Thanks to Wi-Fi and Bluetooth, the modern world is awash in 2.4-GHz radiation. A semiconductor startup in Israel, Wiliot, thinks it can use some of that RF energy to free the Internet-of-Things from batteries and other energy storage devices.
“There’s a lot of Bluetooth energy,” says Steve Statler, senior vice president of marketing and business development at Wiliot. “You’re bathed in it.” Add up ordinary Bluetooth traffic, Wi-Fi signals, and those from Bluetooth 5.0, the newest iteration which can blast signals a kilometer or more, and there’s enough energy that simple beacon tags won’t need any form of energy storage, the company believes.
Wiliot’s goal is to begin selling fingernail-size devices in 2019 that are as thin as a sheet of paper and cost less than $1. Such a device, it says, would be able to receive and transmit Bluetooth messages and do some limited computing using only ambient RF energy. Critically, it will do this without storing energy in a battery or supercapacitor, which Statler says would make devices too bulky. Wiliot expects its slimmed-down version to be used for smart packaging, indoor location services, clothing tags, asset tracking in warehouses, TV remote controls, and other purposes.
The device rests on two main technologies. The first is a form of processing the company calls wave computing. Statler describes it as way to intelligently prioritize what computing and data storage should be done when there’s available RF energy.
The second technology is called backscattering. It basically remodulates a Bluetooth signal coming in one channel. Then, it uses a small amount of power harnessed from that original signal to send the modulated signal out on another channel. Engineers at the University of Washington have demonstrated backscatter on cellular signals, Wi-Fi, Bluetooth, and LoRa signals, with which it could transmit over a distance of several kilometers.
Qualcomm and the German chemical and pharmaceutical firm Merck KGaA are Wiliot’s most recent investors, bringing the startup’s venture capital infusion to $19 million since its founding in January 2017.
Wiliot is hardly alone in the push to drive down the size and power consumption of IoT computers. (University of Michigan spinoff Cubeworks, for example, has been developing nanowatt-class millimeter-scale IoT computers called micromotes.) But the nod from Qualcomm seems proof that the startup has potential.
“As we look at the IoT space, we see battery-free Bluetooth technology as the next great leap, driving exponential growth for the entire IoT ecosystem, from smartphones and Wi-Fi hubs to battery powered beacons,” Boaz Peer, director of Qualcomm Ventures Israel, said in a press release.
Samuel K. Moore is the senior editor at IEEE Spectrum in charge of semiconductors coverage. An IEEE member, he has a bachelor's degree in biomedical engineering from Brown University and a master's degree in journalism from New York University.