Magnetic Bistable Dome Actuators for Soft Robotics with High Volume Capacity and Motion Stability

Magneto-responsive soft actuators hold significant promise in soft robotics due to their rapid responsiveness and untethered operation. However, controlling their deformations presents challenges because of their inherent flexibility and high degrees of freedom. Here, we present a magnetically driven bistable dome-shaped soft actuator that simplifies deformation by limiting it to two distinct states. The actuator achieves controlled state transitions by switching the orientation of external magnetic fields. We investigate the design strategy and magnetization styles of the dome-shaped soft actuator. Additionally, we analyze their effects on state transitions. The bistable dome undergoes significant volume changes reliably and smoothly during deformation, and its natural curvature makes it suitable for tasks involving rolling motion. We demonstrate the actuator's effectiveness in various applications, including an array of bistable domes for controlled actuation, a magnetically driven pulse pump with integrated check valves, and a ball-shaped bistable robot capable of efficient rolling locomotion and fluid manipulation. Our design significantly enhances the versatility and efficiency of bistable soft robotic systems, highlighting their potential for tasks such as liquid collection and release.