Design, Fabrication, and Characterisation of a Novel Piezoimpedal Tactile Sensor for use in Soft-Prosthetic Devices

Enabling the robotic ability to sense tactile interactions is a complex and interdisciplinary challenge, as traditional pressure sensors made of hard and rigid materials struggle to replicate the soft and compliant interactions of mammalian somatosensory networks. This study investigates a novel matrixed contact sensor designed for use in soft robotics and biomedical prosthesis applications. The sensor is a coupled piezocapacitive-piezoresistive tactile sensor, optimized for scalability over various mechanical stimuli, including touch, pressure, bend, stretch, and proximity. By modifying the bulk geometry to include dielectric artifacts and integrating electroactive elastomeric composites, the soft and flexible sensor is fully mechanically compliant and conforms to skin behavior. The sensor has a maximum sensitivity of 0.028kPa-1, a resolution of 1.3%, and a bandwidth of 29Hz. The study characterizes the sensor's performance and identifies its static and dynamic response to aid in developing complex, closed-loop tactile feedback control systems toward realizing the biomimetic implementation of synthetic skin in soft-prosthetic devices.