20 January 2021
E-skin shows promise for prosthetics
Published online 3 December 2020
A robust electronic skin can sense and monitor blood pressure, finger movements, and an approaching object.
A sensitive and robust electronic skin shows promise for developing the next generation of prosthetics, soft robotics, human-machine interfaces and personalized healthcare systems.
The hydrogel-based e-skin sensor can withstand repeated peeling and scratching, and heals automatically following a punch, says materials scientist, Vincent Tung, from King Abdullah University of Science and Technology, Saudi Arabia, who developed the e-skin in a team with colleagues at KAUST, and in the US, and China.
The team developed a prototype by depositing metallic nanosheets on conducting nanowires. These were attached to a nanoparticle-incorporated polymer hydrogel.
The e-skin can sense the tiny vibrations caused by blood pressure changes in arteries, in addition to finger, limb and joint movements. It also senses temperature and touch in real time, in addition to sensing objects coming to it from 20 centimetres away. These contact and non-contact sensing modes could be useful in prosthetics and robotics. The sensor also distinguishes individual letters written on the skin, suggesting its potential as a pressure sensor.
The scientists say it is more sensitive and durable than existing e-skins which, when stretched, easily crack and their circuits break. With a response time of less than a second, it works even after being subjected to 5,000 test cycles of deformation.
Data captured by the e-skin sensors can be wirelessly transmitted, stored and then translated into distinguishable signals. Tung says the team next aims to convert the e-skin data into readable texts.
Cai, Y. et al. Mixed-dimensional MXene-hydrogel heterostructures for electronic skin sensors with ultrabroad working range. Sci. Adv. 6, eabb5367 (2020).