Researchers from Northwestern University and the University of Illinois have developed a discreet, wearable device that provides around-the-clock monitoring of both heart and skin health.
The skin-like patch measures a mere five centimeters square and is designed to be worn directly on the skin, for example on a user’s wrist much like a band aid. With comfort in mind, the researchers have made the device extremely thin and flexible so that it is barely felt by users.
“The device is very practical—when your skin is stretched, compressed or twisted, the device stretches, compresses or twists right along with it,” co-first author Yihui Zhang said in a news release.
Northwestern University/University of Illinois via Gizmag
The device works by using temperature changes at the skin’s surface to establish the wearer’s blood flow rate, which is indicative of both cardiovascular health and skin hydration. As described in Nature Communications, this temperature sensing is achieved through 3,600 thermochromic liquid crystals—each one only 0.5 mm squared—that are arranged on a flexible, stretchy substrate. Thermochromic substances are those that change color in response to changes in temperature; your childhood favorite mood rings feature these crystals.
When the patch changes color due to temperature changes, the user is immediately alerted that something is wrong. Imaging sensors and computer algorithms then translate the data into a health report, a process that takes a mere 30 seconds.
Because of the sheer number of tiny, closely packed crystals, the device provides sub-millimeter spatial resolution that is not far off from the infrared technology that is already used in clinical settings. However, this device is significantly cheaper than existing technologies and is also portable, unlike infrared machines that are restricted to hospitals. What’s more, it’s also wireless and can be powered by radio frequency signals in the air. Hopefully with further testing, the device will soon be made available on the market.
“These results provide the first examples of ‘epidermal’ photonic sensors,” corresponding author John Rogers said in a news release. “This technology significantly expands the range of functionality in skin-mounted devices beyond that possible with electronics alone.”