Touch-sensing artificial skin works much like the real thing
Medicine, soft robotics and wearable electronics are just a few of the fields that could benefit from a new hydrogel that's applied to the body. The transparent material can sense when it's being touched, bent, heated, or otherwise manipulated.
Developed by a team at the University of Toronto, the hydrogel is in fact made of two oppositely-charged sheets of gel that are stacked one on top of the other.
When the material is subjected to mechanical strain, humidity, or changes in temperature within one area, positively- and negatively-charged ions move across the junction between the two sheets. This movement, which occurs at what is called a "sensing junction" on the hydrogel's surface, can be measured as an electrical signal.
The inexpensive material is also very adhesive, highly stretchable and biocompatible, so it can easily be stuck to the skin without breaking or prematurely peeling off. It has therefore been named "artificial ionic skin," or AISkin for short.
Once developed further, it could be incorporated into items such as gloves that measure the extent of finger movement in hand-rehab patients, wearable touchpads for use by gamers, or fingers that give a sense of touch to soft robotic grippers handling delicate objects.
The scientists also hope to add bio-sensing capabilities to the AISkin, so bandages or sportswear made from it could measure biomarkers in users' sweat or other body fluids.
"If you look at human skin, how we sense heat or pressure, our neural cells transmit information through ions – it’s really not so different from our artificial skin," says the lead scientist, Professor Xinyu Liu.
The research is described in a paper that was published this week in the journal Materials Horizons.
Source: University of Toronto