Moisture-triggered hybrid soft actuator and electric generator for self-sensing wearables and adaptive human-environment interaction

Abstract

As ubiquitous energy available from the human body and surrounding environment, moisture converted into both mechanical and electrical energy simultaneously offers appealing strategies for adaptive self-sensing wearables. However, most energy conversion devices typically achieve only single-form energy conversion. Here, we report an integrated device concept that breaks this limit—a moisture-triggered hybrid soft actuator and electric generator (MTAEG) capable of generating reliable actuation and superior electrical output concurrently. By utilizing printable asymmetric electrodes and hygroscopic polyelectrolyte composite film, we achieve the all-in-one device with hybrid functionalities for effective moisture-energy conversion. The MTAEG demonstrates reversible stable actuation (125° bending angle at 80 % RH) and offers a current density of up to 76.41 μA cm⁻², accompanied by a power density of 11.24 μW cm⁻². This outstanding electrical performance exceeds that of most reported conventional moist-electric generators, thanks to the optimization of asymmetric electroactive electrodes and the excellent ion-transport ability of the polyelectrolyte composites. Moreover, MTAEGs can be compatibly integrated into arrays for various applications, including bioenergy modules, self-powered tracking/sensing, adaptive personal comfort management, and physical activity monitoring. Such printable MTAEGs with ingenious materials combinations, high-throughput fabrication, and attractive performance offer a promising hybrid platform for self-sensing wearables and adaptive human-environment interaction.