High-Performance Hierarchical Black-Phosphorous-Based Soft Electrochemical Actuators in Bioinspired Applications.

Bioinspired methods allowing artificial actuators to perform controllably are potentially important for various principles and may offer fundamental insight into chemistry and engineering. To date, the main challenges persist regarding the achievement of large deformation in fast response-time and potential-engineering applications in which electrode materials and structures limit ion diffusion and accumulation processes. Herein, a novel electrochemical actuator is developed that presents both higher electromechanical performances and biomimetic applications based on hierachically structured covalently bridged black phosphorous/carbon nanotubes. The new actuator demonstrates astonishing actuation properties, including low power consumption/strain (0.04 W cm-2 %-1 ), a large peak-to-peak strain (1.67%), a controlled frequency response (0.1-20 Hz), faster strain and stress rates (11.57% s-1 ; 28.48 MPa s-1 ), high power (29.11 kW m-3 ), and energy (8.48 kJ m-3 ) densities, and excellent cycling stability (500 000 cycles). More importantly, bioinspired applications such as artificial-claw, wings-vibrating, bionic-flower, and hand actuators have been realized. The key to high performances stems from hierachically structured materials with an ordered lamellar structure, large redox activity, and electrochemical capacitance (321.4 F g-1 ) for ions with smooth diffusion and flooding accommodation, which will guide substantial progress of next-generation electrochemical actuators.