SkinTrack Turns the Arm into a Touchscreen

The SkinTrack invention expands a smartphone’s display by turning the wearer’s arm into a touchscreen. As the ring sends electrical signals through the skin, the band’s electrodes detect the varying signals to track distance and movement, effectively expanding the display screen onto the skin.

http://www.wired.com/2016/05/device-turns-arm-touchpad-heres-works/