Integrated actuation and sensing abilities for soft pneumatic composite structures

Soft pneumatic structures are promising for the actuation of soft machines, and substantial advances have occurred in their innovative design and functional verification. However, most pneumatic structures lack self-sensing abilities, resulting in a lack of motion state feedback and difficulty in achieving real-time closed-loop control. Herein, a soft pneumatic composite structure (SPCS) with integrated actuation and sensing abilities is developed by combining a bellows-shaped magnetic elastomer and a wire structure. The SPCS can generate an induced voltage under deformation. The SPCS mechanical and magnetoelectric characteristics are studied comprehensively. The SPCS experimental maximum contraction is 27 mm, which is close to the theoretical and numerical results. When the SPCS is actuated by a pressure of −40 kPa, it will generate a peak induced voltage of 1.01 mV. With the increase in magnetic powder content and turns of the spiral wire, the induced voltage also increases. Additionally, two SPCSs are used to develop a self-sensing actuator, which can accurately perceive the bending direction and recognize the magnitude and direction of external force. A self-sensing soft gripper is developed, which can sense the grasping status and predict the width of grasped objects. Furthermore, a smart vehicle detection system composed of two SPCSs is proposed, which can detect the number, speed, and weight of passing vehicles. Consequently, the SPCS has numerous potential applications in soft sensors and self-sensing intelligent soft machines.