Design of a Bioinspired Robotic Hand: Magnetic Synapse Sensor Integration for a Robust Remote Tactile Sensing

Integrating tactile sensors into robotic applications is still a challenge because of sensor interconnection and various form factors. Newly developed magnetic synapse sensors have high sensitivity and remote sensing capability, but integration with a robotic finger is an issue because of the air-transmitting tubes that need to be connected from the sensor to the remotely located base unit. This study proposes an integrated design of a multijoint robotic finger with magnetic synapse sensors inspired by the human's joint structure and synapse system. The joint unit inspired by human's finger joints for the usage of the magnetic synapse sensors can easily has hollow channels and insert air-transmitting tubes through a rotating joint compared to the traditional pin joint. The rolling contact joint also minimizes the length variation of the tube when the joint rotates because the center of rotation changes. Modularized sensor units capable of changing the sensor sensitivity and sensing range have been developed and applied to the remote tactile sensing system. A three-finger gripper with three joints per finger with an integrated three-tactile sensor array was prototyped to explore the feasibility of the units. The sensor sensitivity was 0.016 mV/kPa and the sensing range was 350 kPa. The robotic fingers integrated with a high-sensitivity sensor array can grasp objects with various shapes and compliance (i.e., artificial flowers, paper cups, and wine glasses) without damaging the objects using tactile feedback.