materials like metal shrouds are heavy, bulky, and easy to corrode. [5] As a result, the development of new EMI shielding materials has become an urgent demand for material science and engineering.Carbon-based materials, like graphene [6] and carbon nanotubes, [7] have attracted much attention as promising effective EMI shielding materials due to their high conductivity, relatively low density, and corrosion resistance. Incorporating conductive fillers with polymer matrix has been developed as a feasible alternative solution for EMI shielding materials due to its tunable structure, good processability, and mechanical properties. [8][9][10] Nevertheless, despite promising advances have been achieved for carbon-based EMI shielding materials, the incorporation of polymer inevitably accompanied with deteriorated performance due to the introduction of insulating volume in conductive network. Generally, carbon-polymer composite EMI shielding materials usually require millimeter-scale thickness to achieve satisfying shielding effectiveness, which limits their applications in many areas, especially aerospace and smart microelectronic devices. It is still an enormous challenge to obtain desirable EMI shielding efficiency at a small thickness and low density. [11][12][13] Early transition metal carbides, nitrides, and carbonitrides, known as MXenes, [14] are a new class of 2D materials which have great advantages like metallic conductivity, high specific capacitance, and excellent mechanical properties. [15,16] MXenes have demonstrated promising applications in various areas including supercapacitors, [17] batteries, [18] water desalination, [19] and sensors. [20] During the synthesis of MXene, various functional groups (e.g., O, OH, and F, denoted as -T x in the chemical formula of MXenes like Ti 3 C 2 T x ) were deposited at its surface. [21] As a result, MXene presents excellent hydrophilicity and dispersity in aqueous solution, endowing it with good solution processing capability with polymer matrix. [22,23] Very recently, the application of MXene in EMI shielding has been reported. Shahzad et al. prepared Ti 3 C 2 T x film and Ti 3 C 2 T x -sodium alginate (SA) film through vacuum assisted filtration, among them pristine Ti 3 C 2 T x film exhibited a superior EMI shielding efficiency of 92 dB. [24] Sun fabricated highly conductive Ti 3 C 2 T x at polystyrene composites through electrostatic assembly of negatively charged Ti 3 C 2 T x nanoflakes on positively charged polystyrene microspheres, the obtained composite film exhibited an outstanding EMI shielding Ultrathin and high-performance electromagnetic interference (EMI) shielding materials are urgently demanded for modern microelectronic devices. 2D metal carbides (MXenes) are considered as a promising EMI shielding material due to its metallic conductivity. In this study, sodium alginate is applied as interlayer spacer for Ti 3 C 2 T x nanosheets, which not only prevents the restacking of lamella structure but also serves as building blocks for the sponge-like s...

Despite the tremendous advancement of intelligent robots, it remains a great challenge to integrate living organisms‐like multistimuli responsive actuation and excellent self‐healing ability into one single material system, which will greatly benefit and broaden the development of smart biomimetic materials. Herein, a novel self‐healable multistimuli responsive actuator is developed based on hierarchical structural design and interfacial supramolecular crosslinking. The resulting biomimetic actuator shows a record high photothermal efficiency (ηPT = 79.1%) and thermal conductivity (31.92 W m−1 K−1), and presents a superfast actuating response (near‐infrared light: 0.44 s; magnetic field: 0.36 s). In addition, the supramolecular crosslinking endows excellent self‐healing performance in both mechanical and actuating properties to the material. This biomimetic actuator with its hierarchical structure design provides great potential for various applications, such as artificial muscles, soft robotics, and biomedical microdevices.

Animal skin is a huge source of inspiration when it comes to multifunctional sensing materials. Bioinspired sensors integrated with the intriguing performance of skin‐like steady wide‐range strain detection, real‐time dynamic visual cues, and self‐healing ability hold great promise for next‐generation electronic skin materials. Here, inspired by the skins of a chameleon, cellulose nanocrystals (CNCs) liquid crystal skeleton is embedded into polymerizable deep eutectic solvent (PDES) via in situ polymerization to develop a skin‐like elastomer. Benefiting from the elastic ionic conductive PDES matrix and dynamic interfacial hydrogen bonding, this strategy has broken through the limitations that CNCs‐based cholesteric structure is fragile and its helical pitch is non‐adjustable, endowing the resulting elastomer with strain‐induced wide‐range (0–500%) dynamic structural colors and excellent self‐healing ability (78.9–90.7%). Furthermore, the resulting materials exhibit high stretch‐ability (1163.7%), strain‐sensing and self‐adhesive abilities, which make them well‐suitable for developing widely applicable and highly reliable flexible sensors. The proposed approach of constructing biomimetic skin‐like materials with wide‐range dynamic schemochrome is expected to extend new possibilities in diverse applications including anti‐counterfeit labels, soft foldable displays, and wearable optical devices.

The combination of complex perception, defense, and camouflage mechanisms is a pivotal instinctive ability that equips organisms with survival advantages. The simulations of such fascinating multi‐stimuli responsiveness, including thigmotropism, bioluminescence, color‐changing ability, and so on, are of great significance for scientists to develop novel biomimetic smart materials. However, most biomimetic color‐changing or luminescence materials can only realize a single stimulus‐response, hence the design and fabrication of multi‐stimuli responsive materials with synergistic color‐changing are still on the way. Here, a bioinspired multi‐stimuli responsive actuator with color‐ and morphing‐change abilities is developed by taking advantage of the assembled cellulose nanocrystals‐based cholesteric liquid crystal structure and its water/temperature response behaviors. The actuator exhibits superfast, reversible bi‐directional humidity and near‐infrared (NIR) light actuating ability (humidity: 9 s; NIR light: 16 s), accompanying with synergistic iridescent appearance which provides a visual cue for the movement of actuators. This work paves the way for biomimetic multi‐stimuli responsive materials and will have a wide range of applications such as optical anti‐counterfeiting devices, information storage materials, and smart soft robots.

Highly efficient and mechanically durable photothermal materials are urgently needed for solar harvesting, but their development still remains challenging. Here, inspired by the hierarchically oriented architecture of natural spider silk, an ultrarobust liquid metals (LMs)/polymer composite is presented via dynamic crosslinking based on the unique mechanical deformable characteristic of LMs. Dynamically cross‐linked core–shell structured LMs droplets can be squeezed along with the orientational crystallization of polymer chains during drawing, thus enabling LMs nanoparticles to be uniformly programmed in the rigid polyethylene nanofiber skeleton. The resultant composite exhibits an unprecedented combination of strong broad‐band light absorption (96.9–99.3%), excellent photothermal conversion ability, remarkable mechanical property (tensile strength of 283.7 MPa, which can lift 200 000 times its own weight), and long‐term structural reliability (bearing 100 000 bending cycles). A powerful and durable solar thermoelectric generator system for real‐environmental solar‐heat‐electricity conversion is further demonstrated, providing a valuable guidance for the design and fabrication of high‐performance solar‐harvesting materials.