Contact lenses and brain implants that can transmit data may sound like science-fiction gizmos but researchers at the University of Washington are turning them into science fact, thanks to a technological trick they call interscatter communication.
The technology relies on super-low-power devices that can reflect wireless transmissions such as Bluetooth signals, transforming them into data-carrying Wi-Fi signals in the process.
Such devices require mere millionths of a watt to work, and can be shrunk down to the size of a computer chip. The technique is described in a paper to be presented next week at the Association for Computing Machinery’s SIGCOMM 2016 conference in Brazil.
The researchers developed interscatterers shaped like contact lenses and brain implants as test cases.
“Wireless connectivity for implanted devices can transform how we manage chronic diseases,” Vikram Iyer, a UW electrical engineering doctoral student, said today in a news release. “For example, a contact lens could monitor a diabetics blood sugar level in tears and send notifications to the phone when the blood sugar level goes down.”
The technology could also be used to create credit cards and ID cards that exchange data wirelessly, or wearable electronics that can link up with a Wi-Fi network.
“Providing the ability for these everyday objects like credit cards – in addition to implanted devices – to communicate with mobile devices can unleash the power of ubiquitous connectivity,” said Shyam Gollakota, an assistant professor of computer science and engineering at UW.
The key to interscatter technology is that the devices don’t have to generate the power required to send out their own signals. Instead, they merely reflect the signals from an outside wireless source – for example, smartphones, smartwatches, computers or other electronic devices that generate Bluetooth, Wi-Fi or ZigBee radio signals.
The UW team developed a tiny device that takes advantage of backscattering to transform Bluetooth signals into a single-tone signal. That reflected signal could then be modulated to carry a stream of data encoded in accordance with the 802.11b Wi-Fi standard.
Some technical hurdles had to be overcome: The backscattering process tended to create unwanted signals that interfered with Wi-Fi networks. To eliminate those signals, the team came up with a technique called single-sideband backscatter.
Interscatter communication is still a work in progress: The researchers say they’re working on techniques that take advantage of the latest standards for Bluetooth signals as well as upgraded Wi-Fi protocols to speed up data transmission rates.
In addition to Iyer and Gollakota, members of the UW interscatter team include Bryce Kellogg, Vamsi Talla and Joshua Smith. The research was funded by the National Science Foundation and Google Faculty Research Awards.
