Our skin is our largest organ. And it’s amazingly sensitive, capable of feeling everything from the burn of a hot stove to the caress of a lover.
But reproducing those sensations in a machine isn’t easy. It requires mimicking the skin’s sophisticated geometery and function.
Despite these obstacles, scientists have just come a big step closer. A team of researchers has made electronic skin that’s capable of detecting moving touch, temperature, and vibration, they reported Friday in the journal Science Advances.
These “e-skins” could one day endow robots with a humanlike sense of touch, and could also lead to better prosthetics and wearable health sensors, the researchers say.
Scientists have previously developed flexible electronic skins that mimicked human touch. In 2005, researchers at the University of Tokyo created large, flexible networks of temperature and pressure sensors based on an organic semiconductor.
More recently, scientists at Stanford University made artificial skin out of carbon nanotubes and hooked it up to the brains of mice, presumably giving them a faux sense of touch.
But these artificial skins were limited: They could only sense temperature or discriminate between touches on the skin that weren’t moving.
Chemical engineer Jonghwa Park of the Ulsan National Institute of Science and Technology in South Korea and his colleagues wanted to create something that could sense dynamic touch — like, say, someone dragging a finger along your arm.
In human fingerprints, tiny ridge patterns amplify the touch signals detected as you move your finger across a surface. And tiny, interlocking structures sandwiched between the outermost layer of skin (the epidermis) and the middle layer (the dermis) transfer feelings on the skin to mechanical sensors beneath the surface.
Inspired by this, Park and his team etched fingerprint-like patterns into magnetic films. This e-skin was capable of detecting static touch and temperature at the same time.
The researchers also demonstrated their e-skin’s ability to take someone’s heartrate and blood pressure — which can reveal problems like heart disease or high blood pressure — as well as its ability to measure skin temperature.
Because it can separate the temperature from the blood pressure, the researchers said, the e-skin may even provide more accurate readings than traditional medical devices. It’s also capable of detecting dynamic touch and vibrations as well as different textures, including sandpaper, glass, and paper.