Hybrid-excited magneto-responsive soft actuators for grasping and manipulation of objects

Abstract

Magneto-responsive soft actuators have attracted significant attention due to their non-contact nature and exceptional responsiveness. However, existing actuation methods relying on a single magnetic source, such as permanent magnets or electromagnets, suffer from an imbalance between flexible regulation and low energy operation. In this study, we propose a novel hybrid-excited magnetic actuation approach that leverages the synergy between permanent magnets and electromagnets. By utilizing the static magnetic field generated by permanent magnets to stabilize the deformation state of soft actuators, and employing the pulsed magnetic field generated by electromagnets to regulate the deformation, we achieve a harmonious combination of flexibility and energy efficiency. Furthermore, we introduce a two-step magnetization method that enhances the deformability of multi-arm soft actuators, enabling complete closure after deformation. To exemplify the practical implications, we develop a magnetic soft gripper system capable of versatile object manipulation, offering precise control over the grasping and releasing processes without the need for electrical energy consumption. Experimental results demonstrate the exceptional performance of the soft gripper, including a high lifting ratio (larger than 50), fast (<0.05s) and adjustable response. Moreover, we substantiate its potential in real-world scenarios through targeted delivery of single objects with different physical features and simultaneous manipulation of multiple objects with selective capability. This research presents a significant advancement in the field of magneto-responsive soft actuators, offering novel design principles, improved performance, and promising applications across various domains.