Ex-Space: Expanded Space Key by Sliding Thumb on Home Position

We describe a method termed Ex-Space to enable continuous, one-dimensional keyboard input on the home position. The method features thumb movement on the space key. We developed a prototype of the method consisting of a piece of conductive fabric attached to the space key to detect the position of the sliding thumb. In addition, we performed two preliminary experiments: an experiment to calculate the resolution afforded by touch position detection, and an experiment to explore the performance of menu command input using Ex-Space.