Low-cost, low-power Bluetooth wireless technology enables many wearable healthtech devices. In ideal conditions, Low-Energy Bluetooth transmits further than an American football field (>100 meters), but for most health tech applications, a 10 to 20-foot range is more than sufficient. Wireless transmissions demand an energy source, however, and batteries aren’t always the answer. We’ve written about developments in battery-free technology, including a pacemaker powered by microwaves and a fingernail-sized battery-free UV sensor.

Semiconductor developer Wiliot introduced a battery-free Bluetooth sensor tag at a National Retail Federation event in mid- January. Wiliot’s design uses nanowatt computing to communicate with any device using Bluetooth Low Energy. Wiliot glues an ARM microprocessor on an antenna that has been printed on plastic or paper. The device gets sufficient power from scavenged energy from ambient radio frequencies. The sensor tag can communicate proximity, current temperature, product weight, and an encrypted serial number.

While the original use-case for Wiliot’s technology is for tagging garments and other retail products, garment-based health tech wearables and other form factors can also take advantage of the Wiliot design. Applications for memory care units, medication matching, and skin temperature monitoring as well as any situation that involves movement monitoring would be slam dunk candidates for this type of low-cost technology.