Skin is complicated. It's our body's largest organ, one that ostensibly senses touch — but also temperature, pain, wetness, itching, and more. A new, stretchy artificial skin can pick up many of the sensations from the real thing, and it could someday cover a life-like prosthetic hand.
The skin, developed by researchers in South Korea, combines the ability to sense pressure, temperature, and humidity. Its creators tested it in a number of situations, including typing, holding hot and cold cups, shaking hands, and, yes, even distinguishing between a wet and dry nappy. That accounts for this slightly disturbing image in the Nature Communications paper.
The bulk of the new skin is composed of a flexible, transparent silicone material called polydimethylsiloxane — or PDMS. Embedded within it are silicon nanoribbons that generate electricity when they're squished or stretched, providing a source of tactile feedback. They can also sense whether an object is hot or cold.
The humidity sensors are made up of capacitors. When the polymer surrounding a capacitor absorbs water, the moisture changes the polymer's ability to store a charge. The capacitors measure that storage change and use it to determine the moisture levels of the environment.
Before the artificial skin can be used in prosthetics, though, scientists will have to figure out how to hook it up to a human brain. They have created prosthetic hands that connect to the brain, automatically uploading the texture they sense. Our other sensations could very likely come next. [Popular Science, Nature Communications]
Images: Kim et al/Nature Communications