University of Washington (UW) engineers have developed a new way to bring internet connectivity to low-power electronic devices such as brain implants and smart contact lenses. The interscatter communication system, which creates Wi-Fi transmissions from reflected Bluetooth signals using a fraction of the power normally required, has the potential to impact everything from blood sugar monitoring to splitting credit card bills.

Interscatter enables low-power devices to communicate by using technology already existing in common mobile devices, such as Bluetooth, Wi-Fi or ZigBee radios, to act as the transmitters and receivers for the reflected signals. And, according to the researchers, it is able to create these Wi-Fi signals whilst consuming 10,000 times less energy to do so than standard methods.

Instead of generating Wi-Fi signals on your own, the technology claims to create Wi-Fi using by Bluetooth transmissions from nearby mobile devices such as smartwatches. The system relies on a communication technique known as radio wave backscatter (a diffuse reflection of radio waves back in the direction from which they originated), to enable devices to interchange data by manipulating and reflecting existing signals.

The small sizes and often difficult locations of implanted electronics in the human body often means that power supplies are limited, which puts conventional wireless communication out of play. As a result, medical devices such as smart contact lenses have been unable to send data using Wi-Fi to smartphones without bulky, clumsy external power supplies. These same limitations also restrict other nascent technologies such as brain implants that reanimate limbs or monitor internal organs.

The Interscatter technology can enable Wi-Fi for these implanted devices while consuming only tens of microwatts of power. Building on previous work in this area, the researchers in UW's Networks and Mobile Systems Lab and Sensor Systems Lab designed and created prototype devices that specifically target previously impractical applications, building interscatter communications systems for a smart contact lens and an implantable neural recording instrument which can directly communicate with smartphones and smartwatches.