University of Toronto (U of T) scientists have developed a new human skin-like, super-stretchy, transparent and self-powering sensor.
Dubbed Artificial Ionic Skin (AISkin), the innovative properties of this sensor could lead to future advancements in wearable electronics, personal health care and robotics.
According to U of T Professor Xinyu Liu, since the sensor is basically a hydrogel, it’s inexpensive and biocompatible, and you can put it on the skin without any toxic effects.
“It’s also very adhesive, and it doesn’t fall off, so there are so many avenues for this material,” notes Liu, whose lab is focused on the emerging areas of ionic skin and soft robotics.
According to the scientists, AISkin is made of two oppositely charged sheets of stretchable substances known as hydrogels.
By overlaying negative and positive ions, the researchers have managed to create what they call a ‘sensing junction’ on the gel’s surface.
When the AISkin is subjected to strain, humidity or changes in temperature, it generates controlled ion movements across the sensing junction, which can be measured as electrical signals such as voltage or current.
“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 Liu.
According to Binbin Ying, a visiting PhD candidate from McGill University who’s leading the project in Liu’s lab, AISkin is also uniquely tough and stretchable:
“Our human skin can stretch about 50 per cent, but our AISkin can stretch up to 400 per cent of its length without breaking.”
The new AISkin could open doors to skin-like Fitbits that measure multiple body parameters, or an adhesive touchpad you can stick onto the surface of your hand, adds Liu.
Another application is in soft robotics. An example is soft robotic grippers used in factories to handle delicate objects such as light bulbs or food.
The researchers envision AISkin being integrated onto soft robots to measure data, whether it’s the temperature of food or the pressure necessary to handle brittle objects.
Image and content: Daria Perevezentsev/University of Toronto