Self-Powered, Soft and Breathable Human–Machine Interface Based on Piezoelectric Sensors

Wearable electronics revolutionize human–machine interfaces (HMIs) for robotic or prosthetic control. Yet, the challenge lies in eliminating conventional rigid and impermeable electronic components, such as batteries, while considering the comfort and usability of HMIs over prolonged periods. Herein, a self-powered, flexible, and breathable HMI is developed based on piezoelectric sensors. This interface is designed to accurately monitor subtle changes in body and muscle movements, facilitating effective communication and control of robotic prosthetic hands for various applications. Utilizing engineered porous structures within the polymeric material, the piezoelectric sensor demonstrates a significantly enhanced sensitivity, flexibility, and permeability, highlighting its outstanding HMI applications. Furthermore, the developed control algorithm enables a single sensor to comprehensively control robotic hands. By successfully translating piezoelectric signals generated from bicep muscle movements into Morse Code, this HMI serves as an efficient communication device. Additionally, the process is demonstrated by illustrating the execution of the daily task of “drinking a cup of water” using the developed HMI to enable the control of a human-interactive robotic prosthetic hand through the detection of bicep muscle movements. Such HMIs pave the way toward self-powered and comfortable biomimetic systems, making a significant contribution to the future evolution of prosthetics.