Regular-wrinkling tunable MXene lattice for electromagnetic interference shielding

Domain: physics
Published: 2026-01-10
Editorial outcome: major_revision

Abstract
Protecting sensitive equipment from electromagnetic radiation damage requires the development of high-performance electromagnetic interference shielding films. As the film thickness is reduced to micro/nanoscales, electromagnetic interference shielding capability generally decreases rapidly due to the weaker reflection. As a result, enhanced electromagnetic interference shielding performance in sub-μm thin films remains an unsolved challenge. Inspired by the naturally wrinkling of fruit skin, we propose a homogeneous strain strategy to achieve self-wrinkling-induced lattice-structured MXene by uniform polymer shrinkage due to dehydration. Uniform wrinkle amplitude can be tuned from 0.8 to 6 μm, which results in additional surface scattering of electromagnetic-waves and electrical conduction paths. The obtained lattice-structured films demonstrate an excellent electromagnetic interference shielding of up to 81.5 dB for a thickness of 17 μm, maintaining high electromagnetic interference shielding performance and stability after enduring various harsh testing conditions. These results demonstrate the potential of wrinkling-induced, surface regular patterns for improving the electromagnetic interference shielding performance of ultra-thin films based on conventional materials.

Introduction
The ongoing miniaturization and integration of electronic components in consumer electronics, wearable devices, and communication systems have created an urgent demand for ultra-thin electromagnetic interference (EMI) shielding films1–3. Conventional bulky EMI shielding materials have become unsuitable for compact device architectures. The ultra-thin EMI shielding film can effectively isolate EMI without significantly increasing the volume or weight of the device, thereby ensuring the integrity of high-frequency and high-speed signal transmission4,5. Furthermore, their application has expanded to extreme environments such as aerospace and polar research, where high-efficiency EMI shielding performance and reliable operation under harsh conditions are critically required6,7.

MXenes are a type of two-dimensional layered materials composed of transition metal carbides, nitrides, or carbonitrides. Their most notable characteristics are their excellent intrinsic electrical conductivity and rich surface chemistry, making them ideal candidates for constructing high-performance EMI shielding materials8,9. The EMI shielding effectiveness of MXene-based materials stems from the synergistic effects of conductive loss, polarization relaxation, and efficient internal reflection within their layered structures10,11. Although the layered structure of MXene inherently enables a certain synergy between reflection and absorption, its shielding mechanism reverts predominantly to a single, dominant surface mirror-like reflection when processed into macroscopic films12. Reducing the interlayer spacing through methods such as vacuum annealing or ion cross-linking can enhance EMI shielding performance13,14. However, the improvement remains limited due to reliance on a single mechanism of conductivity enhancement. Alternatively, introducing magnetic or dielectric components can enhance absorption through magnetic loss or interfacial polarization, but this often comes at the cost of increased material thickness15,16. Therefore, achieving further improvement in EMI shielding performance without increasing the thickness of MXene remains difficult.

Surface pattern structures possess significant potential for substantially enhancing EMI shielding performance. This enhancement can be achieved through mechanisms such as multiple scattering within the lattice, particularly when the feature size of the patterns is reduced to the micro or nanoscale17–19. A common physical strategy for creating wrinkled structures involves pre-stretching an elastomer, depositing a rigid material on its surface, and then releasing the pre-straint to exploit interfacial instability20–22. However, conventional fabrication methods relying on wrinkle-induced patterning often struggle to form uniform micro/nano-scale surface patterns due to inherent issues like non-uniform force application and macroscopic shrinkage23. The Turing pattern mechanism, a chemical approach based on reaction-diffusion theory, presents another effective route for constructing micro/nano-scale patterns24–26. Nevertheless, the morphology and stability of Turing patterns obtained through chemical processes are highly dependent on dynamic conditions such as reactant concentration and diffusion rates, leading to challenges in controllability and long-term stability27. Consequently, achieving uniform, stable, and tunable patterns at the micro and nanoscale, especially for MXene materials, remains a formidable challenge.

Inspired by the regular wrinkling of hierarchically structured natural organisms, we propose a strategy to achieve a uniform scaled regular-wrinkling tunable MXene lattice. The film exhibits exceptional EMI shielding performance due to the enhanced scattering of electromagnetic waves and additional conductive pathways. The lattice-structured MXene demonstrates an excellent EMI shielding of up to 81.5 dB at a thickness of 17 μm. The unique surface structure enables MXene to retain high EMI shielding performance in a variety of harsh environments, and also exhibit hydrophobicity and fast Joule-heat de-icing properties. This work demonstrates a bottom-up strategy for the preparation of EMI shielding films with micro/nanoscale regular patterns. The approach offers an avenue for the development of development in composite films for EMI shielding.

Results
Formation and physical property of lattice-structured MXene
In nature, tree-detached fruits with skins dehydrate and wrinkle when exposed to air for long periods of time (Fig. 1A). Above room temperature, the process of wrinkling is accelerated and different kinds of pattens can be achieved. Inspired by this natural phenomenon, we load a concentrated MXene solution on the polymer surface. After solvent volatilization and thermal contraction, the MXene coating shows pseudo-regular wrinkle structures on the PI surface, which is referred to as the lattice structure.

The fabricating process of latticed MXene is shown in Figs. 1B and S1. The lattice is formed in two steps. First, a high-concentration MXene solution self-assembles on the surface of the PAA film. The bonding between the MXene and PAA results in anchoring of MXene to the PAA surface (Figs. S3 and S4). The H2O solvent in the MXene solution and N, N-dimethyl-formamide (DMF) solvent in the PAA solution evaporate during drying. Under the effect of surface tension generated by solvent evaporation and the bi-directional shrinkage driving force of the polymer28,29, the MXene wrinkles on the PAA surface, with 600–800 nm amplitude height for the wrinkles (Fig. S5).

Subsequently, the MXene/PAA films is heat-treated slowly increasing the temperature from 20 to 300 °C. During the high temperature treatment process, the dehydration cyclization of the PAA lead to uniform contraction of the PI (Figs. S6 and S7), with simultaneous removal of interlayer water molecules in MXene13. As a result, the MXene coating shrinks further inward on the PI surface, with the MXene layer spacing decreasing from 1.23 to 1.08 nm (Fig. S8), and the amplitude of the lattices increases to 1–2 μm (Fig. S9). Figure 1C clearly shows that the MXene is spread over the entire PI surface with obvious wrinkles. From the top-view SEM image of the MXene/PI film, the wrinkles of MXene on PI form a regular lattice structure (Figs. 1D and S10). AFM imaging reveals the three-dimensional lattice structure of MXene on the PI surface (Fig. 1E). Thankstothe simplicity and rapidity of the adopted blade coating and heat treatment, the MXene/PI films can be easily made onto large plates with film size of 45 cm × 45 cm (Fig. S11).

The formation of a regular MXene lattice structure on the PI surface is primarily attributed to the strong hydrogen bond between MXene and PAA and the uniform dehydration thermal shrinkage during the conversion of PAA to PI30,31. The MXene patterning on the polymer surface is related to the force between the MXene and polymer. Notably, MXene does not show a similar lattice structure on any of the considered polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), poly (vinylidene fluoride) (PVDF) and glass substrates (Fig. S12). The lattice-structured MXene exhibits a superior EMI shielding performance, surpassing most previously reported works, particularly in the field of ultra-thin EMI shielding films, as shown in Figs. 1F and S13 and Table S1.

The morphology of the MXene on the PI surface is closely related to the thickness of both the polymer and MXene. The adjustable parameters of the lattice structure are amplitude, wavelength and width (Fig. S14). As shown in Fig. S14, coating the same thickness of MXene on different thickness of PAA, the shrinkage of the polymer becomes large with the increase of PAA thickness, resulting in the increase of the amplitude of MXene on the polymer surface by 0.8-6 μm. However, when the polymer thickness is above 25 μm, the MXene forms an irregular patterned morphology on the PI surface (Fig. S15 and Table S2). We selected multiple coatings on PAA to regulate the thickness of MXene, and then explored the influence of coating thickness on the patterning morphology. With the increase of coating thickness, amplitude, wavelength and width all increase (Fig. S16 and Table S3). In brief, we have prepared structurally stable patterned morphologies that can be autonomously tuned with the thickness of both the polymer and MXene.

EMI shielding mechanism and performance of lattice-structured MXene
Electrical conductivity is a critical parameter for evaluating the EMI shielding performance of MXene. Firstly, the conductivity of flat MXene on PET and lattice MXene on PI under the same preparation conditions is measured. The latticed MXene exhibited a higher conductivity of 3500 S/cm compared to 2500 S/cm for the flat MXene (Fig. S17 and Table S4). The EMI shielding performance of the lattice-structured MXene was subsequently measured and compared to results for flat MXene. As depicted in Fig. 2A, the average EMI SE (SET) of the lattice-structured MXene is 50.4 dB in the X-band (8.2–12.4 GHz), significantly higher than for the flat MXene (38.6 dB). Compared with the flat MXene, the reflection loss (SER) and absorption loss (SEA) of the latticed MXene increase by 10.3 dB and 1.7 dB (Table S5). This demonstrates that the enhanced EMI SE of the latticed MXene stems from both the improved SER due to enhanced electrical conductivity and the increased SEA resulting from the surface structures responsible for promoting diffuse reflection of electromagnetic waves. According to Fig. S18, the 1% increase in the reflection coefficient (R) indicates that the additional conductive paths introduced by the lattice structure enhance electrical conductivity. This constitutes the primary contributor to the 31% improvement in EMI SE. When the thickness of the latticed MXene is 2.8 μm, and the SET of MXene/PI film can reach 50.4 dB. (Fig. 2B).

The latticed MXene achieves excellent EMI shielding performance also in the ultrabroadband GHz frequency range, including the Ku, K and Ka bands, with average EMI SE of 50.9 dB, 51.3 dB and 53.8 dB, respectively, further broadening the potential application range of the patterned films (Fig. 2C). Compared with the MXene films prepared by vacuum filtration (MXene-VAF) and flat MXene, the lattice-structured MXene can achieve the equivalent SET values at lower MXene thickness of 2.8 μm (Figs. 2D and S19 and Table S6). The EMI SE increases from 38.6 to 81.5 dB as the thickness of latticed MXene varies from 0.7 to 17.0 μm (Figs. 2E, S20 and Table S7), revealing that the latticed MXene can be used in high-end fields.

According to the result of calculation, the EMI SE of the latticed MXene is significantly increased. This is attributed to the fact that the prominent lattice structure introduces additional conductive paths in the system (Figs. 2F and S21–23). Additionally, non-uniform electric field distribution is observed in latticed surfaces when subjected to an external electric field, leading to higher power loss density at the lattice (Fig. S24), suggesting that electromagnetic waves are not only subjected to reflection loss but also diffuse reflection on surfaces with structures. Simulations of the EF direction in the y-z plane (Figs. 2G and S25) demonstrates that the direction of the electric field of the lattice structure changes at the raised lattice. This indicates that the formation of the raised structure on the surface facilitates the enhancement of diffuse EM wave scattering, while influencing the electric field distribution at the surface. The potency of the raised lattice structure can be explained by the bandwidth of GHz frequency electromagnetic waves and its interaction with micrometer scale regular structures through Rayleigh scattering32–35. Previous works indicated that wrinkled structures can effectively enhance electromagnetic wave absorption, with a 5 μm thick wrinkled MXene film for a shielding effectiveness of 58 dB36. Here, we achieved an ultrathin MXene film (2.8 μm) with a patterned lattice structure, exhibiting the nearly similar ultrahigh EMI SE. The unique shielding enhancement mechanism of our lattice architecture lies in its ability to provide additional conductive pathways through the crossed lattices, thereby enhancing the overall electrical conductivity of the film. Simultaneously, the uniform micro/nano lattice configuration induces Rayleigh scattering, which further augments electromagnetic wave absorption. The synergistic enhancement of both reflection and absorption results in a significantly higher total shielding effectiveness in the lattice-patterned MXene compared to other surface-patterned films reported in the field13,36,37 (Fig. 2H).

Mechanical properties and durability under extreme environments
Stable mechanical properties of the MXene/PI film are essential for practical application of high-performance EMI shielding materials. The tensile strength of the MXene/PI composite film is 141 ± 10 MPa, which is 47 times higher than that of the MXene-VAF film (3 MPa). The measured tensile strain of 13 ± 1% is 4.6 times higher than that of the MXene-VAF film (2.8%) (Figs. S26, S27 and Table S8). Fig. S28 illustrates the high strength and flexibility of ultra-thin MXene/PI films. Compared with the reported flexible EMI shielding films, the MXene/PI films offer noticeable advantages in terms of mechanics, flexibility, thickness and EMI SE (Fig. 3A and Table S9)38–46.

In aerospace or defense applications, materials face extreme conditions such as physical shocks, high temperatures, and low temperatures47,48. We performed unidirectional stretching of the lattice-structured MXene/PI film and found that the MXene coating remained uncracked on the PI surface at 8% stretching rate (Fig. 3C). When the stretching rate is 11%, cracks appear in the MXene coating at the lattice connection points (Figs. 3C and S29). During the stretching process, the PI is deformed by the tensile force, and the MXene coating with a raised lattice structure pulls outward with the deformation of the PI. Wavelength becomes larger, and the lattice structure increases energy dissipation and provides a stress cushion (Fig. S30)19. Compared to flat MXene coatings, the lattice-structured MXene coatings are less susceptible to cracking under small stresses. As the tensile force increases, MXene cracks at the raised lattice and the stress is released. The cracks are created on the lattice and do not extend to the entire MXene layer, so they have little effect on the EMI shielding performance. Therefore, when the MXene/PI film is stretched to 11%, the conductivity and EMI SE remains stable (Fig. 3B and Table S10).

Compared to MXene-VAF and flat MXene films, the electrical resistance of the MXene/PI films with lattice structure is virtually unchanged after thousands of bends (Fig. 3D). In sharp contrast, the MXene/PI films obtained after heat treatment have a tight bonding with an adhesion class of 5B due to the strong interaction force between MXene and PAA, which reiterates the role of strong bonding and lattice structure (Figs. 31 and S32). Supplementary Movie 1 clearly shows that for the MXene/PET film, the solution begins to turn cloudy after 1 s of sonication, accompanied by the diffusion of MXene into the aqueous solution. For the MXene-VAF film, cracking is observed after approximately 35 s of sonication, followed by gradual clouding of the solution. In contrast, no detachment of MXene is observed for the MXene/PI film even after 6 h of sonication, and the aqueous solution remains clear (Fig. S33). Compared with flat films, the MXene/PI with lattice structure has higher resistance to physical impact.

Remarkably, the MXene/PI films in ultrasonic treatment, high temperature (300 °C), low temperature (−196 °C) acid solution (pH = 1) for 24 h, and 30 times repeated cyclic thermal shock between the above temperatures (ΔT = 496 °C), maintain an EMI shielding efficiency of more than 75 dB in the X-band. (Fig. 3E, F and Table S11). The stability of the EMI shielding performance of the MXene/PI films treated in harsh environments is attributed to the excellent stability of MXene and PI at both high and low temperatures (Figs. S34 and S35)49. Supplementary Movie 2 demonstrates that MXene/PI films remain capable of withstanding repeated bending and folding without fracture even after removal from liquid nitrogen immersion, highlighting the application potential of latticed MXene in cryogenic environments. At the same time, the mechanical properties of the MXene/PI films remain excellent after treatment in harsh conditions (Fig. S36). In view of the easy oxidization of MXene in humid air, the long-term stability of EMI shielding performance of lattice-structured was investigated and compared with that of MXene-VAF and flat MXene films. As shown in Fig. 3G and Table S12, the EMI SE of the latticed MXene did not decrease significantly in a hygrothermal environment (40 °C, 60–80% humidity) over timescales of months. These results demonstrate that the MXene/PI film is a comprehensive EMI shielding material, which is highly appealing for a wider range of practical applications involving moving components and mechanical deformations.

Joule heating and deicing properties
The MXene/PI films exhibit controllable Joule heating performance, adhering to Joule’s law (Q = U2R−1t) (Fig. S37)50. In contrast, the MXene-VAF fractures at 4 V owing to overheating, while the temperature of the MXene/PET film shows no significant change with increasing voltage, owing to the delamination between MXene and PET during heating (Fig. S38). Benefiting from the high-temperature-resistant polymer substrate and the strong interfacial interaction between MXene and PI, the MXene/PI film exhibits controllable Joule heating performance under applied voltages ranging from 1 to 7 V. The temperature measured by infrared imaging varies from 34.7 to 397.0 °C, showing good agreement with thermocouple readings (Figs. 4A and S39). The surface temperature of the MXene/PI film experiences rapid elevation within 10 s and holds steady under the external voltage (Fig. 4B). The MXene/PI films maintain long-lasting stability after multiple heating and cooling cycles (Fig. S40). Compared with the performance of EMI shielding materials with joule heating in the literature, the MXene/PI films achieve controlled temperature rise at a lower voltage (Fig. 4C and Table S13). The temperature of the MXene/PI films is close to 400 °C at 7 V driving voltage, surpassing the values previously reported for EMI shielding materials with Joule heating performance44,51–72. The convex surface structure may confer the material excellent hydrophobic properties73,74. Compared with the MXene-VAF (34.9°) and flat MXene (50.6°), the lattice-structured MXene exhibits a larger water contact angle of 125° (Fig. 4D). The enhancement of hydrophobicity in the latticed MXene is attributed to the combined effect of its unique lattice-patterned structure and the removal of surface polar groups through heat treatment. When the material is exposed to extremely cold and humid environments, the icing time of the lattice-structured MXene is significantly prolonged compared to the material with flat surface (Fig. 4E, F), which proves that the surface of latticed MXene is less susceptible to freezing in a cold environment. The delayed icing is attributed to the wrinkled morphology of the lattice structure, which facilitates the formation of a stable air cushion beneath the water droplet. This air layer reduces solid-liquid contact and effectively impedes thermal transfer. Once formed on the film, ice can be melted by rapid Joule heating. Obviously, the ice block placed on the films with a low voltage of 3 V on a 20° slope can melt and slide away in 40 s (Fig. 4G). This demonstrates that latticed MXene exhibit low ice adhesion and efficient de-icing capabilities under low voltage and slight inclination, indicating their energy-saving potential and practical applicability in anti-icing and de-icing systems. The EMI SE of the latticed MXene shows no significant change after several Joule heating deicing cycles (Fig. S41), which can be attributed to the excellent electrothermal stability and structural integrity of the lattice-structured MXene under high electrical load (Fig. S42). This indicates that the internal structure of the material remains unchanged after multiple electro-cycling as a smart heater, resulting to stable EMI shielding performance. These results reiterate that the latticed MXene can be applied in cold and humid extreme environments with excellent durability.

We have reported a self-wrinkling-induced lattice-structured MXene obtained by polymer shrinkage in a dehydration reaction. The lattice structure provides scattering interfaces and more electrical conduction paths, thus enhancing the electromagnetic wave loss. The lattice-structure endows the wrinkled MXene with a high EMI SE of up to 81.5 dB for a thickness of 17 μm. Thankstothe unique lattice structure, the MXene retains EMI shielding effectiveness above 75 dB even after enduring mechanical stretching, ultrasonic treatment, high/low temperatures, acidic solutions, and hygrothermal environment. Furthermore, the MXene/PI films exhibit also hydrophobicity and fast Joule-heat de-icing properties. This work introduces a promising approach for spontaneous patterning of inorganic materials with demonstrated potential for EMI shielding applications in a variety of harsh environments or demanding operating conditions.

Methods
Synthesis of Ti3C2Tx MXene Flakes. Few-layer Ti3C2Tx flakes were synthesized by selective etching of Ti3AlC2 powder using LiF/HCl solvent. Firstly, 7.5 mL of deionized water was added to 22.5 mL of analytically HCl (37.0 wt%) and diluted to obtain a hydrochloric acid solution with a concentration of 9 M. Then the prepared hydrochloric acid solution was added to a 100 mL of PTFE reactor, followed by the addition of 1.6 g of LiF, and stirred for 30 min. Then 1 g Ti3AlC2 was slowly added to the above solution and stirred continuously at 35 °C for 24 h. The product was washed with deionized water and centrifuged at 1380 × g. Finally, the few-layer Ti3C2Tx MXene dispersion solution was obtained by ultrasonication under the protection of argon gas stream for 1 h, followed by centrifugation at 1380 × g for 20 min. The obtained low-layer MXene solution was centrifuged at 13640 × g for 30 min at high speed to obtain concentrated Ti3C2Tx condensation, and then the MXene condensation was diluted with water into 40 mg/mL MXene solution.

Preparation of Ti3C2Tx MXene/Polyimide (PI) composite film. A certain amount of 4,4′-oxydianicurve (ODA) was added into a clean three-neck round-bottom flask, and organic solvent DMF was added subsequently. After the ODA is completely dissolved, an appropriate amount of Pyromellitic dianhydride was added in batches, and the mixture was mechanically stirred in an ice-water bath for 4 h. The yellow colloid in the three-necked flask is poly(amic acid) (PAA) solution. The latticed MXene was prepared using blade-coating on PAA surface and heat treatment. Firstly, the PAA solution was coated on glass and then dried in a vacuum oven at 60 °C for 40 min. The MXene (40 mg/mL) solution was blade-coated on PAA and dried in a vacuum oven at 60 °C for 1 h. The obtained MXene/PAA film was heat-treated in N2 atmosphere (gradient temperature rise: 80 °C, 30 min; 120 °C, 30 min; 180 °C, 30 min; 250 °C, 30 min; 300 °C, 30 min), and latticed MXene was obtained. The thickness of the PAA layer is regulated by changing the height H = 125, 500, 2000 μm between the PAA and the blade edge. MXene was blade-coated on PAA once, twice, three times, five times, and eight times to regulate the thickness of MXene on PAA, where H(PAA) = 500 μm, H(MXene) = 100 μm. The thicknesses of the latticed MXene after heat treatment were 0.7 μm, 1.5 μm, 2.8 μm, 7 μm, and 17 μm, which were named as 1, 2, 3, 4, and 5, respectively. For comparison, the MXene solution was blade-coated onto PET, PTEF, PVDF, glass to study MXene morphology and adhesion.

Statistics and Reproducibility. The reproducibility of the synthesis process for surface-patterned MXene films was rigorously evaluated through ten independent experimental replicates under identical conditions. The resulting structural morphology and key functional characteristics, including EMI shielding effectiveness, mechanical strength, Joule heating efficiency, hydrophobicity, and deicing performance, were all confirmed to be highly consistent across every replicate.

Material characterization. The morphology was observed by a scanning electron microscope (SEM, Quanta 250 FEG and JEOL, JSM-7500F). The transmission electron microscopy images of MXene flakes were recorded by field-emission transmission electron microscopy (FETEM, JEM-2100F). The crystal structure was investigated by powder X-ray diffraction (XRD, Rigaku Ultima IV). The surface element and element valence states were investigated by X-Ray Photoelectron Spectroscopy (XPS, Thermo Scientific K-Alpha). The chemical bonds of the composite films were analyzed via a Fourier transform infrared spectroscopy (FTIR, Nicolet iS50, Thermo Fisher Scientific, Waltham, MA). The height morphology of MXene flakes was characterized by the atomic force microscope (AFM, dimension icon, Bruker). The thermal stability was investigated by a thermal analyzer (Netzsch, STA449F3). Thermal imaging camera was used to record the temperature of composite films in the photothermal experiment (ST9450). The infrared emissivity of MP and CMP was revealed by a dual-band emissivity meter (IR-2, Shanghai Chengbo Optoelectronic Technology, China) in the wavelength range of 2–25 µm.

The sample surface square resistance/electrical conductivity was measured by KDB-3 double combination four-point probe tester, the electrical conductivity of the composite film is calculated as follows:

σ = 1 / (R × t) (1)

where σ (S/cm) denotes the electrical conductivity and t (cm) denotes the thickness of the sample.

The EMI shielding performance of the composite films was tested using an Agilent PAN-N5244A vector network analyzer via the waveguide method (X band). The measured scattering parameters (S11 and S21) were used to calculate the absorption, reflection, and total shielding value of the samples. EMI SE (SET) was divided into three parts: reflection loss (SER), absorption loss (SEA), and multiple reflection loss (SEMR).

The mechanical property was tested by a Shimadzu AGS-X 1 kN universal mechanical testing machine, the load-displacement and stress-strain data are transformed as follows:

σ = F / (d × t) (2)

ε = x / l × 100% (3)

Where σ (MPa) denotes stress and ε denotes strain, d (mm), t (mm) and l (mm) represent the width, thickness and the length of the sample, respectively.

MXene-VAF, MXene/PET and MXene/PI films were respectively placed on a cold table at −15 °C and relative humidity (RH) < 20% to observe the icing process of the films.

Electrical conductivity and EMI SE calculation of lattice-structured MXene. To understand the contribution of the lattice structure to the excellent EMI shielding of the composite films, the conductivity of the lattice-structured MXene (σlatticed MXene) were calculated as follow (Fig. S18),

σlatticed MXene = (φA + φB R) σA / (φA + φB R + φA) (4)

Where φA and φB is the volume fractions of lattice network and flat bottom, R is the ratio of the thickness of the flat bottom to the total MXene film, σA is electrical conductivity of MXene. Since (φA + φB R) > R(φA + φB R + φA), the conductivity of the latticed MXene film is larger than that of a flat one. According to Simon’s formula, the EMI SE can be expressed as 4,

EMI SE = 50 + 10 lg (σ / f) + 1.7t σf (5)

where f (MHz) is the frequency of incident EMWs, σ (siemens per centimeter) is the electrical conductivity, and t (centimeters) is the thickness of the EMI shielding film.

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "In this manuscript, the authors proposed a homogeneous strain strategy to achieve self-wrinkling-induced lattice-structured\nMXene by uniform polymer shrinkage due to dehydration, which is an interesting and novel research result and has certain\nsignificance in this field. I believe that with some minor modifications, this manuscript satisfies the standards of Nature\nCommunications.\n1. The author blade-coated the concentrated MXene solution onto the PAA surface. Was the PAA in a solid state or gel state\nduring the blade-coating process, and does the PAA still contain solvent?\n2. The article mentions that MXene does not form lattice-like structures on PET, PTFE, PVDF, or glass due to the lack of\ninteraction forces between MXene and these substrates. Does MXene form patterned structures on other polymeric surfaces\nthat can establish bonding interactions with MXene?\n3. Figure 1C shows the cross-sectional view of MXene/PI. Is MXene prone to delamination from the PI surface? There is a\nmodulus mismatch between MXene and the polymer. Why do more pronounced wrinkles and protrusions form between\nMXene and the polymer during shrinkage? Do hydrogen bonds exist between MXene and the polymer after heat treatment?\n4. When testing the EMI shielding performance of the lattice-structured MXene, is the PI substrate included? Does the\npresence of the PI substrate affect the EMI shielding efficiency of the film?\n5. Compared to flat structures, lattice structures exhibit higher EMI shielding efficiency. The article mentions that this\nimprovement is due to the increase in additional conductive pathways and surface scattering effects. Which of these two\nfactors has a more significant impact on the EMI shielding performance?\n6. Is the MXene/PI film prone to oxidation or delamination when exposed to air, potentially affecting its practical application\nin real-world environments?\n7. Figure 3B elucidates the EMI shielding performance of the MXene/PI film after stretching. Does the MXene/PI film exhibit\nelastic recovery (return to its original state) after stretching, and can the cracks be healed or repaired?\n8. The lattice MXene exhibits a hydrophobic contact angle of 125° due to its surface lattice structure, but it does not reach\nsuperhydrophobicity (150°). Has the author attempted further surface energy reduction treatments (e.g., chemical\nmodification or nanostructuring) to achieve superhydrophobicity?", "reviewer_2": "Manuscript Number: NCOMMS-25-19801-T\nRecommendation: Major Revision\nThe manuscript titled “Regular-wrinkling tunable MXene lattice for electromagnetic interference shielding” presents an\ninteresting approach where PAA film/MXene composites are thermally treated on PI films to fabricate wrinkle-tunable MXene\ncomposite film. The structural transformation improved mechanical strength, EMI shielding and Joule heating performance.\nWhile the concept is very interesting, the current version of the manuscript lacks clarity in several key areas, making it\ndifficult to fully assess the validity and significance of the findings. Therefore, I would like to recommend a major revision\nbefore reconsideration for publication in Nature Communications.\nMy specific comments are as follows:\n1. Precise sample characterization is essential in this study, particularly in maintaining consistent dimensions and electrical\nconductivity. However, detailed information is missing. Authors should provide comprehensive data for all samples,\nincluding effective thickness (thickness of flat area and thinness of peak area), and corresponding electrical conductivity\nvalues.\n2. The authors state, \"During the high-temperature treatment process, the dehydration cyclization of the PAA leads to\nuniform contraction of the PI (Fig. S6).\" However, Figure S6 depicts only the synthesis process of poly(amic acid) precursors\n(PAA) and polyimide (PI). The authors should provide supporting evidence for the claim regarding uniform contraction of PI.\n3. The authors should report the d-spacing values following the removal of interlayer water from the composite for a more\ncomplete analysis.\n4. The amplitude presented in Figure S8 does not align with the 2-micron claim. The authors are advised to review this\ninconsistency.\n5. The authors should further clarify this expression: “For an effective comparison of EMI shielding coefficients, the thickness\nof the flat MXene film should also be provided. Compared with the flat MXene, the reflection loss (SEA) and absorption loss\n118 (SER) of the latticed MXene increase by 10.1 dB and 1.7 dB (Table S4), while the absorption coefficient (A) increase by\n1% (Fig. S15).”\n6. The authors should further clarify how a 1% increase in the absorption coefficient leads to a 31% improvement in EMI\nshielding performance of the MXene lattice. Moreover, the authors have demonstrated that the lattice structure contributes\nadditional conductive pathways and an increased reflective surface compared to flat MXene, which should be discussed in\nmore detail.\n7. The authors should provide experimental electrical conductivity data for latticed, vacuum-filtered, and flat MXene films. In\naddition, conductivity and EMI SE values calculated using equation 4 and 5 should be included for better comparison and\nunderstanding.\n8. Author should provide the detail discussion on the multiple reflection effect in this study.\n9. The original and retained values of EMI shielding effectiveness (SE) should be included in the text to demonstrate the\nlong-term stability of the latticed MXene structure for better understanding.\n10. The term \"MXene/PI films\" should be clarified: does it refer to latticed MXene or the entire MXene composite? Similarly,\nthe title of Figure 4 should reflect this clarification.\n11. In the synthesis section, the authors mention using the HCl/LiF method for fabricating MXene. However, it is unclear why\nsonication is necessary, as this process is commonly used for synthesizing single-layer MXene.\n12. References 19 and 33 appear to be identical and should be revised accordingly.\n13. The authors are encouraged to provide detailed discussions for all figures and subfigures in the supporting information\nsection to enhance the overall clarity and completeness of the manuscript."}, "author_response": "Response to Reviewers’ Comments\nThank you very much for considering our work in the manuscript entitled \" Regular-\nwrinkling tunable MXene lattice for electromagnetic interference shielding \"(Full\nPaper, Manuscript ID NCOMMS-25-19801-T) authored by Shan Zhang, Juntao Wu,\nZhi-Ling Hou, Pengfei Hu, Bo Cai, Chenming Liang, Lu Zhou, Wenhao Liang, Yufeng\nXue, Martin C. Koo, Pei-Yan Zhao, Li-Min Liu, Mingjie Liu and Guang-Sheng Wang.\nIn addition, we truly appreciate the editor and reviewers for their careful reading of our\nmanuscript and valuable suggestions. The insightful comments have provided us a\nchance to further improve the quality of our manuscript. The manuscript has been\nrevised in detail according to the comments provided by the reviewers. The changes to\nthe text are highlighted in YELLOW.\nThe following is our response to the comments of the reviewers\nReviewer 1：\nComments: In this manuscript, the authors proposed a homogeneous strain strategy to\nachieve self-wrinkling-induced lattice-structured MXene by uniform polymer\nshrinkage due to dehydration, which is an interesting and novel research result and has\ncertain significance in this field. I believe that with some minor modifications, this\nmanuscript satisfies the standards of Nature Communications.\nReply: Thank you for your positive and constructive comments, which are of great\nsignificance for improving the quality and rigor of our manuscript.\nQ1: The author blade-coated the concentrated MXene solution onto the PAA surface.\nWas the PAA in a solid state or gel state during the blade-coating process, and does the\nPAA still contain solvent?\nReply: The PAA was first dried in an oven at 60°C for 40 minutes to remove the\nmajority of the solvent. At this stage, the PAA exists in a solid state but still retained\n25-30% residual solvent. This persistence is attributed to the formation of stable\ncomplexes between PAA and DMF1.\nQ2: The article mentions that MXene does not form lattice-like structures on PET,\nPTFE, PVDF, or glass due to the lack of interaction forces between MXene and these\nsubstrates. Does MXene form patterned structures on other polymeric surfaces that can\nestablish bonding interactions with MXene?\nReply: Thanks you for the insightful question. When deposited on a polymer substrate,\nMXene exhibits a tendency for relative slippage against the substrate under externally\napplied stress. If bonding interactions exist between MXene and the substrate, the\naccumulated stress cannot be released through slippage. Instead, it is relieved through\nbuckling deformation. Consequently, MXene forms surface patterns via buckling on\npolymer surfaces capable of establishing such bonding interactions. This phenomenon\nextends beyond polyimide substrates.\nQ3: Figure 1C shows the cross-sectional view of MXene/PI. Is MXene prone to\ndelamination from the PI surface? There is a modulus mismatch between MXene and\nthe polymer. Why do more pronounced wrinkles and protrusions form between MXene\nand the polymer during shrinkage? Do hydrogen bonds exist between MXene and the\npolymer after heat treatment?\nReply: MXene exhibits strong resistance to peeling from the PI surface, as empirically\nconfirmed by the peeling stability test results in Section 3 (Supplementary Fig. 30 and\n31) of this work. During the thermal treatment process, PAA undergoes dehydration-\ninduced cyclization to form PI, with stress released through volumetric shrinkage.\nHowever, the accumulated stress in MXene cannot be relieved due to its robust bonding\nwith the polymer matrix, consequently manifesting as buckling deformation. Hydrogen\nbonding between the polymer and MXene is established prior to thermal treatment.\nDuring heating, partial dissociation occurs between the original hydrogen bonds\nconnecting PAA and MXene. Following the conversion of PAA to PI via dehydration\ncyclization, new van der Waals interactions and hydrogen bonds form between the -OH\ngroups on MXene nanosheets and C=O moieties in PI molecular chains.\nQ4: When testing the EMI shielding performance of the lattice-structured MXene, is\nthe PI substrate included? Does the presence of the PI substrate affect the EMI shielding\nefficiency of the film?\nReply: Thank you for the thought-provoking questions. The electromagnetic\ninterference (EMI) shielding performance of latticed MXene reported in this work\nincludes contributions from the PI substrate. We first measured bare PI and PET films\nwithout MXene loading, and their EMI shielding performance is as follows:\nFig. R1 EMI SE of the PET and PI film.\nResults demonstrate that both PI and PET films function as electromagnetically\ntransparent materials, exhibiting negligible EMI shielding performance. This\nobservation aligns with other reported works. Thus, it can be concluded that the\npresence of PI substrates does not compromise the EMI shielding effectiveness of the\ncomposite films.\nQ5: Compared to flat structures, lattice structures exhibit higher EMI shielding\nefficiency. The article mentions that this improvement is due to the increase in\nadditional conductive pathways and surface scattering effects. Which of these two\nfactors has a more significant impact on the EMI shielding performance?\nReply: Thanks you for this intriguing query. According to the test results in Figure 2A,\nthe latticed MXene exhibits enhanced shielding effectiveness by absorption (SE ) and\nA\nshielding effectiveness by reflection (SE ) compared to flat MXene. This indicates that\nR\nboth additional conductive pathways and surface scattering effects contribute to the\nEMI shielding performance of the latticed MXene. According to Figure S17, the 1%\nincrease in the reflection coefficient (R) indicates that the additional conductive paths\nintroduced by the lattice structure enhance electrical conductivity. This constitutes the\nprimary contributor to the 31% improvement in EMI SE.\nQ6: Is the MXene/PI film prone to oxidation or delamination when exposed to air,\npotentially affecting its practical application in real-world environments?\nReply: Indeed, oxidation/delamination is a valid concern towards the practicality of the\nMXene/PI film. Therefore, we conducted experimental tests on the durability of latticed\nMXene, as in detailed the third and fourth sections of the article. Due to its unique\nsurface structure, MXene with a lattice structure has a hydrophobic angle of 125°,\nwhich can effectively prevent contact with water compared to EMI shielding materials\nwithout hydrophobic properties, thereby slowing down the oxidation rate. The special\nlattice structure further enhances the interaction force between MXene and PI, and it\ndoes not fall off even after 6 hours of ultrasonic treatment. In conclusion, it is proven\nthat the MXene/PI film is not prone to oxidation or delamination, has good usability,\nand even has great application prospects in extreme environments.\nQ7: Figure 3B elucidates the EMI shielding performance of the MXene/PI film after\nstretching. Does the MXene/PI film exhibit elastic recovery (return to its original state)\nafter stretching, and can the cracks be healed or repaired?\nReply: Thank you for the interesting question. Since neither PI nor MXene is an\nelastomer, MXene and PI will retract after stretching and releasing the tension, but they\nwill not return to their original state. The lattice structure can enable MXene/PI films\nto exhibit stress buffering under small stress/strain, but once cracks occur under large\nstress, they cannot be repaired. Therefore, the MXene/PI films prepared in this work\nare suitable for applications in scenarios subject to small stress impacts. In the following\nwork, MXene can be loaded onto an elastomer and self-healing small molecules can be\nintroduced to prepare EMI shielding materials suitable for scenarios subject to large\nstress impacts.\nQ8: The lattice MXene exhibits a hydrophobic contact angle of 125° due to its surface\nlattice structure, but it does not reach superhydrophobicity (150°). Has the author\nattempted further surface energy reduction treatments (e.g., chemical modification or\nnanostructuring) to achieve superhydrophobicity?\nReply: We attempted to deposit perfluorosilane on the surface of the latticed MXene\nusing the vapor deposition method, resulting in a film with a hydrophobic angle of 139°.\nHowever, the EMI shielding performance of the film was somewhat reduced (Figure\nR2). Therefore, in the subsequent work, we considered introducing nano-scale\nprotrusions on the lattice structure to further increase the hydrophobic angle of the film\nand simultaneously enhance the EMI shielding performance of the material.\nFig. R2 (A) Water contact angle (B) EMI SE of latticed MXene and latticed MXene-\nPFDTES.\n[1] Brekner, M.-J. et al. J. Polym. Sci., Part A: Polym. Chem. 25: 2005-2020 (1987).\nReviewer 2:\nComments: The manuscript titled “Regular-wrinkling tunable MXene lattice for\nelectromagnetic interference shielding” presents an interesting approach where PAA\nfilm/MXene composites are thermally treated on PI films to fabricate wrinkle-tunable\nMXene composite film. The structural transformation improved mechanical strength,\nEMI shielding and Joule heating performance. While the concept is very interesting,\nthe current version of the manuscript lacks clarity in several key areas, making it\ndifficult to fully assess the validity and significance of the findings. Therefore, I would\nlike to recommend a major revision before reconsideration for publication in Nature\nCommunications.\nReply: We are very grateful for the recommendation and positive comments made by\nthe reviewer. The concerns of the reviewer are thoroughly addressed in a point-by-point\nmanner as follows, upon which the manuscript is revised accordingly.\nQ1: Precise sample characterization is essential in this study, particularly in\nmaintaining consistent dimensions and electrical conductivity. However, detailed\ninformation is missing. Authors should provide comprehensive data for all samples,\nincluding effective thickness (thickness of flat area and thinness of peak area), and\ncorresponding electrical conductivity values.\nReply: Thank you for your constructive suggestion. The thickness of the samples\n(thickness of the flat area and the peak area) was measured by scanning electron\nmicroscopy (SEM). The cross-sectional SEM images and specific data are presented\nbelow. The lattice structure is spontaneously formed, and the flat area and the peak area\nare the same MXene. It can also be seen from the SEM images that the interlayer\nspacing of MXene in the flat area and the peak area are practically identical. Combined\nwith the four-probe conductivity meter test, the conductivity values of different points\nof the lattice MXene film are highly similar, thus it is concluded that the conductivity\nvalues of the flat area and the peak area are the same. The conductivity values of\ndifferent samples are also shown in the table below.\nThe cross-sectional SEM images of the flat MXene and the latticed MXene mentioned\nin Figure 2A of the manuscript are as follows:\nFig. R3 (Fig. 16 in supplementary information) cross-sectional SEM images of(A) flat\nMXene, (B) latticed MXene on PI surface.\nTable R1 (Supplementary Table 4 in the revised supplementary information) The\nthickness and electrical conductivity of flat MXene and latticed MXene.\nThinness of peak Electrical\nThickness of flat area\nSample area conductivity\n(μm)\n(μm) (S/cm)\nFlat MXene 4.0 0 2500\nLatticed MXene 2.8 1.8 3500\nIn response to this comment, Figure R3 and Table R1 have been added to Figure S16\nand Table S4 in the supporting information.\nThe cross-sectional SEM images of MXene-VAF, flat MXene and latticed MXene\nmentioned in Figure 2D of the manuscript are as follows:\nFig. R4 (Fig. 18 in supplementary information) SEM images of the cross-section for\ndifferent (A) MXene-VAF, (B) flat MXene and (C) latticed MXene films.\nTable R2 (Supplementary Table 6 in the revised supplementary information) The\nthickness and electrical conductivity of MXene-VAF, flat MXene and latticed MXene.\nThinness of peak Electrical\nThickness of flat\nSample area conductivity\narea (μm)\n(μm) (S/cm)\nMXene-VAF 13.0 0 2900\nflat MXene 8.0 0 3500\nLatticed MXene 2.8 1.8 3500\nIn response to this comment, Figure R4 and Table R2 have been added to Figure S18\nand Table S6 in the supporting information.\nThe cross-sectional SEM images of latticed MXene films of different thicknesses\nmentioned in Figure 2E of the manuscript are as follows:\nFig. R5 (Fig. 19 in supplementary information) SEM images of the cross-section for\ndifferent thicknesses of latticed MXene on PI surface.\nTable R3 (Supplementary Table 7 in the revised supplementary information) The\nthickness and electrical conductivity of the latticed MXene with various thicknesses.\nThinness of peak Electrical\nThickness of flat\nSample area conductivity\narea (μm)\n(μm) (S/cm)\n1 0.7 0.5 600\n2 1.5 1.0 1000\n3 2.8 1.8 3500\n4 7.0 3.0 5900\n5 17.0 10.0 8000\nIn response to this comment, Figure R5 and Table R3 have been added to Figure S19\nand Table S7 in the supporting information.\nQ2: The authors state, \"During the high-temperature treatment process, the dehydration\ncyclization of the PAA leads to uniform contraction of the PI (Fig. S6).\" However,\nFigure S6 depicts only the synthesis process of poly(amic acid) precursors (PAA) and\npolyimide (PI). The authors should provide supporting evidence for the claim regarding\nuniform contraction of PI.\nReply: Thanks you for pointing out this deficiency in the manuscript. We removed\nPAA/MXene film from the glass substrate and then subjected it to heat treatment. The\nmacroscopic images and cross-sectional SEM images of the PAA before thermal\ntreatment and the PI after thermal imidization are shown below. It can be seen from the\nfigures that the area of PAA before thermal treatment was 66 cm and the thickness\nwas 35 μm; after thermal treatment, the area was 5.45.4 cm and the thickness was 30\nμm. This proves that the process of PAA ring formation and dehydration results in\nuniform volume contraction.\nFig. R6 (Fig. 7 in supplementary information) (A) PAA film on grid paper (66 cm).\n(B) SEM images of the cross-section for PAA film. (C) PI film on grid paper (5.45.4\ncm). (D) SEM images of the cross-section for PI film.\nIn response to this comment, Figure R6 have been added to Figure S7 in the supporting\ninformation.\nQ3: The authors should report the d-spacing values following the removal of interlayer\nwater from the composite for a more complete analysis.\nReply: Thanks you for the excellent suggestion. The heat treatment process at 300°C\ncan effectively remove the interlayer water molecules of MXene. According to Figure\nR7A, the (002) peak position of MXene on the PAA surface is 2θ =7.2°. Using\npeak\nBragg law and Cu Kα radiation (λ=1.5418A), the d-spacing is calculated as follows:\nθ = 2θ peak= 7.2° = 3.6°\n2 2\nsin(3.6°)≈0.0628\n𝜆 1.5418 1.5418\nd= = = ≈1.23 nm\n2𝑠𝑖𝑛𝜃 2×0.0628 0.1256\nThe d-spacing of MXene on the PAA surface is approximately 1.23 nm.\nThe (002) peak position of MXene on the PI surface is 2θ =8.2°. According to Bragg\npeak\nlaw and Cu Kα radiation (λ=1.5418 A), the d-spacing is calculated as follows:\nθ = 2θ peak= 8.2° = 4.1°\n2 2\nsin(4.1°)≈0.0715\n𝜆 1.5418 1.5418\nd= = = ≈1.08 nm\n2𝑠𝑖𝑛𝜃 2×0.0715 0.1430\nThe d-spacing of MXene on the PI surface is approximately 1.08 nm.\nFig. R7 (Fig. 8 in supplementary information) (A) The XRD patterns and (B)\ncomparison of d-spacing values of MXene, MXene/PAA and MXene/PI films.\nIn response to this comment, Figure R7 have been added to Figure S8 in the supporting\ninformation. The revised version includes the changes in the MXene layer spacing\nbefore and after heat treatment.\nPage 5, Paragraph 1, Line 5 in the revised manuscript:\nAs a result, the MXene coating shrinks further inward on the PI surface, with the\nMXene layer spacing decreasing from 1.23 to 1.08 nm (Fig. S8), and the amplitude of\nthe lattices increases to 1~2 μm (Fig. S9)\nQ4: The amplitude presented in Figure S8 does not align with the 2-micron claim. The\nauthors are advised to review this inconsistency.\nReply: Thank you for pointing out the lack of clarity regarding the 2-micron claim. The\nAFM images of MXene on PI are presented in Figure R8A (in the manuscript, 1E), and\nthe height statistics are shown in Figure R8B. From the Figure R8B, the amplitude of\nMXene on PI is 1-2 μm. The cross-sectional SEM image in the supplementary\ninformation S9 was tilted, which may have errors. The cross-sectional SEM of MXene\non PI are re-tested and the results are shown in Figures R8C and D. The statement in\nthe article that the amplitude of MXene on PI is 2 μm is also not very rigorous.\nTherefore, we changed the corresponding position in the main text to an amplitude of\n1-2 μm.\nFig. R8 (Fig. 9 in Supplementary information) (A) AFM 3D images with (B) height\nprofiles of the latticed MXene on PI surface. (C, D) SEM images of the cross-section\nfor latticed MXene on PI surface.\nIn response to this comment, Figures R8B, C and D have been added to Figure S9 in\nthe supporting information. The revised version includes the variation in the amplitude\nheight of latticed MXene.\nPage 5, Paragraph 2, Line 7 in the revised manuscript:\nAs a result, the MXene coating shrinks further inward on the PI surface, with the\nMXene layer spacing decreasing from 1.23 to 1.08 nm (Fig. S8), and the amplitude of\nthe lattices increases to 1-2 μm (Fig. S9)\nQ5: The authors should further clarify this expression: “For an effective comparison of\nEMI shielding coefficients, the thickness of the flat MXene film should also be provided.\nCompared with the flat MXene, the reflection loss (SEA) and absorption loss (SER) of\nthe latticed MXene increase by 10.1 dB and 1.7 dB (Table S4), while the absorption\ncoefficient (A) increase by 1% (Fig. S15).”\nReply: Thanks you for the constructive suggestion. The thickness of the flat MXene\nfilm is shown in Figure R3 (Fig. S16) and Table R1 (Table S4). Re-examination of the\nreflectance (R) and absorptance (A) values for flat and lattice MXene films identified\nan error in previous computations. The corrected results show that the 98% R and 2%\nA for lattice MXene. Compared with the flat MXene (with R is 97% and A is 3%), the\nR value of lattice MXene increased by 1%. Updated bar plots comparing the R and A\nof flat and lattice MXene are now provided in Supplementary Figure S17. Compared\nwith the flat MXene, the reflection loss (SE ) and absorption loss (SE ) of the latticed\nA R\nMXene increase by 10.3 dB and 1.7 dB (Table S5). This demonstrates that the enhanced\nEMI SE of the latticed MXene stems from both the improved SE due to enhanced\nR\nelectrical conductivity and the increased SE resulting from the surface structure\nA\npromoting diffuse reflection of electromagnetic waves. The core conclusion-that\nenhanced EMI shielding in lattice MXene stems from concurrent improvements in both\nreflection and absorption-remains valid. Critically, the 1% increase in reflectance (R)\nindicates that the primary cause of enhanced electromagnetic interference lies in the\nimproved electrical conductivity resulting from additional conductive paths introduced\nby the lattice structure, which subsequently enhances the reflection of electromagnetic\nwaves.\nIn response to this comment, the revised version includes a comparison and analysis of\nthe conductance data of flat and latticed MXene, as well as the reasons and dominant\nfactors for the increase in the EMI SE value of latticed MXene.\nPage 5, Paragraph 4, Line 32-35, in the revised manuscript:\nElectrical conductivity is a critical parameter for evaluating the EMI shielding\nperformance of MXene. Firstly, the conductivity of flat MXene on PET and lattice\nMXene on PI under the same preparation conditions is measured. The latticed MXene\nexhibited a higher conductivity of 3500 S/cm compared to 2500 S/cm for the flat\nMXene (Fig. S16 and Table S4).\nPage 6, Paragraph 1, Line 4-7, in the revised manuscript:\nThis demonstrates that the enhanced EMI SE of the latticed MXene stems from both\nthe improved SE due to enhanced electrical conductivity and the increased SE\nR A\nresulting from the surface structures responsible for promoting diffuse reflection of\nelectromagnetic waves.\nMeanwhile, we have included the conductivity data (Fig. S16 and Table S4) and\nupdated bar plots of A and R coefficients and data (Fig. S17 and Table S5) in the\nsupplementary information.\nQ6: The authors should further clarify how a 1% increase in the absorption coefficient\nleads to a 31% improvement in EMI shielding performance of the MXene lattice.\nMoreover, the authors have demonstrated that the lattice structure contributes additional\nconductive pathways and an increased reflective surface compared to flat MXene,\nwhich should be discussed in more detail.\nReply: Thank you for the thought-provoking question. Based on re-examined\ncalculations, the 1% increase in R is identified as the dominant factor driving the 31%\nenhancement in EMI SE for lattice-structured MXene. Although 1% may seem small,\nin the context of high shielding effectiveness, its absolute value contribution is\nsignificant. The lattice architecture enhances EMI shielding through dual mechanisms:\n(i) Amplified wave absorption due to Rayleigh scattering of GHz electromagnetic\nwaves at micron-scale surface structures; (ii) Enhanced wave reflection originating\nfrom additional conductive pathways and multi-reflection events at the patterned\ninterfaces.\nThe core advantages of the lattice structure: It is not merely a simple \"increase in area\",\nbut through the carefully designed micro-nano structures, it simultaneously introduces\nenhanced conductive networks and efficient sub-wavelength scattering mechanisms\n(Rayleigh scattering).\nIn response to this comment, the revised version includes: (i) the reasons for the\nenhancements in SE and SE , (ii) how the 1% increase in reflection coefficient\nA R\nresulted in a 31% improvement in the EMI shielding effectiveness of the MXene lattice,\nand (iii) the impacts of increased conductive pathways and enlarged reflection surfaces\non EMI shielding performance.\nPage 6, Paragraph 1, Line 7-10, in the revised manuscript:\nAccording to Figure S17, the 1% increase in the reflection coefficient (R) indicates that\nthe additional conductive paths introduced by the lattice structure enhance electrical\nconductivity. This constitutes the primary contributor to the 31% improvement in EMI\nSE.\nQ7: The authors should provide experimental electrical conductivity data for latticed,\nvacuum-filtered, and flat MXene films. In addition, conductivity and EMI SE values\ncalculated using equation 4 and 5 should be included for better comparison and\nunderstanding.\nReply: Thanks you for the insightful suggestion. The experimental electrical\nconductivity data of the lattice, vacuum filtration and flat MXene films are presented\nin Table R2(Table S6 in supporting information).\nThe electrical conductivity of MXene-VAF was measured at 2900 S/cm using a four-\n𝜎\nprobe conductivity meter, according to Equation EMI SE=50+10lg( )+1.7t√𝜎𝑓(5)\n𝑓\n𝑓\nThe EMI SE of MXene-VAF averages 56.6 dB in the X-band, calculated from 201\nequally spaced frequency points across the 8.2-12.4 GHz range.\nThe electrical conductivity of flat MXene was measured at 3500 S/cm using a four-\n𝜎\nprobe conductivity meter, according to Equation EMI SE=50+10lg( )+1.7t√𝜎𝑓(5)\n𝑓\n𝑓\nThe EMI SE of flat MXene averages 53.5 dB in the X-band, calculated from 201\nequally spaced frequency points across the 8.2-12.4 GHz range.\nFig. R9 (Fig. 21 in Supplementary information) (A) SEM images of the cross-section\nfor latticed MXene on PI surface. (B) The cross-sectional equivalent diagram of the\nlatticed MXene. (C, D) SEM image with different magnifications of the latticed\nMXene.\nThe electrical conductivity of flat-structured MXene with a thickness of 2.8 μm after\nheat treatment was measured as 𝜎 =3000 S/cm. According to the cross-sectional SEM\n𝐴\nimage of the MXene lattice shown in Figure R9A, the cross-sectional equivalent\ndiagram of the MXene lattice is presented in R9D.\nThe cross-sectional area S of a single fold is:\nA1\nS\nA1\n=∫ 1.25 (−1.153𝑥2 +1.8)dx=3.0 μm2\n1.25\nThen the volume V of a single fold is:\nA1\nV =S 58 μm=174 μm3\nA1 A1\nAccording to Figure R9C, D, five wrinkles along the x-direction and five along the y-\ndirection are observed within a 58×58 μm region. Therefore, within the range of 58×58\nμm, the volume 𝜑 of the lattice is:\n𝐴\n𝑉 =174 μm3×10=1740 μm3\n𝐴\n𝑉 =(58×58×2.8) μm3=9419 μm3\n𝐵\n1740 9419\n𝜑 = =0.156, 𝜑 = =0.844\n𝐴 𝐴\n1740+9419 1740+9419\n2.8\nR= = 0.6\n1.8+2.8\nAccording to Formula 𝜎 =\n(𝜑𝐴+𝜑𝐵𝑅)\n𝜎 (4)\n𝑙𝑎𝑡𝑡𝑖𝑐𝑒𝑑 𝑀𝑋𝑒𝑛𝑒 𝐴\n𝑅[𝜑𝐴 (𝜑𝐴+𝜑𝐵𝑅)+𝜑𝐵]\n(0.156+0.8440.6)\n𝜎 = 3000\n𝑙𝑎𝑡𝑡𝑖𝑐𝑒𝑑 𝑀𝑋𝑒𝑛𝑒 0.6[0.156(0.156+0.8440.6)+0.844]\nThe calculated σ value of 3498.6 S/cm closely matches the experimentally measured\nconductivity of 3500 S/cm for latticed MXene, thereby validating the feasibility of\nEquation (4).\n𝜎\naccording to Equation EMI SE=50+10lg( )+1.7t√𝜎𝑓(5)\n𝑓\nThe EMI SE of latticed MXene averages 48.2 dB in the X-band, calculated from 201\nequally spaced frequency points across the 8.2-12.4 GHz range.\nBased on the above calculation results, the theoretical and measured data of MXene-\nVAF, flat MXene and latticed MXene films are presented in Figure R10.\nFig. R10 (Fig. S22 in Supplementary information) Experimental EMI SE and\ntheoretical EMI SE calculated based on Simon formula of MXene-VAF, flat MXene\nand latticed MXene films.\nThe calculation results show that the electrical conductivity of the lattice structure has\nincreased from 3000 S/cm to 3498.6 S/cm. The EMI SE calculated by the Simon\nformula has been improved from 47.3 to 48.2 dB, verifying that the lattice structure can\nenhance the electromagnetic shielding efficiency of the material. The calculated values\nof MXene-VAF and Flat MXene are higher than the experimental values, but the\ncalculated value of latticed MXene is lower than the experimental value. The reason is\nthat the Simon formula only considers the relationship between conductivity and\nshielding efficiency, while surface diffuse reflection caused by the surface structure are\nnot taken into account. In summary, the calculation results are consistent with the test\nresults in Figure 2A and S17: the increase in conductivity and the increase in surface\ndiffuse reflection jointly lead to a higher EMI SE for latticed MXene at the same\nthickness.\nIn response to this comment, Figures R9 and R10 have been added to Figure S21 and\nS22 in the supporting information. The revised version includes the calculated\nconductivity using Equations 4 and 5, along with the measured conductivity, and the\nanalysis of the results.\nQ8: Author should provide the detail discussion on the multiple reflection effect in this\nstudy.\nReply: Thank you for the suggestion. In response to this comment, the revised version\nincludes a discussion of multiple reflections.\nPage 6, Paragraph 3, Line 22-31 in the revised manuscript:\nAdditionally, non-uniform electric field distribution is observed in latticed surfaces\nwhen subjected to an external electric field, leading to higher power loss density at the\nlattice (Fig. S23), suggesting that electromagnetic waves are not only subjected to\nreflection loss but also diffuse reflection on surfaces with structures. Simulations of the\nEF direction in the y-z plane (Fig. 2G and S24) demonstrates that the direction of the\nelectric field of the lattice structure changes at the raised lattice. This indicates that the\nformation of the raised structure on the surface facilitates the enhancement of diffuse\nEM wave scattering, while influencing the electric field distribution at the surface. The\npotency of the raised lattice structure can be explained by the bandwidth of GHz\nfrequency electromagnetic waves and its interaction with micrometer scale regular\nstructures through Rayleigh scattering27-30.\nQ9: The original and retained values of EMI shielding effectiveness (SE) should be\nincluded in the text to demonstrate the long-term stability of the latticed MXene\nstructure for better understanding.\nReply: Thanks you for the excellent advice. In response to this comment, the revised\nversion includes the original and retained values of the EMI shielding effectiveness\n(SE). Tables R4, R5 and R6 have been added to tables S10, S11 and S12 in the\nsupplementary information.\nTable R4 (Supplementary Table 10 in the revised supplementary information) EMI\nSE of latticed MXene films under different tensile strains.\nTensile strain (%) Retained EMI SE (dB)\n0 81.5\n2% 81.5\n5% 81.3\n8% 81.0\n11% 80.3\nTable R5 (Supplementary Table 11 in the revised supplementary information) The\noriginal and retained values of EMI SE for latticed MXene films under different\ntensile strains.\nDifferent harsh\nOriginal EMI SE (dB) Retained EMI SE (dB)\nconditions\nUltrasound, 2 h 81.5 79.1\nUltrasound, 6 h 81.5 77.7\n300 °C, 24 h 81.5 78.5\n-196 °C, 24 h 81.5 80.0\npH=1, 24 h 81.5 80.0\nThermal shock, 50 times 81.5 77.8\nTable R6 (Supplementary Table 12 in the revised supplementary information) The\nretained EMI SE of latticed MXene, flat MXene, and MXene-VAF films after\nexposure to environments at 40°C and 60-80% humidity for different durations.\nSample Time (months) Retained EMI SE (dB)\n0 81.5\n1 80.9\nLatticed MXene 2 76.5\n3 73.2\n4 70.2\n0 81.5\nFlat MXene 1 72.9\n2 60.9\n3 56.9\n4 50.9\n0 81.7\n1 69.9\nMXene-VAF 2 58.9\n3 49.9\n4 45.9\nIn response to this comment, Table R4, R5 and R6 have been added to Table S10, S11\nand S22 in the supporting information.\nQ10: The term \"MXene/PI films\" should be clarified: does it refer to latticed MXene\nor the entire MXene composite? Similarly, the title of Figure 4 should reflect this\nclarification.\nReply: Thanks you for pointing out the lack of clarity regarding the term “MXene/PI\nfilms”. MXene/PI film refers to the entire MXene composite material. In this work,\nMXene forms a lattice structure on the surface of PI. The testing and characterization\nconducted in this study were on the MXene/PI composite film. For the EMI shielding\nperformance, the EMI shielding performance is provided by latticed MXene, while PI\nand PET polymer substrates have insignificant EMI shielding performance (Fig. R1).\nTherefore, it is named as latticed MXene. The third figure reveals the excellent\nmechanical properties and the stability under extreme environments, which are\nattributed to the surface lattice structure and the PI substrate. The fourth figure\ndemonstrates the hydrophobic property and the anti-icing property, which are provided\nby MXene with a lattice structure. The Joule heating ice removal property is attributed\nto the surface lattice structure and the PI substrate.\nIn response to this comment, the section title for Part 3 has been revised to “Joule\nheating and deicing properties” to maintain consistency with the heading of Part 4.\nQ11: In the synthesis section, the authors mention using the HCl/LiF method for\nfabricating MXene. However, it is unclear why sonication is necessary, as this process\nis commonly used for synthesizing single-layer MXene.\nReply: Thanks you for the excellent question. Firstly, we etched the aluminum layer in\nHCl and LiF to synthesize multilayer MXene. Then, through ultrasonication treatment,\nMXene was delaminated to obtain single/few-layer MXene nanosheets. Subsequently,\nthe single/few-layer MXene slurry was rapidly concentrated to proceed to the next step\nof blade coating. Studies have shown that the thickness of a single layer of MXene is\nonly 1.5-2.0 nm. The single layer MXene solution obtained after ultrasonic oscillation\nis strictly referred to as few-layer MXene, rather than ideal single-layer MXene, which\nis determined jointly by the inherent properties of the and the material and the\npreparation process. The surface of the MXene layers contains a large number of\nunsaturated bonds (such as -O, -OH, -F termination groups), resulting in an extremely\nhigh surface energy (>100 mJ/m²). To reduce energy, the layers will spontaneously\nstack through van der Waals forces, forming a few-layer structure of 2-5 layers. The -\nOH terminations on the surface and water molecules or -OH terminations of adjacent\nlayers form hydrogen bond networks (energy≈20 kJ/mol), further promoting interlayer\nadsorption. In summary, the thermodynamic instability of single-layer MXene leads to\nthe spontaneous stacking of MXene nanosheets.\nR11. AFM image and of the few-layer Ti C T MXene flakes.\n3 2 x\nThe AFM image of the MXene after ultrasonication is presented in Fig. R11. It was\nfound that the few-layer MXene we prepared was similar to that reported in the\nliterature, as monolayer MXene tended to restack. Therefore, to be rigorous, the MXene\nprepared after ultrasonication was thus referred to as few-layer MXene.\nQ12: References 19 and 33 appear to be identical and should be revised accordingly.\nReply: Thanks you for pointing out this error. We reviewed this error and changed the\n33 references in the article to 19. The subsequent reference numbers were then\nsequentially decreased by 1.\nQ13: The authors are encouraged to provide detailed discussions for all figures and\nsubfigures in the supporting information section to enhance the overall clarity and\ncompleteness of the manuscript.\nReply: Thanks you for your invaluable input. We have provided detailed discussions\nfor each SI figure in the supporting information section, and the changes made have\nbeen highlighted in the supporting information."}, {"round": 2, "reviewer_comments": {"reviewer_2": "Nature Communication\nManuscript Number: nature communctaion-5943640\nRecommendation: Major Revision\nAlthough the authors have revised the manuscript as suggested, several critical issues remain. There are still unclear points\nregarding the main advantages of the lattice-structured MXene in terms of properties compared to the reported literature.\nIn addition, the EMI shielding and Joule heating performance comparisons are still very limited. The authors need to address\nthe following comments:\n1. The novelty of this work remains unclear. The enhanced EMI shielding performance largely results from the improved\nelectrical conductivity of the lattice-structured MXene. However, achieving high EMI shielding effectiveness (SE) through\nincreased conductivity is already well established in the literature. No fundamentally new mechanism has been introduced.\nSimilar strategies that combine surface patterning with conductivity enhancement have already been reported, e.g., Angew.\nChem. Int. Ed. 2022, 61, e202201323. The authors should clarify the novelty of their approach and how it differs from\nexisting methods.\n2. The authors compare the EMI performance with limited literature. However, a more comprehensive benchmarking against\nstate-of-the-art MXene shielding materials, particularly those with thicknesses below 20 μm, is missing. The authors should\ninclude a plot of EMI SE versus thickness for pristine MXene reported in the literature in Figure 1f, along with the\ncorresponding numerical data in a supplementary table. This will enable readers to better understand how the lattice-\nstructured MXenes (MXene/PI) in this study compare to previously reported pristine MXene films and allow for a more robust\nevaluation of their EMI performance.\n3. Authors should provide AFM images and thickness profiles of the pristine PAA film (Supplementary Figure 7a) and PI film\n(Supplementary Figure 7c). This is necessary to assess whether any wrinkles form on the PI film after drying. If the pristine\nPI film does not exhibit wrinkles, it raises concerns about the interfacial interactions between MXene and PI. In such a\nscenario, the adhesion at the MXene/PI interface may be significantly weakened upon drying, potentially leading to\ndelamination or peeling.\n4. For Figure S34, the authors should provide a video showing the immersion of the lattice MXene in liquid nitrogen,\nfollowed by its bendability after removal. MXene films typically become brittle under such conditions and are prone to\nbreaking upon bending. Including this video would help validate the mechanical flexibility and structural integrity of the\nlattice MXene under extreme conditions.\n5. In Figure 4a, the temperature was measured using an IR camera. However, due to the low IR emissivity of MXene, this\nmethod may not provide accurate surface temperature values. The authors should determine the actual IR emissivity of their\nsamples and/or use a contact-mode thermocouple for verification. Additionally, images of the samples after Joule heating at\n6. In Figure 4d, it is unclear why the lattice MXene exhibits higher hydrophobicity and longer icing time. How does the\nwrinkled structure enhance hydrophobicity? Additionally, what is the significance of the ice sliding off the film at a 20° tilt\nunder 3 V Joule heating? Furthermore, the authors should also compare the Joule heating performance of the vacuum-\nfiltered and flat MXene films at the same voltage. Are the temperature values comparable?"}, "author_response": "Response to Reviewer 2’ Comments\nReviewer 2：\nComments: Although the authors have revised the manuscript as suggested,\nseveral critical issues remain. There are still unclear points regarding the main\nadvantages of the lattice-structured MXene in terms of properties compared to the\nreported literature. In addition, the EMI shielding and Joule heating performance\ncomparisons are still very limited.\nReply: We sincerely thank you for your time and for providing these additional\nconstructive comments, which have helped us further improve our manuscript. We have\nconducted additional analyses and comparisons to better highlight the advantages of\nour work. Please find our point-by-point responses below.\nQ1: The novelty of this work remains unclear. The enhanced EMI shielding\nperformance largely results from the improved electrical conductivity of the\nlattice-structured MXene. However, achieving high EMI shielding effectiveness\n(SE) through increased conductivity is already well established in the literature.\nNo fundamentally new mechanism has been introduced. Similar strategies that\ncombine surface patterning with conductivity enhancement have already been\nreported, e.g., Angew. Chem. Int. Ed. 2022, 61, e202201323. The authors should\nclarify the novelty of their approach and how it differs from existing methods.\nReply: We sincerely thank the reviewer for this insightful comment. To achieve ultra-\nthin thickness without compromising shielding performance, it remains a major\nchallenge in this field. To attain high shielding effectiveness with minimal thickness, it\nis imperative to propose new shielding mechanism. Here, we achieved an ultrathin\nMXene film (2.8 μm) with a patterned lattice structure, exhibiting the ultrahigh EMI.\nThe unique shielding enhancement mechanism of this structure lies in its dual capability:\non one hand, the interlaced lattice provides additional conductive pathways, thereby\nenhancing the reflection of electromagnetic waves (EMWs); on the other hand, the\nuniform micro-nano lattice induces Rayleigh scattering, which further strengthens the\nabsorption of EMWs (Figure R1).\nFigure R1. (A) Finite element simulated current density map and (B) electric field\ndirection maps of lattice-structured films at 10 GHz. (C) Schematic of EMI shielding\nmechanism in the lattice structured MXene film.\nThere have been some notable studies in this field, such as Angew. Chem. Int. Ed.\n2022, 61, e202201323. That work achieved exceptional EMI shielding of 58 dB\nrequiring a thickness of 5 μm, by introducing extensive Ti vacancies via chemical\netching, which generated micro-wrinkles and enhanced absorption. Here, we make a\ngreat breakthrough to achieve nearly similar EMI SE with only 56% of the thickness.\nThe novelty of our work is summarized as following:\n(i) Fabrication approach: Our lattice pattern was achieved through uniform thermal\nshrinkage of MXene on a polymer surface, whereas Angew. Chem. Int. Ed. 2022, 61,\ne202201323 utilized chemical etching. Our approach has the great advantage of\ncontrolling the wrinkled pattern for the different thickness films.\n(ii) Pattern structures: We obtained an interlaced lattice architecture, resembling a\ncrosshatched grid pattern. In contrast, the aforementioned study produced a randomly\nwrinkled surface with micro-fold structures. This uniform lattice architecture is vital to\nachieve the ultrathin yet high-performance EMI.\n(iii) Shielding mechanisms: The interconnected ordered lattice in our film provides\nadditional conductive pathways, significantly enhancing the reflection of\nelectromagnetic waves (EMWs) and Rayleigh scattering. The randomly formed micro-\nwrinkles in Angew. Chem. Int. Ed. 2022, 61, e202201323 makes difficult to form\neffective conductive networks, thus resulting in limited improvement in electrical\nconductivity.\nTable R1 (Table S1 in Supplementary Information). Thickness and EMI SE\nvalues of MXene shielding materials.\nMaterial type Thickness (μm) EMI SE (dB) Ref.\nWrinkled MXene films 5.0 58.0 1\nMo Ti C T 3.5 23.0\n2 2 3 x\nTi C T 8.0 26.0 2\n3 2 x\nTi C T 11.0 57.0\n3 2 x\nTi CT 11.0 50.0\n2 x\nV CT 12.0 46.0\n2 x\nNb CT 10.0 15.0\n2 x\nTi Nb Ct 14.0 50.0\n1.6 0.4 x\nNb V CT 12.0 36.0\n0.4 1.6 x\n3 2 x\nTi CNT 10.0 55.0\n3 x\nMo TiC T 9.0 21.0\n2 2 x\nNb C T 11.0 26.0\n4 3 x\nMo Ti C T 13.0 37.0\n2 2 3 x\nMXene/BC 4.0 37.3 4\nMXene/PA 20.0 38.9 5\n1.0 29.0\nMXene Foam 6\n6.0 53.0\nMXene/rGO film 15.0 47.0 7\nAg NWs-MXene-Ag NPs 20.0 71.0 8\nMXene/Fe O @CNTs/TOCNF 18.0 66.0 9\n3 4\nHA/MXene@polypyrrole 14.9 22.6 10\nNaOH-treated Ti C T MXene 16.0 49.0 11\n3 2 x\n0.7 38.6\n1.5 45.7\nLatticed MXene 2.8 50.4 This work\n7.0 65.7\n17.0 81.5\nWe have included a comparison with relevant literature, including Angew. Chem.\nInt. Ed. 2022, 61, e202201323, in the manuscript to more clearly demonstrate the novel\nmechanism of shielding performance enhancement enabled by the lattice-patterned\nstructure.\nPage 6, Paragraph 3, Line 32 in the revised manuscript:\nPrevious works indicated that wrinkled structures can effectively enhance\nelectromagnetic wave absorption, with a 5 μm thick wrinkled MXene film for a\nshielding effectiveness of 58 dB31. Here, we achieved an ultrathin MXene film (2.8 μm)\nwith a patterned lattice structure, exhibiting the nearly similar ultrahigh EMI SE. The\nunique shielding enhancement mechanism of our lattice architecture lies in its ability\nto provide additional conductive pathways through the crossed lattices, thereby\nenhancing the overall electrical conductivity of the film. Simultaneously, the uniform\nmicro/nano lattice configuration induces Rayleigh scattering, which further augments\nelectromagnetic wave absorption. The synergistic enhancement of both reflection and\nabsorption results in a significantly higher total shielding effectiveness in the lattice-\npatterned MXene compared to other surface-patterned films reported in the field13, 31,\n32.\nQ2: The authors compare the EMI performance with limited literature. However,\na more comprehensive benchmarking against state-of-the-art MXene shielding\nmaterials, particularly those with thicknesses below 20 μm, is missing. The authors\nshould include a plot of EMI SE versus thickness for pristine MXene reported in\nthe literature in Figure 1f, along with the corresponding numerical data in a\nsupplementary table. This will enable readers to better understand how the lattice-\nstructured MXenes (MXene/PI) in this study compare to previously reported\npristine MXene films and allow for a more robust evaluation of their EMI\nperformance.\nReply: We sincerely thank the reviewer for this insightful and constructive comment.\nWe completely agree that a more comprehensive benchmarking against state-of-the-art,\nultra-thin pristine MXene films is crucial to better highlight the advantages of our\ndesigned MXene/PI lattice structure.\nBased on the valuable suggestions from the reviewers, we have added comparisons\nwith state-of-the-art MXene shielding materials in this study. The related references are\npresented in Table R1 and have been incorporated into Figure 1F (Figure R2) and the\nTable S1. As clearly demonstrated in the revised Figure 1F, our lattice-structured\nMXene exhibits electromagnetic interference shielding effectiveness superior to nearly\nall previously reported EMI shielding films of the same type at comparable thicknesses.\nThis comparison underscores the advancement of our fabrication strategy, which\nutilizes uniform polymer shrinkage to induce wrinkling and form regularly structured\nMXene lattices, in achieving exceptional performance in the field of ultra-thin and\nhighly efficient electromagnetic shielding.\nFigure R2 (Figure 1F in manuscript). Comparison of the EMI shielding performance\nof the lattice-structured MXene with other recently reported EMI shielding materials.\nPage 5, Paragraph 2, Line 18 in the revised manuscript:\nThe lattice-structured MXene exhibits a superior EMI shielding performance,\nsurpassing most previously reported works, particularly in the field of ultra-thin EMI\nshielding films, as shown in Fig. 1F and Table S1.\nQ3: This is necessary to assess whether any wrinkles form on the PI film after\ndrying. If the pristine PI film does not exhibit wrinkles, it raises concerns about\nthe interfacial interactions between MXene and PI. In such a scenario, the\nadhesion at the MXene/PI interface may be significantly weakened upon drying,\npotentially leading to delamination or peeling.\nReply: We thank the reviewer for this excellent suggestion. We agree entirely that\nproviding AFM data for the pristine films is necessary to rule out any ambiguity\nregarding the origin of the wrinkling and to properly assess the interfacial adhesion.\nIn response to this comment, we have now provided the AFM height images and\ncorresponding thickness profiles of the pristine PAA film and the pristine PI film\n(Figure R3).\nFigure R3 (Figure S7 in Supplementary Information). (A ) 2D AFM (A ) 3D AFM\n1 2\nimages and (A ) height profiles of the PAA. (B ) 2D AFM (B ) 3D AFM images and\n3 1 2\n(B ) height profiles of the PI.\nare smooth and completely free of wrinkles. This observation leads to a key conclusion\nthat the wrinkles observed on the MXene/PI film are not inherent to the PI substrate,\nbut are exclusively formed due to compressive stresses introduced by the MXene layer\nduring the drying process. The fact that the pristine PI film itself is smooth demonstrates\nthat the wrinkling is a direct result of strong interfacial interactions between MXene\nand PI.\nHydrogen bonding interactions between the polymer and MXene were established\neven before thermal treatment. During the heating process, partial dissociation of the\noriginal hydrogen bonds connecting PAA and MXene occurred. Following the\nconversion of PAA to PI via dehydration-induced cyclization, new van der Waals\ninteractions and hydrogen bonds were formed between the -OH groups on the MXene\nnanosheets and the C=O groups in the PI molecular chains15. The strong resistance of\nMXene to delamination from the polyimide (PI) surface was confirmed by the peel\nstability and ultrasonication test results presented in Section 3 (Figures S30 and S31 in\nSupplementary Information) of this paper. Furthermore, we have provided a\nsupplementary video (Video S1 in the Supplementary Information) demonstrating the\nsonication process of MXene/PI, MXene/PET, and MXene-VAF films. The video\nclearly shows that for the MXene/PET film, the solution begins to turn cloudy after 1 s\nof sonication, accompanied by the diffusion of MXene into the aqueous solution. For\nthe MXene-VAF material, cracking is observed after approximately 35 s of sonication,\nfollowed by gradual clouding of the solution. In contrast, no detachment of MXene is\nobserved for the MXene/PI film even after 6 hours of sonication, and the aqueous\nsolution remains clear (Fig. S32 in the Supplementary Information).\nPage 9, Paragraph 2, Line 16 in the revised manuscript:\nVideo S1 clearly shows that for the MXene/PET film, the solution begins to turn cloudy\nafter 1 s of sonication, accompanied by the diffusion of MXene into the aqueous\nsolution. For the MXene-VAF film, cracking is observed after approximately 35 s of\nsonication, followed by gradual clouding of the solution. In contrast, no detachment of\nMXene is observed for the MXene/PI film even after 6 hours of sonication, and the\naqueous solution remains clear (Fig. S32).\nQ4: For Figure S34, the authors should provide a video showing the immersion of\nthe lattice MXene in liquid nitrogen, followed by its bendability after removal.\nMXene films typically become brittle under such conditions and are prone to\nbreaking upon bending. Including this video would help validate the mechanical\nflexibility and structural integrity of the lattice MXene under extreme conditions.\nReply: We sincerely thank the reviewer for this valuable suggestion. We agree that a\ndirect visual demonstration is the most compelling way to showcase the exceptional\nmechanical flexibility and structural integrity of our lattice MXene architecture under\nextreme cryogenic conditions.\nAs requested we have now provided a video (Video S2 in Supplementary\nInformation) demonstrating the entire process. The free-standing lattice MXene film\nwas immersed in liquid nitrogen and repeatedly folded for over one minute to ensure\ncomplete thermal equilibrium. It was then removed and immediately subjected to\nrepeated bending and folding. All procedures were performed without any observable\npeeling or fracture of the MXene layer.\nThis video unequivocally demonstrates that our lattice MXene structure retains its\noutstanding flexibility even at -196 °C, which is a stark contrast to the typical brittleness\nobserved in conventional, dense MXene films under such conditions.\nPage 9, Paragraph 3, Line 28 in the revised manuscript:\nVideo S2 demonstrates that MXene/PI films remain capable of withstanding repeated\nbending and folding without fracture even after removal from liquid nitrogen\nimmersion, highlighting the application potential of latticed MXene in cryogenic\nenvironments.\nQ5: In Figure 4a, the temperature was measured using an IR camera. However,\ndue to the low IR emissivity of MXene, this method may not provide accurate\nsurface temperature values. The authors should determine the actual IR\nemissivity of their samples and/or use a contact-mode thermocouple for\nverification. Additionally, images of the samples after Joule heating at 4 V, 5 V, 6\nV, and 7 V should be included to evaluate any morphological or structural changes\ninduced by heating.\nReply: We thank the reviewer for raising these critical points regarding temperature\nmeasurement accuracy and post-heating morphology. We agree that the low IR\nemissivity of MXene can pose a challenge for non-contact thermography. We have now\nperformed additional experiments to address both concerns thoroughly.\nIn direct response to the reviewer's suggestion, we performed a simultaneous\ncalibration of the IR camera reading using a fine-wire K-type thermocouple placed in\ndirect contact with the surface of the MXene film during Joule heating (Figure R4).\nFigure R4 (Figure S38 in Supplementary Information). (A) Surface temperature of the\nlattice MXene film measured by a thermocouple during Joule heating. (B) The\ninfrared emissivity of MXene/PI films.\nIn direct response to the reviewer’s suggestion, we have provided the infrared\nemissivity values for both latticed MXene/PI film, with the results presented in Figure\nR4B. Additionally, we further measured the surface temperature of the lattice MXene\nfilm during Joule heating under various voltages. Figure R4A shows the surface\ntemperature of the lattice MXene under different voltages, as measured by a\nthermocouple thermometer. Compared with Figure 4A in the manuscript, the actual\ntemperature measured by the thermocouple and the data obtained from the infrared\ncamera are nearly identical. The reason for this agreement is that the emissivity setting\nin the infrared camera was adjusted to match that of MXene before temperature\nmeasurement, meaning the infrared camera was specifically calibrated for our material.\nThis calibrated emissivity value effectively compensates for the intrinsically low\nemissivity of MXene, enabling the infrared camera to accurately capture the surface\ntemperature.\nPage 10, Paragraph 2, Line 10 in the revised manuscript:\nThe temperature measured by infrared imaging varies from 34.7 to 397.0 °C, showing\nstrong agreement with thermocouple readings (Fig. 4A and S38).\nFigure R5 (Figure S41 in Supplementary Information). (A) Optical photos of\nMXene/PI films under heating at different voltages. (B) SEM images of MXene/PI\nfilms under heating at different voltages.\nAs requested we have supplemented the optical photographs of the MXene/PI film\nunder voltages ranging from 1 to 8 V (Figure R5A). No significant morphological\ndegradation such as cracking delamination or burning was observed at voltages from 1\nto 7 V while combustion occurred at the connection between the film and the metal clip\nat 8 V due to excessive heat. SEM images of the lattice MXene after Joule heating at 1\nV to 7 V are presented in Figure R5B. These images reveal negligible changes in the\nsurface morphology of the lattice MXene after being subjected to voltages of 1-7 V\ncompared to its original state. This result demonstrates the exceptional electro-thermal\nstability and structural integrity of our lattice MXene film under high electrical load.\nPage 12, Paragraph 1, Line 8 in the revised manuscript:\nThe EMI SE of the latticed MXene shows no significant change after several Joule\nheating deicing cycles (Fig. S40), which can be attributed to the excellent\nelectrothermal stability and structural integrity of the lattice-structured MXene film\nunder high electrical load (Fig. S41).\nQ6: In Figure 4d, it is unclear why the lattice MXene exhibits higher\nhydrophobicity and longer icing time. How does the wrinkled structure enhance\nhydrophobicity? Additionally, what is the significance of the ice sliding off the film\nat a 20° tilt under 3 V Joule heating? Furthermore, the authors should also\ncompare the Joule heating performance of the vacuum-filtered and flat MXene\nfilms at the same voltage. Are the temperature values comparable?\nReply: We thank the reviewer for these insightful questions, which allow us to further\nclarify the mechanisms behind the superior performance of our lattice MXene film. We\nhave conducted additional experiments and provided deeper explanations as detailed\nbelow.\nThe enhanced hydrophobicity of the wrinkled structure can be explained by the\nCassie-Baxter state. The Cassie-Baxter equation is as follows:\ncos𝜃 =f cos𝜃 + f cos𝜃 (1)\n𝑐 1 1 2 2\nAccording to Figure R6, the lattice was modeled as gridlines with a width of 2.5\nμm. The area fraction of the droplet in contact with the latticed MXene, f₁, is given by:\n2.51050\nf = =0.5, f =1- f =1-0.5=0.5\n1 2 1\n5050\n𝜃 represents the water contact angle of water droplets on the lattice MXene, 𝜃\n𝑐 1\nrepresents the water contact angle of water droplets on the planar MXene, and 𝜃\n2\nrepresents the contact angle of air. Among them, 𝜃 = 50.6°, 𝜃 = 180°.\n1 2\ncos𝜃 =0.5cos50.6°+0.5cos180°=-0.18\n𝑐\n𝜃 =100.4°\n𝑐\nFigure R6. (A) The cross-sectional equivalent diagram of the latticed MXene. (B)\nSEM image with different magnifications of the latticed MXene.\nAccording to the Cassie-Baxster model, the water contact angle of the lattice-\npatterned MXene is significantly higher than that of the flat structure (50.6°),\ndemonstrating that the micro-lattice itself is a primary factor enhancing hydrophobicity.\nFurthermore, heat treatment removed polar groups from the MXene surface, further\nenhancing its hydrophobicity. In summary, the lattice structure enhances\nhydrophobicity mainly by trapping air pockets to establish a stable Cassie-Baxter state.\nThe prolonged icing time is a direct consequence of this air layer, which provides\nthermal insulation. Additionally, our thermal treatment chemically enhanced the\nintrinsic hydrophobicity of MXene, which works synergistically with the physical\nstructure to ultimately achieve a contact angle of 125° and delayed ice formation.\nPage 11, Paragraph 1, Line 10 in the revised manuscript:\nThe enhancement of hydrophobicity in the latticed MXene is attributed to the combined\neffect of its unique lattice-patterned structure and the removal of surface polar groups\nthrough heat treatment.\nPage 11, Paragraph 1, Line 16 in the revised manuscript:\nThe delayed icing is attributed to the wrinkled morphology of the lattice structure,\nwhich facilitates the formation of a stable air cushion beneath the water droplet. This\nair layer reduces solid-liquid contact and effectively impedes thermal transfer.\nThe significance of the ice-shedding experiment at a 20° tilt under 3 V Joule\nheating lies in its demonstration of a synergistic passive-active de-icing strategy, which\nis highly desirable for practical applications. The combination of low voltage and a\nminimal tilt angle means that even a slight inclination of 20° is sufficient for gravity to\novercome the significantly weakened ice adhesion force, resulting in complete ice\nremoval. This confirms an energy-efficient and effective de-icing capability, as the\nprocess requires neither high voltage nor mechanical force. The practical implications\nof this feature are substantial, particularly in applications where energy efficiency,\nlightweight design, and autonomous operation are critical. For example, this technology\ncould be applied to aircraft wings and wind turbine blades to prevent ice accumulation\nwithout demanding high energy consumption or mechanical intervention. Similarly, it\ncould be integrated into solar panels, power transmission equipment, and outdoor\nsurveillance systems to ensure reliable performance in cold and icy environments. The\nability to achieve rapid de-icing at low tilt angles and low voltages also makes it suitable\nfor applications with spatial or structural constraints, such as drones and automotive\nsensors. By enabling efficient ice removal without complex hardware or significant\nenergy input, this passive-active de-icing strategy offers a practical solution for\nmaintaining operational safety and functionality across a wide range of industrial and\nenvironmental conditions.\nPage 12, Paragraph 1, Line 4 in the revised manuscript:\nThis demonstrates that latticed MXene exhibit low ice adhesion and efficient de-icing\ncapabilities under low voltage and slight inclination, indicating their energy-saving\npotential and practical applicability in anti-icing and de-icing systems.\nAs requested, we have now compared the Joule heating performance of latticed\nMXene film, the vacuum-filtered MXene film and flat MXene film under the same\napplied voltages. The resulting temperature data is presented in Figure R7A.\nFigure R7 (Figure S37 in Supplementary Information). (A) The temperatures of\nMXene/PI, MXene/PET and MXene-VAF films at different voltages. The IR thermal\nimages of the (B) MXene-VAF and (C) MXene/PET films at different driving voltages.\nThe temperature of the MXene-VAF film increases with applied voltage in the\nrange of 1-3 V. However, when the voltage further increases, the MXene-VAF fractures\ndue to excessive heating (Figure R7B). In contrast, the temperature of the MXene/PET\nfilm shows no significant change with increasing voltage. This is because the flat\nMXene layer delaminates from the PET substrate upon mild Joule heating, preventing\nthe formation of a continuous conductive pathway (Figure R7C). In contrast, the lattice-\nstructured MXene/PI film exhibits stable and controllable Joule heating performance\neven at higher voltages. This can be attributed to the strong interfacial bonding between\nthe MXene and the PI substrate, which prevents delamination and maintains electrical\ncontinuity under thermal stress. Furthermore, the outstanding thermal stability of the PI\nsubstrate (as demonstrated in Figure 33 in supporting information) enables the hybrid\nfilm to withstand elevated temperatures without structural degradation. As a result, the\ntemperature of the MXene/PI film increases steadily and reversibly with applied voltage,\nhighlighting its potential for reliable operation in electrothermal applications. The\ncombination of robust interfacial adhesion, high thermal tolerance, and consistent\nelectrical performance underscores the advantage of the MXene/PI design over MXene-\nVAF and MXene/PET film.\nPage 10, Paragraph 2, Line 5 in the revised manuscript:\nIn contrast, the MXene-VAF fractures at 4 V owing to overheating, while the\ntemperature of the MXene/PET film shows no significant change with increasing\nvoltage, owing to the delamination between MXene and PET during heating (Fig. S37).\nIn response to the reviewer’s comment, we have supplemented the comparison with\nstate-of-the-art materials possessing Joule heating performance, as newly provided in\nTable R2. Additional supporting references are included in Table S13 of the\nSupplementary Information and Figure 4C of the manuscript.\nTable R2 (Table S13 in Supplementary Information). Joule thermal properties\ncomparison of MXene/PI films and other materials reported in literature.\nMaterial type Voltage (V) Temperature (°C) Ref.\nMXene-GNs/ANF 4 160.0 13\nMXene@CGA/Ag NPs 4 114.1 14\nAMLM-PM foam 5 42.5 15\nPPF/TCT composite 5 104.8 16\nLiquid metal/poly(urethane-\n2 61.3 17\nurea) composite\nMXene/PANI/PDA 5 94.0 18\nCMOF/SBR/CNT/SBR 10 152.0 19\nCarbon fabrics of Kevlar\n5 180.0 20\nfibres\n3 30.4\nCarbon black/graphene/nickel 5 43.2\n21\npolyimide foam 7 64.8\n9 89.2\nES-welded AgNW network 4 80.0 22\n1 34.7\n2 64.1\n3 107\nLatticed MXene 4 173.6 This work\n5 235.2\n6 311\n7 397\nReferences\n1. Ying, M. F. et al. Wrinkled Titanium Carbide (MXene) with Surface Charge\nPolarizations through Chemical Etching for Superior Electromagnetic Interference\nShielding. Angew. Chem. Int. Ed. 61, e202201323 (2022).\n2. Shahzad, F. et al. Electromagnetic interference shielding with 2D transition metal\ncarbides (MXenes). Science 353, 1137-1140 (2016).\n3. Han, M. K. et al. Beyond Ti C T : MXenes for electromagnetic interference\n3 2 x\nshielding. ACS nano, 14, 5008-5016 (2020).\n4. Wan, Y. Z. et al. Ultrathin, strong, and highly flexible Ti C T MXene/bacterial\n3 2 x\ncellulose composite films for high-performance electromagnetic interference\nshielding. ACS nano 15, 8439-8449 (2021).\n5. Cheng, Z. et al. Multifunctional MXene-based composite films with simultaneous\nterahertz/gigahertz wave shielding performance for future 6G communication. J.\nMater. Chem. A. 11, 5593-5605.\n6. Liu, J. et al. Hydrophobic, Flexible, and Lightweight MXene Foams for High-\nPerformance Electromagnetic-Interference Shielding. Adv Mater. 29, 1702367\n(2017).\n7. Tang, X. W. et al Ultrathin, flexible, and oxidation-resistant MXene/graphene\nporous films for efficient electromagnetic interference shielding. Nano Res. 16,\n1755-1763 (2023).\n8. Qu, Y. F. et al. 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Highly stretchable liquid metal/poly(urethane-urea) composite with\nself-healing ability for electromagnetic interference shielding. Compos Part B-Eng.\n306, 112808 (2025).\n18. Chen, H. L. et al. Advanced Textiles Inspired by Leaf Structure for Enhanced\nPersonal Electromagnetic Protection and Thermal Management. ACS Appl. Nano\nMater. 8, 7140-7153 (2025).\n19. Dehghani, A., Sambyal, P., Arjmand, M. et al. Flexible rubber-based nanocomposite\nwith superior electromagnetic interference shielding and joule heating. Carbon, 238,\n120180 (2025).\n20. Singh, K., Baheti, V. et al. EMI shielding and joule heating applications of woven\nand nonwoven activated carbon fabrics of Kevlar fibres. Anal. Appl. Pyrolysis. 188,\n107041 (2025).\n21. Wang, Y. G. et al. Multifunctional rigid polyimide foams with outstanding EMI\nshielding and wave absorption via densification strategy. J. Mater. Sci. Technol. 227,\n155-163 (2025).\n22. Zhu, C. C. et al. Facile electrospray nanowelding process for high-performance and\ntailored silver nanowire networks. Appl. Surf. Sci. 689, 162465 (2025)."}, {"round": 3, "reviewer_comments": {"reviewer_2": "The authors have addressed the reviewers' comments thoroughly and effectively. Therefore, I recommend the acceptance of this paper."}, "author_response": ""}]

Decision letter