Super-Deformed Asymmetric Actuators: Balance of Photothermal and Humidity Response Effects through Structural Regulation

Abstract

It is still challenging to explore intelligent actuators with effective results and achieve a perfect balance between multiple response effects through reasonable structural design and material matching. In order to develop actuators that take advantage of sunlight and humidity resources, asymmetric actuators using sodium alginate (SA) and graphene oxide (GO) as humidity response layers and polyurethane (PU) and poly(dimethylsiloxane) (PDMS) as photothermal response layers were designed. The lamellar GO and SA formed a structure similar to the natural nacre, which improved the humidity response and efficiency of the actuators, as well as the mechanical strength. PDMS was made into 3 μm microspheres that were evenly dispersed in the PU layer, demonstrating its excellent thermal response (maximum bending angle 630°). Based on the above advantages, actuators can be used for bionic simulation of eagle claws, plant tendrils, and lotus, as well as sweat response textiles and smart curtain actuators. This provides insights into multi-response actuators and reveals a wide range of applications.