Dual-crosslinked MXene/CNT composite film for fast and programmable humidity-responsive actuation

The development of flexible materials with green actuation, rapid responsiveness, and environmental adaptability is vital for next-generation intelligent actuators. Here, we report a humidity-responsive composite film based on the synergistic assembly of agarose (AG), Ti₃C₂Tₓ MXene, and aminated multi-walled carbon nanotubes (MWCNTs-NH₂). Dual crosslinking with Ca²⁺ and glutaraldehyde (GA) yields a dense, stable, multiscale network (AMC-CG) that enhances structural integrity and water transport. The AMC-CG film exhibits excellent thermal stability and mechanical strength. Under a 35 % humidity gradient, it achieves a maximum bending angle of 166.99°, a response speed of 282.81° s⁻¹ , and a recovery speed of 42.96° s⁻¹ , maintaining performance over 500 cycles. It also shows strong anti-swelling behavior in pH-extreme solutions and retains actuation in dusty and oily environments. A soft gripper system built with AMC-CG enables autonomous object manipulation in confined spaces, highlighting its low-power, programmable, and eco-friendly potential. and expanding the application of humidity-responsive actuators toward microoperation devices and flexible actuation systems.