Controlling any wearable electronic device is a challenge, and smartwatches are no exception. With their tiny displays, there’s simply not a ton of real estate for a fingertip to operate a touch interface.
In response, Google made virtual buttons big and simple. Apple developed a digital crown to zoom in and out of content. And now, Carnegie Mellon’s Future Interfaces Group has developed a third potential solution called “skin buttons” (PDF), in which they use tiny laser projectors to make controls appear right on your skin.
The sci-fi premise is simple enough to understand. Their prototype contains four micro lasers that are capable of emitting simple icon shapes. They can be anything from a home button for navigation, to play or pause controls for music, to push notifications for email, to rudimentary up and down arrows. At the same time, infrared sensors watch for when your finger taps a button, effectively turning your skin into a touch-screen display.
As you can see in the above video, or read in the accompanying research paper, the prototype works pretty well in terms of pure function. And it’s easy to imagine researchers taking the idea even further, building in buttons of multiple colors, or even full video displays projected on your wrist.
However, such upgrades would almost certainly require more development, bulk, and unit cost. What’s so fun about skin buttons is that the underlying technology could conceivably be squeezed into existing smartwatches for less than $2, today.