Near‐Infrared Light‐Responsive and Programmable Thermosalient Crystal‐Based MXene‐Polymer Multilayers Composites as Water‐Surface Bionic Insects

The growing demands for sustainable energy and rapid advances in bionic engineering have led to multi‐dimensional evaluation criteria for advanced functional materials, including high‐energy conversion efficiency, precisely controllable actuation, etc. Nevertheless, how to achieve an optimal balance among these critical parameters is still challenging. In this work, we successfully synthesized a novel thermosalient crystal‐based composite material based on a hybrid strategy that combines the complementary properties of MXene and thermosalient crystals. This composite material enables remote actuation under near‑infrared (NIR) light irradiation and allows precise control over its actuation dynamics through a dual‑approach involving pre‐programming and photomodulation. Quantitative analysis reveals that the composite actuator exhibits superior performance compared to many conventional actuators, achieving a widely tunable maximum output force (2.9 × 10 −3 –2.9 × 10 −2 N), force density (3.13 × 10 6 –3.95 × 10 7 N m −3 ) and broadly tunable work density (1.4 × 10 2 –3.91 × 10 5 J m −3 ). Remarkably, the novel composite material successfully completed complex bioinspired motions including self‐spinning, movement along arc‐ or spiral‐shaped paths, and even programmable path navigation, based on the synergistic interplay of the photothermal Marangoni effect and the crystal's inherent thermosalient strain. This work establishes a new paradigm for developing high‐performance, remotely and precisely controllable light‐driven robots and smart actuators.