A new chameleon-inspired “e-skin” that changes colour the longer and harder you press on it could help engineers design wearables, prosthetics, and robots that are better at sensing pressure and temperature — just like human skin can.
Published last month in the journal Nature Communications, the Stanford University research paper describes the stretchy, colourful polymer. Aside from adding a decorative, customisable coating to smart watches or phones, lead researcher Ho-Hsiu Chou told Phys.org that the e-skin could help us measure pressure applied to a surface, useful for smart prosthetics, exoskeletons, and robots. He says the e-skin could even provide a camouflage function for such devices.
Similar materials have been made in the past, but this stuff is entirely stretchable and better copies organic matter.
The team demonstrated the stuff by giving this teddy bear’s paw, which was outfitted with a pressure-sensitive polymer, a handshake. That polymer was connected to another polymer on the bear’s belly: an electrochromic one that changed colour depending on how much pressure was applied to the bear’s paw. The change in pressure — that is, the strength of the handshake, along with the handshake itself — altered the voltage of the sensor. Those fluctuations altered the chemical makeup of the electrochromic polymer, which caused oxidation that resulted in the colour change.
Why is the colour-changing important? Because it signals to us how much pressure is being applied to a surface. The technology is still experimental, with red and blue as the only two colours. I’m also guessing it will help us control how smart exoskeletons and robots handle, grip, or press objects. And since it’s so stretchy, we could wrap it over curvy or irregular surfaces. Colour me impressed.
Top image via Shutterstock, other images via Nature