Soft Robotic Proprioceptive Posture and Positioning Enhancement via Distributed Multifield Magnetic Inductive Sensing

Soft robots’ highly flexible and adaptive movements drive demand for sensing methods to control their posture and position. Recently, magnetic sensing has shown promising perspectives in advancing soft robotic applications, offering high design adaptability and exceptional sensing performance by eliminating the need for soft-material substrates. In this article, we further explore the utilization of magnetic inductive sensing mechanisms with multiple magnetic fields in soft pneumatic robots to track distributed key points, enabling flexible and versatile configurations of soft robotic modules over a large sensing range. We introduce a soft robotic distributed multifield magnetic inductive sensing approach that configures magnetic coils at key distributed points within the soft robotic bodies to obtain proprioceptive posture information and extend the sensing range by overlapping multiple magnetic fields. It facilitates a modular design capable of assembling and disassembling different soft robotic modules without compromising the overall system or requiring a redesign, expanding the sensing functionality from proprioceptive posture to mutual positioning, and demonstrating the modularity and scalability of the system. The methodology, from concept, modeling, design, fabrication, to validation, enables motion feedback control in pneumatic soft robotic systems. We demonstrate the potential for expanded applications in a soft two-segmented robot, a soft finger-assembled arm, and a two-crawling robot system, showcasing its high flexibility in modular design, as well as high sensing performance in large ranges for robotic motion control.