Multiplexed Piezoelectric Electronic Skin with Haptic Feedback for Upper Limb Prosthesis

Abstract

Upper limb amputation severely impairs tactile perception, limiting daily activities. Developing a near-natural replacement with prosthetic devices requires improving user sensory experiences during object interactions. The ideal upper limb prosthesis should provide real-time sensory feedback, mirroring natural experiences. Current prostheses struggle with providing adequate tactile feedback due to sensory limitations. Inspired by the sensory properties of skin, we present a micro-fabricated, multiplexed electronic skin (e-skin) with actuators for sensory feedback in upper limb amputation. The piezoelectric-capacitive sensor array detects static pressure, temperature, vibration, and texture, with integrated actuators stimulating the skin to provide real-time feedback. The sensors integrate with actuators via readout electronics, making the system standalone and easy to use. The flexible, compact sensor array design (two pixels within a 1 cm² footprint) detects a wide range of pressure (0.5–10 kPa), temperature (22–60 °C), vibration (35–100 Hz), and texture (2.5–45 Hz), suitable for daily use. The e-skin, attached to a prosthetic finger, is tested for feasibility on human volunteers with wrist-mounted actuators. Statistics are used to quantitatively assess system performance. The integration of multiplexed sensors and actuators enhances tactile feedback, improving the quality of life for people with upper limb amputations.