Get the skinny on SkinTrack!

A new development at Carnegie Mellon University will mean big things for the smallest of screens.

Students at the Future Interfaces Group (FIG), an interdisciplinary research lab within the Human-Computer Interaction Institute (HCII), have created SkinTrack, a system that expands the area of smartwatch interaction beyond the watch face. The technology turns the user’s forearm into a touchscreen, allowing control of the device with just a tap or swipe of a finger against the skin’s surface.

“We’re looking at how smartwatches are being used, and right now users are confined to very limited interactions,” says Gierad Laput, an HCII PhD student behind the project. “There was an opportunity for us to look at the watch and figure out how we can use the area around the device to make the smartwatch bigger in terms of interaction, without actually making it physically bigger.”

The system does involve one fashionable catch. SkinTrack requires the user to wear a ring that emits a low-energy, high-frequency signal. When the high-tech accessory gets close to or touches the skin near the smartwatch, the signal is picked up and tracked by electrodes built into the device’s band.

While SkinTrack isn’t the first so-called “skin to screen” technology to emerge, the FIG researchers see it as a more practical option.

“We saw some previous work figuring out how to get touch sensing on the skin,” says Yang Zhang, a first-year HCII PhD student who also worked on the project. “But their setup involved a camera worn on the shoulder or an overlay on top of the skin. It’s a little more obtrusive.”

Research showed that SkinTrack was accurate enough to use as a game controller, scroll through lists, zoom in and out of onscreen maps, or even draw. The system also includes an application that enables users to use the back of the hand as a dial pad to enter numbers and make phone calls.

The FIG researchers still have some hurdles to overcome, including decreasing the size of the ring’s large battery. There’s also the inevitable challenge of addressing concerns regarding the electrical signals produced by the system.

“We are constantly bombarded by electrical signals,” says Laput, using fluorescent lights and power outlets as examples. “You don’t know, because you don’t see it. These are very low current, low power signals. It doesn’t really affect the human body.”

Zhang, who has acted as test subject by wearing SkinTrack 24 hours a day for weeks, concurs that the technology is perfectly safe. Says Zhang, “If there were any side effects, I should have known about them at this point.”

SkinTrack will make its public debut when Zhang presents details on the project at ACM CHI 2016, the Association for Computing Machinery’s Conference on Human Factors in Computing, in San Jose, CA.

Watch the video below to see how SkinTrack works: