 4j, 5j).

In the four experiments, we perform the similar minimization with different distribution of θ(ρ) to obtain λ, η, γ for a given pressure P, and then plot the length strain, diameter strain and twist angle against pressure. It should be noted that, in our simulations, the geometrical parameters Rout, Rin, L0 are obtained from the experimental data (Table 1) and the material parameters (the polymer anisotropy r, non-ideality parameter α and shear modulus) are fitted from the monodomain experiment independently (or close). As shown in the figures, our methods successfully capture the key features of the experiments, indicating that they are grounded in the correct underlying physics.

The geometric data of the fibers are given in Table 1. The distribution θ(ρ) for the four experiments and the material parameters are
1. Polydomain. θ(ρ) = 2πρ/p, r = 5.5, α = 0.05, µ = 350 kPa.
2. Longitudinal alignment. θ(ρ) = 0.15 sin(2πρ/p), r = 5.5, α = 0.05, µ = 350 kPa.
3. Circumferential alignment. θ(ρ) = π/2 + 0.05 sin(2πρ/p), r = 5.5, α = 0.05, µ= 350 kPa.
4. Twist alignment.
(a) 18-Right. θ(ρ) = π/12.2+ 0.2 sin(2πρ/p), r = 5.5, α = 0.05, µ = 370 kPa.
(b) 9-Right. θ(ρ) = π/28.1+ 0.2 sin(2πρ/p), r = 5.5, α = 0.05, µ = 400 kPa.

To better account for the anisotropic modulus—which is expected to yield improved predictions in the circumferential and the monodomain case—we adopt an alternative model (Theory-2 in Fig. 4f) that captures both semi-softness and modulus anisotropy51. The corresponding hyper-elastic energy density is formulated as
W(F, n0) = min[ 1/2 μ1 Tr(FTℓ-1(n)Fℓ(n0)+αF(I – n0n0T)FTnn) + 1/2 μ2 (Tr(ℓ1/2(n0)FTℓ-1(n)Fℓ1/2(n0)n0n0T) – 1)2], (5)
where the first term is the same as the previous model, while the second term incorporates the anisotropy (a smaller μ2 corresponds to a smaller modulus perpendicular to the director). Specifically, the material parameters in the model (Theory-2 in Fig. 4f) are r = 5.5, α = 0.05, μ1 = 350 kPa, μ2 = 122.5 kPa, and for the circumferential case θ(ρ) = π/2 + 0.05 sin(2πρ/p).

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "This work presents new findings suggesting that programming nematic orientation in hollow CLCEs (and the resulting anisotropy) enables multimodal pneumatic actuations. While I acknowledge that this is an interesting strategy/observation, I have a few reservations that need to be clearly addressed. In my opinion, even if these question marks are resolved unambiguously, this work still lacks a level of significance or profound implication that meets the high standard of Nature Communications, from either a fundamental or an application perspective. My comments are as below:\n(1) My major concern is the authors’ claim that the reactive mesogens rotate from a longitudinal (or polydomain) alignment to a circumferential alignment during pneumatic inflation. In my view, this is overstated. The schematic illustration in this paper implicitly assumes the bistability of reactive mesogens, i.e., mesogens adopt either longitudinal or circumferential alignment. However, there is no basis to think that such discrete states can be energetically stable, nor that inflation alone can drive a well-defined transition between them. I would agree with a partial director rotation, but it seems too dramatic to assert that the mesogens can undergo a definite 90° rotation while being chemically crosslinked. If dynamic bond exchange plays any role (which I presume is unlikely), the reported cyclability would be difficult to reconcile.\n(2) Figure 4d, WAXS data, is presented as the key data supporting the author’s claim that circumferential alignment is observed after inflation. This is the part where my reservation arises, because the X-ray image is rotated by 90° relative to other WAXS patterns such as Figure 3d (I can tell this by the position of the beam stopper). This is very critical.\n(3) I strongly recommend that the authors perform in-situ experiments to directly observe the alignment rotation during inflation.\n(4) The authors define that the ∆pc for the CLCEs with a longitudinal alignment is 80 kPa, but I disagree. The ∆pc appears to be rather 60 kPa.\n(5) I disagree with the statement on page 12 line 285-288. A drastic change in the contraction is concurrent with the wavelength. I can see a linear trend from 60 kPa to 120 kPa.\n(6) I disagree with the statement on page 9 line 217-218. The agreement between experimental results and theoretical simulations is more than a little disappointing. I think the theory is quite off from reality (Figure 2e & Figure 2g). Figure 2g has obviously a linear trend.\n(7) How do the helical structures behave as longitudinal or circumferential alignment occur? Detailed discussion is required, possibly based on experimental data.\n(8) The degree of alignment in CLCEs does seem to have a distinct impact on anisotropic behaviors of CLCEs during pneumatic actuation. It determines the range of pressures that the CLCEs can resist, benefited from the anisotropic nematic ordering. I think that though it is narrow, the CLCEs with polydomains also seemingly have that persistent (plateau) pressure range, from 0 to 20 kPa. The correlation between the alignment and the anisotropic behaviors of CLCEs is indeed new knowledge that this work brings; however, I believe that this finding is not sufficiently novel or unprecedented to warrant the publication in Nature Communications.\n(9) There are many recent works related to hollow CLCE fibers (e.g. Adv. Mater. 2025, 37, 2504461; Adv. Sci. 2025, 12, e04487). I think that relevant work should be well acknowledged and properly compared with the current work in the introduction. In particular, while the deswelling-assisted template method in this work seems the identical method used in Adv. Sci. 2025, 12, e04487, the authors did not properly mention the prior work.\n(10) The authors should use clear and straightforward terminology throughout the manuscript. For example, on page 1 line 21, nematic phases are not parents of cholesteric phases (i.e., a cholesteric phase is not a subphase of nematic phase).", "reviewer_2": "This work presents a significant advancement in the field of soft smart materials by developing programmable cholesteric liquid crystal elastomer (CLCE) hollow fibers with multimodal pneumatic actuation and synchronous color changes. The authors successfully combine dynamic covalent chemistry, director programming, and pneumatic control to achieve complex deformation modes, which are coupled with dynamic structural color shifts. To understand these phenomena theoretically, the authors develop a unified theoretical model using non-ideal LCE energy and solve a ballooning instability problem. The theoretical results agree with the experiments well, revealing that the instability involving director rotation plays a significant role. This work sets a new benchmark for the field of adaptive color-changing and intelligent actuation systems.\nOverall, the paper is well-structured and written. The methodology is robust, the results are compelling, and the theoretical framework provides valuable physical insight. The topic and the quality match the requirements of Nature Communications. I highly recommend its publication.\nHere are some comments for authors to consider and further improve the work.\n1.During the programming process, the CLCE hollow fiber needs to undergo stretching, twisting, or pneumatic expansion to align the liquid crystal mesogens. Providing the mechanical properties of the CLCE hollow fiber before programming is crucial for completing the experimental information.\n2.For the polydomain sample, which lacks mechanical anisotropy and directional orientation, why does the CLCE hollow fiber initially undergo axial contraction rather than expansion upon inflation?\n3.The current work focuses on pneumatic actuation, which requires a physical connection to an air pump. Is it possible to achieve wireless or remote actuation to free the system from such constraints?\n4.The authors have developed a method combining dynamic covalent bonds with mechanical/pneumatic fields to achieve various alignment programming of CLCE hollow fibers. Conceptually and practically, what are the main breakthroughs and innovations of this strategy compared to traditional alignment methods for CLCE or LCE fibers?\n5.We’ve seen some work on the ballooning instability of LCE balloons. Please clarify what are the differences between the inflation of an LCE balloon and a CLCE balloon.\n6.In Figure 3 (longitudinal alignment), the wavelength keeps almost unchanged in a relatively large range of inflation. What is the mechanism behind this phenomenon? Could this point be used to design an actuator or some other applications?", "reviewer_3": "This was a very entertaining paper, and I found the results interesting. Achieving the alignments in the LC balloons was noteworthy, and the study was quite thoroughly done. I have few comments:\n• Figure 1g. I suggest the authors state in the legend what the arrows represent. It is a bit of a difficult story, and it would help a lot if the authors distinctly state that the arrows delineate the mesogen alignment and not, for example, the helical axes.\n• This may be a naïve question, but I ask it anyway. Is the mesogens in the polymerized film are forced to rotate towards the longitudinal direction, I assume this force is felt all through the depth of the helix. As the individual mesogens collectively rotate along the longitudinal, does this not affect the reflection band? I would assume this lowers the pitch, resulting in a red shift. However, the thickness decreases, tightening the pitch. Which feature wins out under extreme extension?\n• Ln 266: “while maintaining enough residual wobble alignment to preserve the structural color” Is there any estimation of the % reflection from the fibers? The only plot I see has 'relative' values. Can the authors estimate the fractional reflection?"}, "author_response": "Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education Department of Chemistry Tsinghua University Beijing 100084, China Tel: +86-137-1822-0695 E-mail: zyang@tsinghua.edu.cn 1 February 2026 Dear Dr. Virginia Valderrey Berciano, Manuscript ID: NCOMMS-25-87415-T Title: “Beyond mechanochromism: Programmable multimodal actuation in cholesteric liquid crystal elastomer hollow fibers” We have carefully considered reviewers’ comments and made revisions (highlighted in bright yellow in the revised manuscript) as detailed below. Reviewer #1 Comments: This work presents new findings suggesting that programming nematic orientation in hollow CLCEs (and the resulting anisotropy) enables multimodal pneumatic actuations. While I acknowledge that this is an interesting strategy/observation, I have a few reservations that need to be clearly addressed. In my opinion, even if these question marks are resolved unambiguously, this work still lacks a level of significance or profound implication that meets the high standard of Nature Communications, from either a fundamental or an application perspective. Reply: We truly appreciate that the reviewer acknowledges that our work is interesting, and also the care with which they have scrutinized the manuscript. We hope the referee’s technical questions are addressed clearly below. However, we must challenge the idea that our work lacks the level of significance required for Nature Communications. We believe our work is a very significant step forward for cholesteric liquid crystal elastomers, as we show, for the first time, how their shifting structural colors may be combined with the anisotropic soft elasticity and director rotation of nematic LCEs. This work thus unites two quite different aspects of LCE science—cholesteric color and nematic soft elasticity—making it a fundamental contribution to both fields. 1 As might be expected, this fundamentally new combination leads directly to several new observations and opportunities: (1) Soft elasticity enables a new fabrication strategy for CLCE fibers with an overall director—namely mechanical programming via inflation/force followed by dynamic boronic ester bond exchange. This strategy allows us to make a suite of fibers with different overall orientations, including circumferential overall alignment, which has been a longstanding challenge in the CLCE fiber field. (2) The resulting fibers show a range of unusual deformation pathways upon inflation, including twisting, anomalous contraction, and instabilities. These are understood as a consequence of the soft elasticity, and connect us with an extensive literature on such instabilities/deformations in nematic elastomer balloons. Moreover, we not only connect CLCEs with this nematic soft-elastic literature; we actually significantly exceed the nematic literature in both theory and observation—including the first observation of a sudden twisting instability under oblique alignment, and the first presentation of the corresponding mechanical theory. (3) Finally, all these complex deformation pathways are accompanied by color changes that we are also able to predict and understand. Our system thus delivers true multifunctionality with original color, color-pathway and deformation pathway all subject to design. Furthermore, we can imagine the same level of multi-effect design being applied to any CLCE structure, not just the fibers studied here. Our work is thus the foundation for a new generation of CLCE experiments and devices. We believe these three factors clearly bring our work to the level of Nature Communications. Comment 1:My comments are as below: My major concern is the authors’ claim that the reactive mesogens rotate from a longitudinal (or polydomain) alignment to a circumferential alignment during pneumatic inflation. In my view, this is overstated. The schematic illustration in this paper implicitly assumes the bistability of reactive mesogens, i.e., mesogens adopt either longitudinal or circumferential alignment. However, there is no basis to think that such discrete states can be energetically stable, nor that inflation alone can drive a well-defined transition between them. I would agree with a partial director rotation, but it seems too dramatic to assert that the mesogens can undergo a definite 90° rotation while 2 being chemically crosslinked. If dynamic bond exchange plays any role (which I presume is unlikely), the reported cyclability would be difficult to reconcile. Reply 1: We thank the reviewer for raising this concern. Ultimately, the existence of large director rotations, and their effect on the CLCEs' mechanics, are the key concepts in the paper—and, in our view, the fact the reviewer doubts their possibility underlines the novelty and importance of our work. We first highlight that such large (90-degree) rotations of the director are a commonplace and accepted feature of nematic elastomers. This has been understood since the pioneering work of Warner and Finkelmann. Below we show a classic figure (Figure R1) showing director rotation angle (left) and stress (right) against stretch during a tensile stretching experiment. In particular, we highlight how the director does not just asymptote towards 90-degree rotation at large stretch, but rather reaches the full 90 degrees at a large but finite stretch. Figure R1. The director rotation angle θ (λ) in each domain (left) and an associated stress-strain curve showing the soft-elasticity plateau in a sample of LCE with flexible tri-functional cross-links (right) (J. Phys.: Condens. Matter 1999, 11, R239). From a theoretical perspective this behavior is very well predicted by the now well accepted non-ideal neo-classical energy model for nematic elastomers, which was originally derived (from microscopic statistical mechanics) by Warner, and which was used to create the theory lines on the above plots. The energy density if given by (also shown in the main text) 1 W(F, n ) = min[ µTr(FT𝓵-1(n)F𝓵(n ) + αF(I – n n )FTnn)], 0 2 0 0 0 n where ℓ(n) ≡ r-1/3(I + (r − 1)nn) 3 Moving beyond tensile testing, there is also a more modern literature on the inflation of cylindrical nematic elastomer balloons. Inflation is not the same as tensile testing, as it involves a biaxial stress state rather than a uniaxial one. However, the fundamentals of force balance require that the circumferential stress is twice the longitudinal stress, and the above energy still predicts director rotation from longitudinal to circumferential. This conclusion has been observed experimentally (J. Mech. Phys. Solids 2020, 142, 104013), explored theoretically (J. Appl. Phys. 2021, 129, 114701; EPL, 2020, 132, 36001) and observed in finite elements (A.E.H. Chehade, B. Shen, C.M. Yakaki, T.D. Nguyen, S. Govindjee, “Finite element modeling of viscoelastic liquid crystal elastomers,” UCB/SEMM- 2023/01, University of California Berkeley (2023). https://escholarship.org/uc/item/64d1w46t) (Figure R2). Additionally, even traditional isotropic balloons often show the classic ballooning instability under pressure-controlled inflation, leading to a jump in volume/strain at a critical pressure. In the context of longitudinal nematic elastomer balloons, it has been observed (J. Mech. Phys. Solids 2020, 142, 104013) and explained (EPL, 2020, 132, 36001) that a similar instability can result in a sudden rotation of the director from longitudinal to circumferential, unlike the continuous rotation seen in tensile testing. 4 Figure R2. Snapshots of the (unscaled deformation) of the LCE balloon with director field and contours of axial motion at pressures of 0, 10, 20, 30, 40, 50, 60, and 70 kPa, top to bottom (A.E.H. Chehade, B. Shen, C.M. Yakaki, T.D. Nguyen, 5 S. Govindjee, “Finite element modeling of viscoelastic liquid crystal elastomers,” UCB/SEMM-2023/01, University of California Berkeley (2023). https://escholarship.org/uc/item/64d1w46t). We hope these points clarify that the mesogens (directors) really can and do rotate by 90 degrees in nematic elastomers, even after crosslinking. Is the same expected in cholesteric LCEs? Cholesteric and nematic liquids differ in their free-energy by the addition of a source term q in their Frank-elastic twisting energy, 0 (K (n·curl(n))2 > (K (n·curl(n) + q )2, which makes the helical structure the 2 2 0 energy minimum. However, after crosslinking, such Frank terms are always negligible compared to polymer elasticity, so the appropriate free energy is exactly the same as that shown above, only with the director n following the helical 0 profile of the cholesteric that was present at crosslinking. This view is also well- established (e.g., Eqns. 1, 2, and 3 of PRE 2002, 65, 056614 and Ch 9 of the classic book “Liquid Crystal Elastomers, Clarendon Press, Oxford, 2003” by M. Warner, E. M. Terentjev), and the resulting theory of CLCEs is the standard way of explaining their blue-shits under strain (pitch follows deformation exactly because rubber elasticity dominates Frank energy). The theory also substantially predicts that the original helical director will indeed rotate towards an imposed uniaxial strain, as seen in the graph below (Figure R3), which shows director angle vs z evolving from a linear helix at no stretch (λ = 1) to a much more uniform state with θ ≈ 0 by λ = 1.25. Figure R3. Dependence of the orientation of the director on distance along the pitch axis for helices subjected to several different x strains of magnitude λ (PRE 6 2002, 65, 056614). We hope the above observations leave no doubt that very large director rotation is possible in nematic and cholesteric LCEs under strain, and that in cylindrical balloons, we expect rotation towards the circumferential direction. Of course, reorientation is not perfect—as seen in the λ = 1.25 line above, there is a residual periodic wobble around the θ = 0 uniform state (in the figure, about ±22 degrees, though it falls further with increasing stretch). The key innovation in our manuscript is the use of the dynamic bonds to make such strained cholesteric states (with overall alignment and a wobble) the energy minima of the network—the character of the states themselves follows the conventional wisdom in the field for strained cholesterics. In addition to these background observations, we report numerous experimental findings that support the existence of strong reorientation (and overall alignment) in our samples, including the rotation towards circumferential during pneumatic inflation. (i) Figure 3c shows the POM image of a longitudinally aligned CLCE hollow fiber. The sample appeared completely dark when its long axis was parallel to one of the polarizers, and became bright when rotated 45° relative to the polarizer. This is the standard optical signature of strong nematic-like alignment. Figure (4c) displays similar optical data for a circumferentially aligned sample. (ii) The nature of POM means that such microscopy cannot actually distinguish, longitudinal and circumferential alignment, but this remaining ambiguity is removed by the XRD data (Figures 3d(ii) and 4d), which unambiguously shows longitudinal and circumferential alignment respectively, and quantifies that both have strong alignment (orientation degree of 0.63 for the longitudinally aligned sample and 0.60 for circumferential). We note that partial rotation towards, say, circumferential, would not result in the POM dark directions being at 0/90, nor in the XRD arc being centered at 0/90. Finally, we note that the deformation pathways of the fibers under inflation provides further very compelling evidence for full director rotation. In longitudinal balloons, we first observe anomalous shortening during inflation, which is associated with rotation towards circumferential, followed by a more conventional lengthening after rotation is complete. This very unusual behavior is predicted by our theory (and prior theories/experiments/numerics in nematic 7 balloons), where it is directly caused by rotation to circumferential (which drives shortening) followed by the completion of rotation, after which we observe conventional balloon lengthening. We have revised the relevant statements in the revised main text (page 9 and 17). Comment 2: Figure 4d, WAXS data, is presented as the key data supporting the author’s claim that circumferential alignment is observed after inflation. This is the part where my reservation arises, because the X-ray image is rotated by 90° relative to other WAXS patterns such as Figure 3d (I can tell this by the position of the beam stopper). This is very critical. Reply 2: Thanks for the reviewer's professional comments. During the testing process, to ensure the accuracy of the experimental results, the longitudinally aligned sample and the circumferentially aligned sample were oriented at a 90° difference relative to the instrument. The former was placed vertically, while the latter was placed horizontally, ensuring that the alignment direction for both samples was vertical relative to the instrument. This kept the position of the X-ray image consistent relative to the beam stopper. The reason we did not place both samples at the same orientation during testing— which would have resulted in a 90° difference in their alignment directions and X- ray images—was exactly the presence of the beam stopper. The beam stopper causes the intensity in the azimuthal scan to be very low at its position. If the circumferentially aligned sample had also been placed vertically, the position of one of its diffraction arcs would have coincided with the beam stopper. This would have caused an interruption in the curve precisely at the peak positions (90° or 270°), adversely affecting the accuracy of the orientation degree calculation. By adjusting the orientation of the two samples during testing, we effectively avoided this issue. This ensured that the interruption caused by the beam stopper appeared at the trough of the curve (around 180°), thereby minimizing its impact on the calculation. This can be observed in the azimuthal scan intensity curve. We appreciate that this subtlety in how the data was collected could lead to a question about whether it is accurately reported, but we have double and triple checked this, and are certain that it was. In addition to our experimental records, we note that the subsequent inflation behavior of the balloons, and their thermal actuation both accord with our reported XRD data, and would be very hard to explain if the data 8 was in fact flipped by 90 degrees. To avoid further confusion, we have explained the XRD process clearly in the caption of Figure 3d in the revised main text (page 20) and rotated the XRD pattern in Figure 4d so that the position of the beam stopper matches that in Figure 3d to avoid any misunderstanding. Comment 3: I strongly recommend that the authors perform in-situ experiments to directly observe the alignment rotation during inflation. Reply 3: Thanks for the reviewer’s professional comments. This is an excellent suggestion to make our experimental results more convincing. In this work, XRD was the most direct method to in situ observe the alignment rotation during inflation. For a longitudinally aligned CLCE hollow fiber, as the pressure increased, the direction of the pair of diffraction arcs in the X-ray image was expected to rotate by 90° at the critical pressure, thereby demonstrating the formation of circumferential alignment. However, in practice, the XRD equipment required high voltage and had to be fully enclosed, making it impossible to place the sample—which was connected to tubing and an air pump—inside the chamber to perform in-situ experiments. Additionally, POM images can reflect the alignment of the CLCE hollow fiber through birefringence. When the longitudinally aligned CLCE hollow fiber was oriented at 45° to the crossed polarizers, the sample appeared bright, as shown in Figure 3c. When the LC mesogens were reoriented to the circumferential direction via inflation, the sample also appeared bright at the 45° position relative to the crossed polarizers, as shown in Figure 4c. Based on this, we could predict that during the rotation of the mesogens from longitudinal to circumferential direction, the POM image would transition from bright to dark and back to bright. However, this process was accompanied by changes in the sample shape, which caused the microscope to lose focus. Moreover, as this process was continuous, it was not feasible to adjust the focus in real time during pneumatic actuation, making this in situ observation impractical. Fortunately, we were able to demonstrate the rotation of LC mesogens by in situ observing the changes in the circular polarization selectivity of the CLCE hollow fiber during inflation. This is based on the dependence of the circular polarization selectivity of CLCEs on the orientation of their mesogens. For example, the 9 literature (Adv. Funct. Mater. 2023, 33, 2304506) shows, in Figure R4, that when a polydomain CLCE film was subjected to asymmetric stretching (uniaxial stretching), its LC mesogens rotated and tended to align along the stress direction, causing distortion of the helical structure and the disappearance of circular polarization selectivity. In contrast, after symmetric stretching (biaxial stretching), the mesogens maintained their original helical arrangement and polydomain state, thus retaining circular polarization selectivity. In our experiments, as shown in Figure R5, the initial polydomain CLCE hollow fiber exhibited circular polarization selectivity: reflection colors were observed under no polarizer (NP) and right-handed circular polarizer (RCP) conditions, while no color was seen under left-handed circular polarizer (LCP). During the inflation process, as the pressure increased, the color under NP and RCP showed no significant change. However, under LCP, the color of the CLCE hollow fiber gradually became visible. Corresponding reflection spectra (Figure R6) further confirmed this result. This in situ observation indicated that the CLCE hollow fiber progressively lost its circular polarization selectivity as the pressure increased, suggesting the mesogens developed directional alignment. This is consistent with our statement in the text: “Although the polydomain CLCE hollow fiber exhibited overall mechanical isotropy, the hollow fiber structure experienced doubled circumferential (hoop) stress compared with longitudinal stress under the same pressure, leading to director reorientation toward the circumferential direction…” We thank the reviewer again for this suggestion, which has enriched our discussion on the alignment rotation during inflation. 10 Figure R4. Helical structure changes and photographs through RCP and LCP of CLCEs under a,b) asymmetric uniaxial and c,d) symmetric biaxial stretching in the literature (Adv. Funct. Mater. 2023, 33, 2304506). Figure R5. Images of a red polydomain CLCE hollow fiber inflated at different pressures observed through NP, RCP, and LCP. The faint color at 120 kPa was likely due to either the thinning wall thickness making the sample more transparent, or the reflected wavelength approaching the ultraviolet region. 11 Figure R6. Reflection spectra of the red polydomain CLCE hollow fiber inflated at different pressures with NP, RCP and LCP, respectively. We have added above results and discussion into the revised main text (page 7) and Supporting Information as Figure S3 and S4. Comment 4: The authors define that the Δpc for the CLCEs with a longitudinal alignment is 80 kPa, but I disagree. The ∆pc appears to be rather 60 kPa. Reply 4:Thanks for the reviewer’s careful reading and professional comments. In this work, the critical pressure Δp at which the CLCE hollow fiber began to undergo drastic deformation was defined as Δp . Our experimental observations show that no c significant deformation was observed at 60 kPa, while a clear and sudden instability occurred by 80 kPa. Based on these results, we can confirm that the instability occurs between 60 kPa and 80 kPa. We have revised the main text to make the description more accurate. We have added a more detailed discussion in the revised main text (page 12). 12 Comment 5: I disagree with the statement on page 12 line 285-288. A drastic change in the contraction is concurrent with the wavelength. I can see a linear trend from 60 kPa to 120 kPa. Reply 5: Thanks for the reviewer’s professional comments. This was very valuable for allowing us to explain the results more clearly. In our view, the blue-shift graph (Figure 3g) clearly shows two regimes. The first four points (0, 20, 40, and 60 kPa) show a first quasi-linear trend with a low gradient—i.e., a small amount of blue shift. The last three points (80, 100, and 120kPa) have a much steeper gradients, indicating much bluer shift. The switch between these two regimes is driven by the balloon instability at Δp , somewhere between 60 and 80 kPa (as above, we c agree we should not have described this trend as starting at 80, but nor does it extend back to 60). The feature that we wish to draw attention to is that it is the balloon instability itself, at Δp , coincides with the dramatic shortening of the c balloon—which suddenly almost halves in length—but this dramatic shortening is accompanied by only a mild blue-shift (about 8% wavelength shift between 60 and 80kPa, a much smaller factor than the 50% longitudinal strain), with much greater blue shift occurring afterwards, between 80 and 120kPa. This is visually very clear in Figure 3e, where the dramatic contraction is seen first, then the color starts to change. The explanation also accords well with the theory, and is the signature of the jump being driven by soft-elastic rotation—an essentially in-plane effect—rather than by thinning; this quasi-2D elasticity is a common feature of nematic semi-soft elasticity, but quite different to normal rubber elasticity. We have added above results and discussion to the revised main text (page 12 and 13). Comment 6: I disagree with the statement on page 9 line 217-218. The agreement between experimental results and theoretical simulations is more than a little disappointing. I think the theory is quite off from reality (Figure 2e & Figure 2g). Figure 2g has obviously a linear trend. Reply 6: We thank the reviewer for raising this question. We have removed the word “little,” and the manuscript now simply states the quantitative agreement “is somewhat disappointing”. Although we agree that the fit is indeed disappointing for this case, we would also like to emphasize that the theory is still getting a lot of things 13 right—we are correctly predicting non-monotonic and small length change, monotonic and large diameter change, and a large monotonic blue shift. Furthermore, the magnitudes of the blue shift and the diameter change are very close to reality, but the precise form of the curves and, most of all, the magnitude of the length change, are not correct. We also emphasize that the deformation path of this balloon is actually comparatively uninteresting, as it lacks the dramatic jumps and twists provided by longitudinal and helical alignment—and the theory works much better in these more interesting and more unexpected cases. Given how few fitting parameters are in the theory, getting such a good fit across so many different experiments is, overall, not disappointing at all, even though in this particular case we would certainly have preferred to do better. Of course, it is natural to ask why we are not getting a better fit for the polydomain case. The answer is two-fold. Firstly, it is also commonly observed that the nematic elastic energy we use is much more accurate for semi-soft (director rotating) modes of deformation than for “hard” modes of deformation, where effects such as changes in magnitude of alignment can also be important. The polydomain contains the full helical director, sampling all planar directors. This means that there are no fully soft elastic modes available—as the balloon inflates, some directors that started longitudinal can rotate to circumferential—which would alone be a soft deformation—but they are mechanically connected to further regions that started circumferential, and cannot rotate any further. This explains the comparatively stiff response of the balloon, and its lack of interesting soft-elastic instabilities, but also explains the poorer performance of the model in this case—it is optimized for the cases where soft elasticity is more important, which are in fact also the more interesting cases. Additionally, in this case, there is also substantial complexity arising from the fact that the in-plane structure is an in-plane polydomain—all the helices have the same pitch axis, but moving in the plane, one has a polydomain structure. Even in the simpler nematic case, the effective bulk constitutive law of such polydomain structures is very hard to figure out, as it depends on the precise configuration of the domains, and the extent to which they do or do not cooperate during deformation. Indeed, experimentally polydomain nematics can vary from very stiff to almost perfectly soft-elastic depending on their crosslinking history (Macromolecules 2009, 42, 4084), and there is actually no widely accepted constitutive law for modeling their 14 mechanical response—with the best available treatment being upper and lower bounds (PRL 2009, 103, 037802). In this context, the partial success of our theory for the polydomain case might actually be regarded as surprisingly good! We have revised the corresponding description in the revised main text (page 9). Comment 7: How do the helical structures behave as longitudinal or circumferential alignment occur? Detailed discussion is required, possibly based on experimental data. Reply 7: We thank the reviewer for raising this question. As discussed in Comment 1, the programmed longitudinal or circumferential alignment is a residual periodic wobble around the longitudinal or circumferential uniform state, across the thickness direction (Figure R4). The experimental realization is the following. Firstly, as previously reported and shown in Figure R5, a polydomain CLCE exhibits circular polarization selectivity. When subjected to asymmetric forces, the LC mesogens of the CLCE tend to align in the direction of the applied force, which unwinds the helical structure and results in the loss of chiral photonic selectivity. The helical structure becomes distorted in plane but remains periodic through the thickness, with a shorter pitch due to helix compression accompanying the stretching as a result of volume conservation. On the other hand, symmetric forces maintain the inherent helical structure of the CLCE, causing only pitch contraction, and the CLCE continues to reflect circularly polarized light. Therefore, we can investigate how the helical structures behave by observing changes in the circular polarization selectivity of the CLCE hollow fiber after alignment. (1) Longitudinal alignment was achieved by stretching a polydomain CLCE hollow fiber followed by thermal programming. The experimental results in Figure R7 (the photographs at 0 kPa) show that the longitudinally aligned CLCE hollow fiber exhibited distinct reflection colors under NP, RCP, and LCP, indicating a loss of circular polarization selectivity. This suggests the helical structure became distorted during stretching but retained its periodic nature. Reflection spectra in Figure R8 further confirmed this. (2) Circumferential alignment was formed by inducing mesogen reorientation toward the circumferential direction during pneumatic actuation. For example, Figure R5 shows the inflation process of a polydomain CLCE hollow fiber. In its initial state, reflection color was observed under NP and RCP, but not under LCP, 15 indicating circular polarization selectivity. During inflation, as pressure increased, the color under NP and RCP showed no significant change, but color gradually appeared under LCP. This indicated a gradual loss of circular polarization selectivity and the formation of a distorted helical structure; the blue shift in color also indicated a reduction in pitch. Corresponding reflection spectra are shown in Figure R6. Figure R7 shows the inflation process of a longitudinally aligned CLCE hollow fiber. At the critical pressure—which signifies the formation of circumferential alignment—the CLCE hollow fiber exhibited reflection colors under both LCP and RCP, indicating the helical structure was in a distorted state. According to the reflection spectra (Figure R8), the reflection wavelength blue- shifted, confirming a pitch reduction. In summary, by observing the circular polarization selectivity of CLCE hollow fibers with longitudinal or circumferential alignment, we concluded that the helical structure in both cases was distorted but remained periodic. Figure R7. Images of a red CLCE hollow fiber with longitudinal alignment inflated at different pressures observed through NP, RCP, and LCP, respectively. 16 Figure R8. Reflection spectra of the red CLCE hollow fiber with longitudinal alignment inflated at different pressures with NP, RCP, and LCP, respectively. After the programming of alignment, the director rotation is governed by the non- ideal neo-classical energy model (see Reply 1 and the main text). We have added above results and discussion into the revised main text (page 13) and Supporting Information as Figure S9 and S10. Comment 8: The degree of alignment in CLCEs does seem to have a distinct impact on anisotropic behaviors of CLCEs during pneumatic actuation. It determines the range of pressures that the CLCEs can resist, benefited from the anisotropic nematic ordering. I think that though it is narrow, the CLCEs with polydomains also seemingly have that persistent (plateau) pressure range, from 0 to 20 kPa. The correlation between the alignment and the anisotropic behaviors of CLCEs is indeed new knowledge that this work brings; however, I believe that this finding is not sufficiently novel or unprecedented to warrant the publication in Nature Communications. Reply 8: Thanks for the reviewer’s professional comments. In our view, our key finding is that imparting overall alignment to CLCEs enriches their mechanics with soft- elasticity (and rotation of this overall alignment) and other forms of anisotropy. As the reviewer comments, even the polydomain CLCE (that lacks overall alignment) do also show some mechanical richness, including a threshold for director longitudinal strain (though not hoop strain or blue shift) at about 20 kPa, and a non-monotonic longitudinal strain as inflation proceeds. These effects doubtless also relate to director rotation in the helices of the polydomain, but they are strongly suppressed by the fact that there is no overall alignment, so regions with favorable alignment and director rotation must always compromise with others that do not. In contrast, it is the longitudinally and helically aligned fibers that are able to access pure semi-soft modes, in which the overall director rotates towards circumferential. These global semi-soft modes enable much higher strains at lower stresses (longitudinal strains of ~50% rather than ~15%), result in dramatic subcritical jumps in balloon configuration, and, in the helical case, also result in dramatic twisting of the balloon. All these effects (large longitudinal contractions, jumps, twists) are absent in the polydomain case, and demonstrate the added richness achieved by having an overall alignment. We hope we have convinced the reviewer that this strategy—the mechanics of CLCEs with overall alignment—is a rich topic, and that, as the foundational study in the area, our paper is indeed worthy of publication in Nature Communications. We have added above discussion into the revised main text (page 8). Comment 9: There are many recent works related to hollow CLCE fibers (e.g. Adv. Mater. 2025, 37, 2504461; Adv. Sci. 2025, 12, e04487). I think that relevant work should be well acknowledged and properly compared with the current work in the 18 introduction. In particular, while the deswelling-assisted template method in this work seems the identical method used in Adv. Sci. 2025, 12, e04487, the authors did not properly mention the prior work. Reply 9: Thanks for the reviewer’s professional comments. In our initial submission, we had already acknowledged the articles mentioned above, citing them in the Introduction section as Reference 19 (Adv. Sci. 2025, 12, e04487) and Reference 35 (Adv. Mater. 2025, 37, 2504461). A more detailed comparison is provided below: (1) Regarding Reference 19 (Adv. Sci. 2025, 12, e04487), in terms of fabrication, although both studies utilized the deswelling-assisted template method to prepare CLCE hollow fibers, this method could only yield polydomain structures, which is not the key claim of our article. In our work, we developed a novel method to fabricate programmed CLCE hollow fibers with longitudinal, circumferential, and twisted alignments by integrating dynamic covalent bonds with mechanical force/pneumatic pressure-induced LC mesogen orientation. This alignment technique represents a breakthrough that enables previously unattainable alignments, laying the foundation for achieving multimodal pneumatic actuation. This could not be accomplished using the deswelling-assisted template method alone. (2) Reference 35 (Adv. Mater. 2025, 37, 2504461) studied the mechanochromic behavior of CLCE tubes under different stimuli, including stretching, inflation, and bent tube inflation. The study focused solely on color changes resulting from thickness variation and did not involve actuation deformation. In contrast, our work achieved multimodal actuation with synchronous color adaptation of CLCE hollow fibers under a single pneumatic actuation mode by utilizing diverse programmed alignments, based on mechanical anisotropy and soft elasticity. This enables CLCEs to not only work as single-function photonic devices but also possess mechanical output capabilities. (3) In addition to the two articles mentioned by the reviewer, we also cited another paper on hollow-structure CLCEs as Reference 36 (Adv. Funct. Mater. 2024, 35, 2413965). This work also only investigated the color changes of CLCEs under different pressures. Overall, compared with recent work on hollow CLCE fibers, whether it is the 19 preparation of hollow CLCE fibers or the investigation of color-changing behavior under inflation or mechanical stretching, our work was capable of achieving these. However, the programming of complex alignments in CLCE hollow fibers and the multimodal responses under pneumatic actuation were not achievable in previous work. Moreover, those three articles were limited to color changes induced by stimulus-driven thickness variation, whereas we introduced mechanical anisotropy and soft elasticity to explore new behaviors arising from force-induced LC mesogen rotation, bringing innovation at the fundamental mechanism level. Notably, two of those references were published in 2025, which fully highlights the novelty of our work and its position at the forefront of the field. We have added appropriate and relevant descriptions in the introduction of the revised manuscript (page 2). Comment 10:The authors should use clear and straightforward terminology throughout the manuscript. For example, on page 1 line 21, nematic phases are not parents of cholesteric phases (i.e., a cholesteric phase is not a subphase of nematic phase). Reply 10: We thank the reviewer for reminding us to revise the terminology, which makes the presentation in the manuscript more accurate. The sentence now reads: “However, the helical structure of CLCEs averages out the exceptional anisotropy and soft elasticity of the nematic phase, leaving little scope for also using the director orientation to program their thermal or mechanical actuation.” We have changed this terminology in the revised manuscript (page 1). Reviewer #2 Comments: This work presents a significant advancement in the field of soft smart materials by developing programmable cholesteric liquid crystal elastomer (CLCE) hollow fibers with multimodal pneumatic actuation and synchronous color changes. The authors successfully combine dynamic covalent chemistry, director programming, and pneumatic control to achieve complex deformation modes, which are coupled with dynamic structural color shifts. To understand these phenomena theoretically, the authors develop a unified theoretical model using non-ideal LCE energy and solve a ballooning instability problem. The theoretical results agree with the experiments well, revealing that the instability involving director rotation plays a significant role. This work sets a new benchmark for the field of adaptive color- 20 changing and intelligent actuation systems. The authors successfully combine dynamic covalent chemistry, director programming, and pneumatic control to achieve complex deformation modes, which are coupled with dynamic structural color shifts. To understand these phenomena theoretically, the authors develop a unified theoretical model using non-ideal LCE energy and solve a ballooning instability problem. The theoretical results agree with the experiments well, revealing that the instability involving director rotation plays a significant role. This work sets a new benchmark for the field of adaptive color-changing and intelligent actuation systems. Overall, the paper is well-structured and written. The methodology is robust, the results are compelling, and the theoretical framework provides valuable physical insight. The topic and the quality match the requirements of Nature Communications. I highly recommend its publication. Reply: We truly appreciate that the reviewer acknowledged our work and believed its topic and quality match the requirements of Nature Communications. We hope that the fundamental innovations and significant technological advances achieved in this work will go beyond conventional approaches to color-changing CLCEs, paving the way for future developments in soft actuators and adaptive systems. Comment 1: Here are some comments for authors to consider and further improve the work. During the programming process, the CLCE hollow fiber needs to undergo stretching, twisting, or pneumatic expansion to align the liquid crystal mesogens. Providing the mechanical properties of the CLCE hollow fiber before programming is crucial for completing the experimental information. Reply 1: Thanks for the reviewer’s professional comment. In this work, before programming, the CLCE hollow fiber was in a polydomain state. Figure R9 shows the stress-strain curve of the polydomain CLCE sample. Its fracture strain was around 470%, with a corresponding stress of 2.0 MPa. The calculated Young's modulus was 0.86 MPa. Figure R9. The stress-strain curve of the polydomain CLCE sample. 21 We have added above results and discussion into the revised Supporting Information as Figure S5. Comment 2: For the polydomain sample, which lacks mechanical anisotropy and directional orientation, why does the CLCE hollow fiber initially undergo axial contraction rather than expansion upon inflation? Reply 2: Thanks for the reviewer's professional comment, which helps us to further elaborate on the pneumatic actuation mechanism of the polydomain CLCE hollow fiber. Although the polydomain sample was mechanically isotropic, the internal stress distribution under inflation is anisotropic. In a cylindrical structure under the same pressure, the circumferential (hoop) stress is always twice the longitudinal stress—this is a feature of stress balance, independent of the material in question. Of course, both stresses are tensile, and in a conventional balloon, this does result in it getting longer and fatter during inflation. In a nematic elastomer with longitudinal alignment, this stress distribution rotates the director to circumferential in a perfect soft mode which actually shortens the balloon—this is the so-called “anomalous inflation” of nematic balloons. After the director is circumferential, the “anomalous” phase finishes, and the balloon starts to elongate classically. In contrast, in a circumferential nematic balloon, there is never any director rotation, so inflation proceeds essentially classically throughout, elongating the balloon. In the full helix present in a polydomain, we have both these cases (and every intermediate angle) present, but they must all deform in the same way, so the balloon must reach a compromise between the longitudinal case (shorten then lengthen) and the circumferential case (lengthen). The result is that the balloon does shorten then lengthen, but markedly less than with longitudinal alignment, and at much higher pressure, since the originally circumferential parts are not deforming in a soft mode. We have added clear explanations into the revised main text (page 8). Comment 3: The current work focuses on pneumatic actuation, which requires a physical connection to an air pump. Is it possible to achieve wireless or remote actuation to free the system from such constraints? Reply 3: Thanks for the reviewer's professional question, which provides important guidance for the future development of pneumatic CLCE materials. The physical 22 connection to an air pump does impose certain constraints on the actuation process. To address this issue, one potential solution could be to incorporate phase transition materials (Sci. Robot. 2020, 5, eaaz4239; Nat. Commun. 2025, 16, 3920) or chemical reactants (Adv. Mater. 2024, 36, 2403954) into the CLCE cavity. By increasing the temperature to induce a phase transition or triggering chemical reactions to generate gas, the internal pressure could be increased for actuation. Such strategies have already been reported in some studies on pneumatic actuation. We believe that integrating these approaches with the CLCE system could contribute to pneumatic miniaturization and enhance applicability for untethered applications in the future. We have cited the aforementioned literature as reference 66, 67, and 68 to provide support for our outlook. Comment 4:The authors have developed a method combining dynamic covalent bonds with mechanical/pneumatic fields to achieve various alignment programming of CLCE hollow fibers. Conceptually and practically, what are the main breakthroughs and innovations of this strategy compared to traditional alignment methods for CLCE or LCE fibers? Reply 4: We thank the reviewer for raising this question. First, conceptually, this work proposes a new alignment paradigm. Traditional methods rely on mechanical stretching, shear, or external fields, which are limited in the types of alignment they can produce within a fiber geometry. This strategy introduces a novel concept: using pneumatic pressure combined with dynamic covalent chemistry as a powerful and versatile tool for programming alignment, moving beyond the constraints of conventional techniques. Second, in practical terms, due to the limitations of previous alignment techniques, achieving circumferential alignment in a fiber had not been realized. By combining dynamic covalent bonds with mechanical/pneumatic fields, we successfully achieved circumferential alignment in CLCE hollow fibers. This represents an unprecedented breakthrough in the field of CLCEs, and even LCEs more broadly, as it had never been accomplished before. This strategy greatly expands the design space for CLCEs and significantly 23 broadens the potential for creating mechanically anisotropic and soft-elasticity- based devices. We have added corresponding discussion to the revised manuscript (page 27 and 28). Comment 5: We’ve seen some work on the ballooning instability of LCE balloons. Please clarify what are the differences between the inflation of an LCE balloon and a CLCE balloon. Reply 5: We thank the reviewer for raising this question. Given the diversity of approaches that have been explored for nematic LCE balloons, it is a little complicated to describe exactly how it all relates to our work. The first paper (J. Mech. Phys. Solids 2020, 142, 104013) is an experimental and theoretical study of longitudinal nematic balloons. However, the paper is rooted in the ideal LCE energy (α = 0) where soft modes cost no energy at all, meaning they predict full rotation to circumferential at zero pressure. To counter this, they then consider balloons with a weight hanging on the end, which keeps the director longitudinal until a pressure threshold, at which point it jumps to circumferential. They observe and predict this instability, with the weight. The paper (Thin Wall Struct. 2022, 170, 108621) does a similar theory analysis of a helical balloon with a weight, leading to a prediction of a sub-critical twisting instability, but with no corresponding experimental observation. In contrast, the papers (EPL 2020, 132, 36001; J. Appl. Phys. 2021, 129, 114701) provide a theoretical analysis of longitudinal balloons with non-ideality, such that finite pressure is required to trigger ballooning, even without a weight. These papers clarify that non-ideal nematic balloons are still expected to show a sub-critical rotation instability, but there are no corresponding experiments. In our work, we use the classic nematic energy, with non-ideality, but also with a director profile that oscillates around the overall director in the thickness direction, reflecting the cholesteric character. Without this undulation, our theoretical model would be essentially the same as that reported for the longitudinal case (EPL 2020, 132, 36001; J. Appl. Phys. 2021, 129, 114701). This undulation is thus the key theoretical difference between the aligned CLCE balloons and pure nematic ones. The overall effect of the undulation is qualitatively similar to non-ideality, in that it also provides an energy penalty for rotation of the overall alignment, as the soft 24 modes of the different parts of the undulation do not exactly match, so some degree of compromise is required. This means that the instabilities of aligned CLCE balloons are not fundamentally different to those in nematic, but are delayed by this additional anchoring mechanism. In reality, this CLCE mechanism seems to be rather stronger than the true material non-ideality. As a result, our balloons show instabilities at small but finite pressures, so that we are able to observe both inflation before and after the instability, with no need to apply a weight to unnaturally delay the instability (as was done in, e.g., J. Mech. Phys. Solids 2020, 142, 104013). We also note that, compared to the existing nematic balloon literature, we are providing a first treatment of circumferential and helical balloons with the non- ideal formulation (rather than weights), and the first corresponding experimental observations. We also note that the “undulation” that separates CLCE membranes from pure nematics exists on a spectrum, from the fully helical cases of polydomain CLCE (which is mechanically isotropic) to the fully aligned case (which is just a nematic). Thus, the undulation idea also allows us to capture the key mechanics of the polydomain case within the same theory, for which there is no nematic counterpart. The corresponding content are presented on page 13 of the revised manuscript. Comment 6:In Figure 3 (longitudinal alignment), the wavelength keeps almost unchanged in a relatively large range of inflation. What is the mechanism behind this phenomenon? Could this point be used to design an actuator or some other applications? Reply 6: The mechanism here is that the balloon is deforming in a pure soft mode, wherein the director rotates from longitudinal to circumferential. The soft mode results in the polymer conformation ellipsoid rotating from longitudinal to circumferential, driving longitudinal contraction and circumferential extension, but with almost no change in thickness and hence no change in color. This two-dimensional character of soft modes is familiar in nematic elastomers under tensile tests, but unfamiliar in this context. It certainly highlights how suitable design of the overall orientation in CLCE balloons can give a degree of independent control over strain vs color- shift. We also note that the above cartoon is not perfect—there is some thinning, 25 and some blue shift, during the first part of actuation. Again, this is familiar from non-ideal nematic LCEs, where one does indeed see thinning prior to the onset of director rotation (the so-called semi-soft threshold), but not during director rotation. In the CLCE the residual undulation again acts like an additional non- ideality, enhancing this effect, and in future work, we plan like to study whether we can use the degree of undulation to tune this effect. The distinct “plateau‑then‑jump” optical response offers unique opportunities for designing functional devices. (1) Threshold-type optical sensors. This non- monotonic effect can be used to design sensors that visually indicate when stress or stretch exceeds a set threshold—for example, a sensor that begins to change color precisely upon crossing the critical stress/stretch point. (2) Multi-stage soft actuators. In the low-pressure range, both the optical signal (structural color) and dimensions remain stable. Once the critical pressure is exceeded, a synchronous abrupt change in optical signal (color switching) and a rapid mechanical response (e.g., contraction) are triggered, enabling coordinated optical-mechanical dual- mode actuation. (3) Dynamic camouflage and information encryption. By programming CLCE fibers with different alignments, multi-mode optical responses can be achieved. Longitudinally aligned devices can “hide” color changes below the critical pressure, then suddenly display color above it. When combined with the gradual color shifts of polydomain devices, pressure-dependent dynamic pattern systems can be constructed for adaptive camouflage or encrypted information display. The relevant discussions are presented on page 14 and 15 in the revised manuscript. Reviewer #3 Comments: This was a very entertaining paper, and I found the results interesting. Achieving the alignments in the LC balloons was noteworthy, and the study was quite thoroughly done. Reply: We are sincerely grateful for the reviewer's positive assessment of our work. We are particularly encouraged by the recognition of our results on alignment control in LC balloons. This technique expands the design space for CLCEs and even LCEs, providing a key foundation for leveraging mechanical anisotropy and soft elasticity, as well as for enabling multimodal actuation. This study sets a new benchmark for what CLCEs can achieve and opens avenues for their use in 26 advanced technological contexts. We hope this work will draw attention to and inspire further research in the field of LCE materials. Comment 1: I have few comments: Figure 1g. I suggest the authors state in the legend what the arrows represent. It is a bit of a difficult story, and it would help a lot if the authors distinctly state that the arrows delineate the mesogen alignment and not, for example, the helical axes. Reply 1: Thanks for the reviewer's professional suggestion, which helped us to provide a clearer schematic diagram of the multimodal actuation. We have added an arrow icon at the bottom of Figure 1g, with the text \"alignment\" on the right to indicate its meaning, as shown in the illustration below. Figure R10. Morphology and working principle of CLCE hollow fiber. 27 Comment 2: This may be a naïve question, but I ask it anyway. If the mesogens in the polymerized film are forced to rotate towards the longitudinal direction, I assume this force is felt all through the depth of the helix. As the individual mesogens collectively rotate along the longitudinal, does this not affect the reflection band? I would assume this lowers the pitch, resulting in a red shift. However, the thickness decreases, tightening the pitch. Which feature wins out under extreme extension? Reply 2: We thank the reviewer for the comment, which helps clarify the thickness and color change upon director rotation. First of all, ideally the pure director rotation does not change the depth of the helix as well as the reflection band, since the director rotation is in-plane. Without director rotation, a uniaxial stretch would lower the thickness as well as the pitch, and thus cause a blue shift. With director rotation, ideally, the in-plane director rotation would preserve the thickness. For example, in the literature (J. Phys. II France 1997, 7, 1059), it was observed both experimentally and theoretically that, ideally, the elastic energy remains zero, and the thickness of a thin film stays unchanged under uniaxial stretch within a certain range, predicted by the theory. However, in the case of CLCEs, the director field varies through the thickness. Directors located in certain regions of the thickness may already be aligned with the stretching direction, leading to a reduction in thickness under applied stretch. Thus, to achieve a quantitative understanding of the changes in thickness and color should be computed by our model. Please also see the detailed explanation in Comment 6 from reviewer 2. The relevant discussions are presented on pages 12-13 of the revised manuscript, and the corresponding literature is cited as reference 49. Comment 3: Ln 266: “while maintaining enough residual wobble alignment to preserve the structural color” Is there any estimation of the % reflection from the fibers? The only plot I see has 'relative' values. Can the authors estimate the fractional reflection? Reply 3: We appreciate the reviewer's professional question. Regarding the % reflection of the fiber, we could measure it directly using an optical fiber spectrometer without estimation. However, since the distance between the sample and the light source affects the intensity of the reflection peak, and the deformation of the sample during pneumatic actuation causes this distance to change, we used arbitrary units (a.u.) for reflectivity to ensure more accurate data representation. By strictly controlling the position of different samples, we could indeed use percentage (%) to display the reflectivity values directly. Figure R11 shows the reflection spectra 28 of the longitudinally aligned CLCE hollow fiber before and after programming. It is worth noting that although a dark reference was calibrated during testing, the inherent thickness (diameter) of the sample inevitably placed it closer to the light source than the dark reference, resulting in an increased baseline value in the curves. The fiber reflectivity is not the peak value of the curve but the difference between the peak value and the baseline. Through Lorentz fitting, the reflectivity of the fiber before and after programming was calculated to be 39% and 44%, respectively. This indicates that although stretching distorted the helical axis of the CLCE, its reflective performance was not weakened. Instead, it may have increased due to the simultaneous reflection of both left- and right-handed circularly polarized light, which is consistent with existing literatures (Nat. Mater. 2022, 21, 1441; Adv. Sci. 2023, 10, 2301414). Figure R11. Reflectance spectra of the longitudinally aligned CLCE hollow fiber before and after programming. We have added above results and discussion into the revised Supporting Information as Figure S7. We appreciate the time and consideration of the editor and reviewers. We would be happy to provide further information if needed. Yours sincerely, Zhongqiang Yang 29"}, {"round": 2, "reviewer_comments": {"reviewer_1": "Authors clarified my questions properly.", "reviewer_2": "The author has finely addressed all of the issues. Now the manuscript has been improved and can be accepted.", "reviewer_3": "I have read the author's responses to all reviewers, and I am satisfied they have made the alterations that were required of them. I still find it an interesting work and is deserving of publication."}, "author_response": ""}]

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