Smartwatch prototype uses laser projection to turn your arm into a touchscreen

As they stop being smartphone accessories and increasingly stand apart as full-fledged devices in their own right, we totally dig smartwatches. But they do have one big (or, should we say, small) problem it’s difficult to get around: Their diminutive screen size reduces the surface area users can interact with. Since touch gestures remain the best way of interacting with mobile devices, that poses a bit of a challenge.

Fortunately, terms like “big problem” and “a bit of a challenge” are exactly what get the folks at Carnegie Mellon’s Future Interfaces Group (FIG) out of bed in the morning. To help deal with this particular conundrum, they’ve developed a prototype for a special smartwatch that vastly increases its capacitive touch surface area by projecting a touchscreen onto a user’s arm. The work was carried out in association with China-based tech company ASU Tech.

This is achieved using a 15-lumen scanned-laser projector that’s bright enough that it can be viewed both inside and outside. A depth-sensing array is then used to register the different touch gestures — while the team has even thought to consider a “slide to unlock” mechanism to avoid false positive gestures being recognized when, say, you simply scratch your arm. In all, the self-contained LumiWatch creates an interactive surface area of 40cm squared, more than five times that of a typical smartwatch display.

“It’s an entire computer, with battery that lasts a day, plus a projector for on-skin graphics, as well as a custom depth sensor that allows us to track touch input on the skin,” Chris Harrison, head of FIG, told Digital Trends.

Harrison suggested that the LumiWatch could potentially be the kind of innovation that takes smartwatches in general to the next level. “The computational difference between a smartphone and smartwatch is very small,” he continued. “The big difference is the screen. Smartwatches have yet to gain traction in large part because the interfaces are so meager you can’t do much with them. If we can solve that problem – give smartwatches big screens – we might be able to make them first class devices.”

So will we ever get to see this in action? Quite possibly. “We collaborated on this proof-of-concept hardware with ASU Tech, a consumer electronics OEM in China,” Harrison said. “They are well positioned to take this to the market. Beyond that, I can’t say much more.”

In other words, watch this space. And, if you’re reading this on a smartwatch, be aware that you may soon be able to do said space-watching on a much larger (and slightly hairier) canvas!