Motion UI: Motion-based user interface for movable wrist-worn devices

Today's consumer wearable devices such as smart-watches and fitness trackers suffer from limited usability owing to a diminutive touchscreen integrated into the device. In this paper, we propose a motion-based user interface that uses built-in 6-axis sensors to express and identify four directional taps on the body of a movable wrist-worn device. We first present a concept and design of this user interface, followed by an implementation on a commercial smartwatch to demonstrate an enabling user interaction applied to consumer wearable devices.