Magnetic arthropod soft robot with triboelectric bionic antennae for obstacle identifying and avoidance

Magnetic soft robots exhibit attractive advantages such as nontethered constraints and remote control capabilities, with broad prospects in environmental exploration, minimally invasive surgery and other fields. However, constrained by the magnetic control mode and the high flexibility of the soft materials, achieving rapid movement and perception-feedback of magnetic soft robots are still challenging. Therefore, this paper aims to draw inspiration from biomimetic joint structures to design and fabricate a magnetic arthropod soft robot capable of rapid cyclic extension-contraction deformation under an alternating magnetic field. First, a type A magnetic arthropod soft robot (MASR-A) is developed with a speed up to 1.4 body length per second (BL/s) with three-joint-unit. Next, we designed a type B magnetic arthropod soft robot (MASR-B) that offers higher flexibility and deformation adaptability with bodies owing five-joints structure. Then, inspired by snail's tentacles, we developed bionic antennae based on triboelectric tactile sensors (TTSs), which can convert external mechanical collisions into electrical signals output, with a sensitivity of up to 0.13 V KPa−1. By mounting the bionic antennae on the head of MASR-B to realize the magnetic soft robot's sensing function, enabling MASR-B to detect collisions with obstacles of various materials (PMMA, Resin, PLA and etc.). Particularly, the bionic antennae consists of two completely independent triboelectric sensing units (LTTS and RTTS). The signals from these two TTSs are received and identified by a microcontroller to determine the direction of obstacle relative to the robot. The relay is then controlled to alter the magnetic field generated by the electromagnetic coils to enable MASR-B to avoid obstacle. This paper provides a biomimetic design approach for the rapid movement and flexible sensing of magnetic soft robots.