Electronics system integration and characterization of electronic skin for prosthetic applications

Upper limb amputation significantly disrupts tactile perception, having a crucial impact on daily activities. For attaining a prosthetic device that closely mimics natural functioning, it is crucial to provide users with enhanced sensory experiences during interactions with objects. Through sensory feedback, the ideal upper limb prosthesis must provide real-time mirroring of the user's natural experiences. Current prostheses face challenges in delivering substantial tactile feedback due to their limited sensory capabilities. Here, inspired by the sensory characteristics of the skin, we describe a micro-fabricated and multiplexed electronic skin that is combined with a suite of actuators for sensory feedback capabilities, and employed for upper limb amputation. The set of piezoelectric-capacitive sensors can identify static pressure, temperature, vibration, and texture, while the incorporated actuators offer instantaneous feedback through skin stimulation. The fabricated sensor array has a flexible structure and a compact design of two pixels inside a 1 cm2 footprint. This array of sensors is capable of detecting a wide range of pressure (0.5-10 kPa), temperature (22-60 °C), vibration (35-100 Hz), and texture (2.5-45 Hz) which are the most important tactile sensations of the human skin. The electronic skin is affixed to a prosthetic finger, while the actuators are positioned on the wrists of the human volunteers. Human participants participated in feasibility tests of the system, and its performance was quantitatively evaluated using statistical methods. The incorporation of multiplexed sensors and actuators introduces novel prospects for delivering improved tactile feedback and enhancing the quality of life for individuals with upper limb amputation.