“Smart” prosthetic skin made from silicon nanoribbons is reported this week in Nature Communications. This smart skin includes strain, pressure, and temperature sensor arrays as well as humidity sensors, heaters, and stretchable multi-electrode arrays for nerve stimulation.
Sensory receptors in human skin transmit signals from external environments to the brain. Despite advances in our understanding sensation, replication of these unique characteristics in artificial skin and prosthetics remains challenging. Recent efforts to develop smart prosthetics, which use rigid or semi-flexible pressure, strain, and temperature sensors, provide promising routes for sensor-laden bionic systems. However, there is still a mismatch between conventional electronics in wearable prosthetics and soft biological tissues, which impedes the utility and performance of prosthetics in amputee populations.
Dae-Hyeong Kim and colleagues describe a stretchable prosthetic skin equipped with numerous sensor arrays, which are tuned to stretch according to the movement of a target skin segment. The authors state that the design can dramatically enhance the perception capabilities of artificial skin in response to changing external environments. Integration of stretchable humidity sensors and heating elements further enables the sensation of skin moisture and body temperature regulation, respectively. Corresponding electrical stimuli can then be transmitted from the prosthetic skin to the body to stimulate peripheral nerves via an ultrathin multi-electrode array, which is decorated with ceria nanoparticles for inflammation control. This design may provide unique opportunities for emerging classes of prostheses and peripheral nervous system interface technologies.