University of Washington Unveils Breakthrough in Sensor Range and Power Consumption for Wearable Devices

On September 13, researchers at the University of Washington (UW) presented their work on long-range communication for interconnected devices. Their novel long-range backscatter system uses reflected radio waves and provides power and cost efficient long-range communication with sensors that use one thousand times less power than previous technologies. The research team has created prototype contact lenses and epidermal patches that have achieved information transfer across a 3300-square-foot atrium. This is a significant achievement given that most current smart contact lenses have a three foot range. The epidermal patch prototypes can wirelessly collect and transmit useful medical data over similarly large areas with compact and power efficient flexible designs.  

 

Shyam Gollakota, lead faculty and associate professor in the Paul G. Allen School of Computer Science & Engineering presented the team’s research at UbiComp 2017 in Hawaii. On their novel use of reflected radio signals to transmit data at very low power and cost, he said, “Until now, devices that can communicate over long distances have consumed a lot of power. The trade-off in a low-power device that consumes microwatts of power is that its communication range is short. Now we’ve shown that we can offer both, which will be pretty game-changing for a lot of different industries and applications.”

 

The system is comprised of three main components: a radio signal emitter, a sensor to code information, and a low-cost receiver to decode the information. With these, the system has transmitted data up to 1558 feet, or if the sensor is in close proximity to the signal source, as far as 1.73 miles. The device can be powered from extremely thin and flexible batteries, or be adapted to receive power from the environment. This in itself is not new, instead the innovation comes from the team’s creation and implementation of chirp spread spectrum, a new type of radio modulation, which allows the long-range communication through large spaces and physical barriers which traditionally have dampened or greatly inhibited signal range. With this modulation, the team has broken the long-held barrier that prevented interconnected devices of communicating over greater distances with even less power usage. 

 

UW has teamed with Jeeva Wireless, a start-up founded by former UW computer scientists and electrical engineers, to commercialize their long-range backscatter system, with a prospective market date of six months. CTO of Jeeve Wireless, Vamsi Talla, said of their collaboration, “People have been talking about embedding connectivity into everyday objects such as laundry detergent, paper towels and coffee cups for years, but the problem is the cost and power consumption to achieve this. This is the first wireless system that can inject connectivity into any device with very minimal cost.” 

 

The research team projects that sensors made with this process could cost ten to twenty cents each, and could be used in a variety of ways. For example, flexible patches could monitor biometric data or incorporated into other wearable assistive technologies. Alternatively, it could be adapted for home sensing and smart city integration, as well as increasing access to precision agriculture and medical monitoring.