Flexible MXene actuator with multi-stimulus responsiveness for biomimetic motions

Abstract

Inspired by soft-bodied organisms in nature, this study fabricated an actuator with asymmetric curvature on its two sides using an unconventional dual-flow filtration method. Owing to the significant difference in the thermal expansion coefficients between MXene and PVDF, MXene serves as the active layer while PVDF acts as the inert layer. This actuator can deform under multiple stimuli, such as light, heat, and electricity, and exhibit excellent stability. Furthermore, by leveraging the differential bending performance of its two sides, a flexible robot capable of crawling under near-infrared light (NIR) irradiation has been developed. This robot demonstrates a relatively fast NIR response time (11.2 s) and recovery time (7.7 s). Furthermore, doping MXene with NiFe 2 O 4 nanoparticles endows the flexible robot with magnetically responsive actuation. Under multi-stimuli control, the composite actuator can crawl through complex paths. Additionally, actuators with such characteristics can be applied to asymmetrically structured flexible grippers. Under a light intensity of 180 mW/cm 2 , the gripper achieves a bending angle of 182°. This work provides an effective strategy for the design and fabrication of flexible actuators and bioinspired intelligent devices.