Highly Bendable Ionic Soft Actuator Based on Nitrogen-Enriched 3D Hetero-Nanostructure Electrode

Abstract

Electrically responsive ionic soft actuators that can exhibit large bending strain under low electrical input power are promising candidates for future soft electronics and wearable devices. However, some drawbacks such as low blocking force, slow response time, and poor durability should be overcome for practical engineering applications. Herein, this study reports defect-engineered 3D graphitic carbon nitride (GCN) and nitrogen-doped graphene (NG) hetero-nanostructure that were developed by one-pot hydrothermal method in order to design functionally antagonistic hybrid electrodes for superior ionic soft actuators. While NG facilitates rapid electron transfer in 3D networked nanoarchitectures, the enriched-nitrogen content in GCN provides good wettability and mechanical resiliency with poly(3,4 ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The 3D hybrid nanostructures generate unimpeded ion channels and sufficient contact area with the electrolyte membrane to provide higher capacitance and mechanical integrity, which are critical prerequisites for high-performance actuation. The developed soft actuator based on the nitrogen-enriched 3D hetero-nanostructure is found to exhibit large bending strain (0.52%), wide frequency response, 5 h durability (93% retention), 2.4 times higher bending displacement, and twofold higher electromechanical efficiency compared to PEDOT:PSS under +/- 0.5 V input voltage. Such 3D functionally antagonistic hybrid electrodes offer hitherto unavailable opportunities in developing ultralow voltage-driven ionic actuators for the next-generation soft electronics.