Here is a wearable system that allows you to execute wrist gestures on your smartwatch. WristWhirl is designed to handle 8 gestures, including 4 directional marks and 4 free-form shapes. As you can see in this video, users can simply move their wrist to play games, manage their calendar, and interact with their smartwatch without having to use another hand.
The prototype has a 2″ display and 12 infrared proximity sensors, a vibration sensor, and an Arduino Duo. Users can draw common gestures by using their wrist. They can use pinch to indicate the start and end of a gesture.