A touchscreen may be the perfect input mechanism for a mobile phone, but shrink the screen to smartwatch size and suddenly it seems a lot less elegant. For just that reason, researchers at Carnegie Mellon University have developed a new prototype that relies not on touch, but on physical twisting and tilting for control.
"Smartwatches promise to bring enhanced convenience to common communication, creation and information retrieval tasks," wrote Assistant Professor of Human-Computer Interaction Chris Harrison, who worked on the project. "Due to their prominent placement on the wrist, they must be small and otherwise unobtrusive, which limits the sophistication of interactions we can perform. This problem is particularly acute if the smartwatch relies on a touchscreen for input, as the display is small and our fingers are relatively large."
The solution is a watch that is controlled by a system of mechanical movements -- twists, tilts, clicks and pans -- with a multiple-degree-of-freedom bezel. All these movements can be made using just a finger and thumb.
The team built a series of apps to showcase what the interface can do. For example, a map application can be explored and zoomed by panning and twisting the bezel, and an alarm can be set by twisting. Clicking can be used as a method of selecting -- similar to a mouse click.
The interface is so versatile that it can even be used to control a ported version of first-person shooter Doom. Future versions could incorporate motions such as 3D pan, yaw, pitch and roll -- allowing for even more sophisticated, yet intuitive controls -- and could be implemented in concert with existing input methods, such as touch and voice.
The full paper, "Expanding the Input Expressivity of Smartwatches with Mechanical Pan, Twist, Tilt and Click", can be read online (PDF).