Smart contact lenses talk with your phone

Roberto Saracco September 29, 2017 Blog 1,251 Views

This contact lens can be enabled by the WiFi signal generated by your smartphone and use it to power its circuitry to communicate data, like sugar level on the surface of the eye, to the smartphone. Credit: University of Washington

One of the crucial issues in many IoTs is how to power them in ways that they can harvest data and transmit them to a receiver connected to the Internet. Actually the most difficult part is to power the (wireless) transmission because that is where most power is required. Local energy scavenging, like using a temperature gradient between the skin and the surrounding air, may be sufficient to operate the IoT in the harvesting of data (sensing) but it is not enough to support data transmission.

This is particularly important for IoT targeting our body, like patches and smart contact lenses where there is little room for a battery.

At the University of Washington researchers have been working for a while on solving this problem and have come up (watch the clip) in 2016 with an interscatter technology that support data communications using a few µW of power. Now, in a paper presented at the Conference on Mobile Wearable Ubiquitous Technologies they make one step forward showing how to piggy back on radio waves permeating an ambient to establish a radio communications covering up to 2.8km. The technology is called backscattering and basically uses existing radio signals and reflects them in ways that can code a desired signal (watch the second clip). The transmission power used is the one of the existing radio signal and the additional one required to code the signal is close to zero.

This low-cost, flexible epidermal medical-data patch prototype successfully transmitted information at up to 37500 bits per second across a 3,300-square-feet atrium. Credit: Dennis Wise/University of Washington

They have shown how this technology can be applied to establish communications between a smart lens and a cell phone replicating the previous experiment but whilst in the previous one the WiFi signal was used to power the smart lenses and then this one would establish a radio communications, now the incoming signal is used as a bearer signal onto which the data to be transmitted are code and sent through backscattering. The advantage is that the power involved is much smaller and does not generate any appreciable heat, which is good if you are wearing the lens. They have also shown how this technology can enable communications between a smart patch and a receiver.

They expect to have a commercial product available in the first half of 2018.

https://www.youtube.com/watch?time_continue=7&v=MoeFYCGbthk