Wi-Fi backscatter eliminates batteries to power and connect IoT devices and sensors

August 06, 2014 // By Jean-Pierre Joosting
There is a lot of hype being generated over the concept of a smartwatch and companies are working hard to on defining this emerging space. However, the holy grail for the IoT is the removal of batteries from devices such as smartwatches and the myriad of sensors that would make up the IoT. Batteries would be replaced by innovative energy harvesting techniques instead.

In this new world order for smart devices, smartwatches or other wearable devices will communicates directly with online profiles, storing information about your daily activities where you can best access it — all without requiring batteries. Battery-free sensors embedded around your home could track minute-by-minute temperature changes and send that information to your thermostat or wearable device to help conserve energy.

This not-so-distant "Internet of Things" reality would extend connectivity to perhaps billions of devices. Sensors could be embedded in everyday objects to help monitor and track everything from the structural safety of bridges to the health of your heart. But having a way to cheaply power and connect these devices to the Internet has kept this from taking off.

Now, University of Washington (UW) engineers have designed a new communication system that uses radio frequency signals as a power source and reuses existing Wi-Fi infrastructure to provide Internet connectivity to these devices. Called Wi-Fi backscatter, this technology is the first that can connect battery-free devices to Wi-Fi infrastructure.

"If Internet of Things devices are going to take off, we must provide connectivity to the potentially billions of battery-free devices that will be embedded in everyday objects," said Shyam Gollakota, a UW assistant professor of computer science and engineering. "We now have the ability to enable Wi-Fi connectivity for devices while consuming orders of magnitude less power than what Wi-Fi typically requires."