Wearable Health Tech requires power to work. The size, shape, and type of power can vary, but any form of action requires power. Most wearable devices use batteries, which come with their own challenges of space, weight, and recharging. If you’re going to wear a device on your wrist, on your belt, in a carrying case, or even have it implanted, space for battery power or a port or plug for a wired power attachment figures in the design. Skin patches, sometimes called “temporary tattoos,” designed to monitor biometrics present their own problems; a battery of any significant capacity likely has depth that protrudes and can get caught on clothing. If the battery must be recharged or replaced the required structural elements take up more space.

Researchers based at the University of Illinois at Urbana-Champaign and Hanyang University in Seoul with cooperation from other international institutions have created a stretchable, battery-free skin patch that gets power via near field communication (NFC) in a manner similar to that used for wireless payment systems. A collection of multicolored, light-emitting diodes (LEDs) in a flexible patch can indicate a surprising range of biometric data when activated by a device such as a smartphone or tablet that transmits power wirelessly. The researchers state these “active optoelectronic systems” can monitor heart rate and measure pulse pressure, blood oxygenation, and skin temperature, color,  and UV radiation exposure. These and other potential uses of the patches could make them suitable for frequent measurement checks in both hospital and home care settings. In testing the researchers were able to take readings from 2 centimeters away, but higher powered wireless transmitters could work at greater distances.

Easy to apply, stretchable, flexible, thin, and battery-free patches to track vital signs and skin-related biometrics without wires could make visits to the doctor and hospital stays a lot more comfortable. Just getting rid of all the wires used for ECG/EKGs would be a great help.