Skin buttons

Smartwatches are a promising new interactive platform, but their small size makes even basic actions cumbersome. Hence, there is a great need for approaches that expand the interactive envelope around smartwatches, allowing human input to escape the small physical confines of the device. We propose using tiny projectors integrated into the smartwatch to render icons on the user's skin. These icons can be made touch sensitive, significantly expanding the interactive region without increasing device size. Through a series of experiments, we show that these 'skin buttons' can have high touch accuracy and recognizability, while being low cost and power-efficient.