Cephalopod-Inspired MXene-Integrated Mechanochromic Cholesteric Liquid Crystal Elastomers for Visible-Infrared-Radar Multispectral Camouflage.

Multispectral camouflage materials that provide adaptable features across a wide spectrum, from visible light to radar frequencies, play a vital role in sophisticated multi-band electromagnetic (EM) applications. However, conventional single-band stealth is difficult to align with the growing demand for multi-band compatibility and intelligent adaptation. Herein, we report the design and synthesis of cephalopod-inspired MXene-integrated cholesteric liquid crystal elastomers (MXene-CLCEs) with multispectral camouflage capability, which was fabricated through in situ thiol-acrylate Michael addition and free-radical photopolymerization of CLCE precursor and isocyanate-mediated robust covalent chemical bonding of MXene nanocoating at the interface. The resulting MXene-CLCE exhibits dynamic structural color changes, tunable infrared radiation, and switchable microwave shielding across wide ranges upon mechanical stretching, with its infrared stealth and microwave shielding properties being realized through the reconfiguration of surface morphology from planar to cracked states via mechanical actuation. A visible-to-infrared camouflage octopus-patterned MXene-CLCE is demonstrated to achieve a stealth effect across the visible-infrared spectrum upon mechanical stretching. As an illustration, proof-of-concept pneumatic-driven octopus-inspired soft models are demonstrated, which enables dynamic visible-infrared camouflage and microwave shielding switching between two compatible states. The research herein can offer new perspectives on the development of bioinspired smart camouflage materials and their application in various emerging fields such as smart optical stealth, dynamic thermal management, and switchable electromagnetic devices.