Programmable multi-responsive MXene actuator based on micro-ridge structures

MXene (Ti₃C₂T_x), which is known for its exceptional hydrophilicity, remarkable electrical/thermal conductivity, and superior mechanical strength, has emerged as an ideal candidate for developing stimuli-responsive actuators. However, current MXene-based actuators are unable to simultaneously achieve both multiple stimuli responses and programmable deformation, which restricts their practical applications in real-world scenarios. Here, we have developed a multi-responsive MXene/paraffin wax (PW)&Fe₃O₄ actuator with shape programmability by introducing micro-ridge structures. Since the different hydrophilicity and thermal expansion characteristics between the two layers, the actuator exhibits stimuli-responsive deformations under humidity, light, and magnetic field. Additionally, by controlling the orientation of the micro-ridge structures, combined with heat-welding methods, various complex three-dimensional configurations of actuators can be programmed. As proof of concept, several smart devices, such as a biomimetic Trachelospermum jasminoides, a spiral gripper, and a maze robot, are demonstrated, offering new insights for the development of future flexible smart devices.