Bioinspired Flexible Film as Intelligent Moisture-Responsive Actuators and Noncontact Sensors

Abstract

Inspired by nature organisms, flexible moisture-responsive actuators and sensors fabricated by hydrophilic 2D materials have attracted increased demands by utilizing water in a green and renewable way. Graphene oxide (GO) and MXene have shown great potential in moisture-responsive actuators and sensors due to their superior properties and strong interaction with water. Bioinspired actuators with nacre-like structure have been successfully fabricated by anchoring MXene and GO into bacterial cellulose fibers, which exhibit excellent moisture-driven performance with superior mechanical properties and ambient antioxidation. The flexible actuator demonstrates sensitive response to moisture with intensive deformation. It is demonstrated that the moisture-responsive smart devices are able to function as an electrical switch and robotic gripper. Furthermore, a noncontact control system can also be implemented via monitoring the respiration and the humidity on the human skin surface. Devices with effective and sensitive response to solvent and temperature have also been demonstrated by the fabricated composite film. This work overcomes the shortcomings of the actuators prepared by MXene, offering a facile approach to fabricate flexible moisture-responsive actuators and sensors with wider applications.

Keywords

• MXene
• Graphene oxide
• Moisture-responsive actuators and sensors
• Nacre-like structure
• Bacterial cellulose
• Smart devices