Bistable electrostatic soft actuator

Multistable structures are widely utilized to enhance the performance of soft actuators by harnessing the elastic deformation of materials to efficiently store and release potential energy rapidly. They allow actuators to deliver high-speed, powerful motions while maintaining adaptability to dynamically changing environments. In this work, we present a bistable electrostatic soft actuator inspired by the flipping mechanism of hair clips, integrating the benefits of electrostatic actuation with a multistable structure. The actuator utilizes lightweight electro-ribbon actuators to rapidly transition between two symmetric stable states in 0.15 seconds, achieving peak tip velocities of up to 5.0 m/s. The performance of the actuator can be accurately predicted using finite element simulation and effectively customized for specific needs by adjusting the independent actuation and the flipping structure’s parameters. With its combination of lightweight, high speed, efficiency, and design flexibility, the actuator shows great potential for various applications, such as high-speed grippers and jumping robots. It has been particularly demonstrated as a soft propulsion mechanism in liquid.