Magnetic soft actuators are promising for biomedical and soft robotic applications due to their biocompatibility and magnetic responsiveness. However, conventional designs face a trade-off between achieving high magnetic force and flexibility due to uniform particle distribution. Herein, we propose a novel microscale structure developed by a microscale structure-constrained fluidic formation technique, effectively addressing this limitation and allowing for controlled magnetic powder agglomeration. This approach yields actuators with a low elastic modulus (0.5 MPa) and high magnetic force (12 mN), synergistically combining flexibility and actuation. These performance characteristics significantly advance existing actuators that typically compromise one property for the other. The resulting actuators are readily tailored for complex geometries and programmed to mimic intricate biological movements, such as caterpilla peristalsis, butterfly wing flapping, and grasping. Bionic robots demonstrate potential for inchworm-inspired locomotion, swimming, load-bearing, and quadruped crawling. The enhanced performance and versatility of these actuators pave the way for transformative developments in advanced biomedical devices, soft robotics, and microfluidic technologies.
Zhu et al. (Tue,) studied this question.