Smartwatches have slowly become a must-have wearable for many techies. However, the tiny screens on these gadgets can be frustrating to use for some, with operations even as basic as swiping through notifications proving difficult to do. To solve this annoyance, a team of designers at Carnegie Mellon’s Human Computer Interaction Group have come up with the ingenious solution of extending the watch’s interface beyond the screen. The technology, called SkinTrack, turns the arm into an extended “touchscreen” for the gadget.
The demonstration video for the product shows the user’s skin swiped and pressed with a finger and used like a touchscreen. The screen cursor reacts accordingly with little lag as the finger navigates across the user’s arm.
A smoother, more responsive version, which uses a camera to track finger motion, has already been developed. It tracks user input continuously, says Gierad Laput, who co-wrote the paper describing SkinTrack, which requires a Kinect, a motion-tracking camera for the Xbox game console, to placed on a user’s shoulder. For the SkinTrack, Carnegie Mellon researchers did away with the camera and instead developed a ring that emits a high-frequency signal into the user’s tapping finger, which is then propagated back into the electrode-embedded wristband upon touch.
SkinTrack determines the position of a user’s tap by measuring the frequency of the oscillating signal’s arrival at the electrodes. Such measurement, called phase difference, gives the technology its accuracy. One glaring limitation of the system, however, is its lack of UI projection, which means a user has to guess where to initially tap their fingers. While it does not affect in the overall accuracy of the input, it would still be more convenient to see an actual interface where a touch would fall. Laput believes such a system would need years to complete.
Another problem that will hold the product back from being available to consumers at the moment is the issue of system calibration, which must be done individually as each person’s body conducts electricity uniquely. Even if such limitations exist, the technology to utilize a part of the body as an extension of the touchscreen is already here and that in and of itself is already an impressive achievement for the group.
“Looking at the bigger picture, you can make your arm into an actual sensor,” said Laput. “If you imbue your arm with computation, you’re basically augmenting the human experience.”