Wafer-thin, self-adhesive and packed with electronic – that’s what the medical wearables of the future will look like. A new “electronic skin” that constantly measures and transmits a range of vital data comes close to realizing this vision.
Whether worn in the ear, on the wrist or in a shirt, fitness enthusiasts and athletes swear by wearables. But the medical sector has also discovered the benefits of mobile vital data collectors. After all, they should help cushion the devastating impact of rapidly increasing civilization diseases and the demographic shift on our healthcare systems. These devices, however, still record physiological parameters inadequately because they are too big and not close enough to the skin, restrict freedom of movement or cannot be permanently attached all over the body. The materials used to date, such as plastic or rubber, also irritate the skin when worn for longer periods.
Scientists from Northwestern University (NU) and the South Korean Daegu Gyeongbuk Institute for Science and Technology (DGIST) have now developed an “electronic skin” in the form of a plaster for monitoring health data which is self-adhesive, extremely flexible and can be attached to virtually any part of the body. Among other things, it measures the wearer’s heartbeat, breathing, body temperature and, for the first time anywhere in the world, electrical muscle activity (electromyography, EMG). The results are then transferred to a smartphone, for example, via an “air interface”. And the power supply for the sensor plaster is also wireless.
Sensor plasters as “mini labs”
A mere 3.8 cm in diameter, the nanofiber silicon substrate is permeable to oxygen and sweat and packed with 50 electronic components. These are connected by 250 tiny, highly flexible “cable springs” made of gold, chromium and phosphate.
In the future, sensor plasters will also support interactive telemedicine to ensure, for example, that medical care is available to patients with no direct access to a doctor or hospital. And with support from big data and AI technologies, the biosensors could serve as the basis for a whole new holistic healthcare system. The researchers’ to-do list also includes the direct chemical analysis of sweat in order to make diagnoses using biomarkers and administer drugs through the skin.
As John Rogers from Northwestern University, the “father of skin electronics” does, however, also point out that after ten years of research in this field, it’s less about engineering than about optimization and security aspects. After all, the sensor plasters transmit large amounts of highly sensitive data wirelessly.