A carbon nanofiber/Ti3C2Tx/carboxymethyl cellulose composite-based highly sensitive, reversible, directionally controllable humidity actuator and generator via continuous track-inspired self-assembly

Abstract

Harnessing water energy sources presents a compelling avenue for sustainable development. However, the development of efficient materials capable of converting moisture into mechanical motion (energy) remains a significant challenge. Herein, we draw inspiration from the agile locomotion of snakes and their distinctive tracking capabilities to engineer a novel snake-like robot/actuator. This innovative design integrates carboxymethyl cellulose (CMC), MXene, and carbon nanofibers (CNFs) into an anisotropic periodic structure, through a streamlined one-step self-assembly procedure. The resultant CNFs/MXene/CMC film-based robot/actuator exhibits remarkable sensitivity to humidity fluctuations, boasting the ability to achieve bending angles exceeding 360° at a fast-bending speed of 254.5° s⁻¹. Moreover, it demonstrates fast recovery within mere seconds under high relative humidity conditions. This as-prepared actuator holds great potential for various applications, ranging from responsive smart switches to dynamic actuating robots and efficient moisture-electric generators, presenting sustainable solutions for future developments.