Highly sensitive, reversible and directionally controllable humidity actuator and generator based on carbon nanofiber/Ti3C2TX/carboxymethylcellulose composites via continuous track-inspired self-assembly

Harnessing hydraulic energy sources is an attractive avenue for sustainable development. However, developing efficient materials that can convert moisture into mechanical motion (energy) remains a significant challenge. Here, we draw inspiration from the agile locomotion of snakes and their distinctive tracking capabilities to design a novel snake-like robot/actuator. This innovative design integrates carboxymethylcellulose (CMC), MXene, and carbon nanofibers (CNF) into an anisotropic periodic structure through a simplified one-step self-assembly procedure. The resulting CNF/MXene/CMC film-based robot/actuator exhibits remarkable sensitivity to humidity fluctuations, providing the ability to achieve bending angles exceeding 360° at a rapid bending speed of 254.5°/s. Furthermore, it demonstrates rapid recovery within seconds under high relative humidity conditions. This prepared actuator shows great potential for various applications, ranging from responsive smart switches to dynamic actuation robots and efficient humidity-controlled electric generators, presenting sustainable solutions for future developments.