Magnetic Robot With Bistable Compliant Mechanism for Snap-Though Jumping and Grasping

Abstract

Jumping locomotion offers a promising means of overcoming obstacles and adapting to unstructured environments. However, enabling millimeter-scale robots to integrate jumping capabilities with multifunctional tasks, such as object grasping, presents significant challenges. This letter presents a millimeter-scale magnetic robot based on a bistable structure, which employs snap-through buckling to achieve high-performance jumping motion and demonstrates effective object grasping. To investigate its bistable behavior, an energy-based theoretical model and a dynamic model were developed and validated through finite element simulations and experiment. The robot exhibits remarkable locomotion performance, achieving a vertical jumping height of 135 mm (45 times its body height), a horizontal distance of 70 mm (15 times its body length), and a rapid takeoff velocity of 1.5 m/s. In addition, the robot is capable of transporting an effective payload exceeding half of its own body weight. Finally, the robot overcame vertical obstacles before grasping and delivering objects, demonstrating its application potential in the transportation of cargoes in complex terrains. The proposed bistable design, combined with magnetic actuation, offers a novel strategy for advancing next-generation autonomous soft robots, enhancing their adaptability and multifunctionality in unstructured environments.