Over the last few years, we have seen quite a few flexible electronic circuits that can be worn on the skin, offering a taste of a next generation of wearable fitness trackers that could simply be slapped on like a temporary tattoo. The latest such device to cross our desk promises greater flexibility and a more compact form than earlier solutions, by making use of an innovative spider web-patterned coil system that enables it to be bent in any direction.
The new electronic skin was developed by scientists at South Korea's Daegu Gyeongbuk Institute of Science and Technology (DGIST), and Northwestern University. Part of its pliability comes from a blob of protective silicone about four cm (1.5 in) in diameter, which houses the circuits and conforms the device to the body.
The other part comes from the way the circuits themselves are arranged. Around 50 different components are connected to one another by 250 tiny wire coils, which are given a unique characteristic through a neat little trick.
The scientists first stretched out the elastic silicone base, while wire arcs made from gold, chromium and phosphate were laid flat on top and the ends of each arc were firmly pinned down onto the base. As the base contracts, the arcs pop up to form three-dimensional coils, which allows them to stretch and contract like a spring without breaking.
They are configured in what is described as an unusual spider web pattern, which is designed to enable the extreme levels of stretchability and flexibility in any direction. This arrangement also allows the coils to be packed into a tighter space, which helps keep the device compact.
When worn on the skin, the researchers say the device can track heart rate, respiration and muscle movement, along with other health data like electrical activity in the heart and muscles. From there, it transmits the health data wirelessly to a smartphone application.
"Combining big data and artificial intelligence technologies, the wireless biosensors can be developed into an entire medical system which allows portable access to collection, storage, and analysis of health signals and information," says Kyung-In Jang, a professor of robotics at DGIST. "We will continue further studies to develop electronic skins which can support interactive telemedicine and treatment systems for patients in blind areas for medical services such as rural houses in mountain village."
The team has published its research in the journal Nature Communications.