Turning surfaces into touch panels: Agranite-touchpad

Abstract

Touch sensing interfaces are used in many human to machine applications with the natural feeling to the touch missing. We propose the use of humantenna touch technique to turn surfaces of natural or artificial conductive or semi-conductive materials into passive touch pads. Because of the conductivity of the human body, AC power lines induce a voltage on the human body which is used as the touch trigger. By the use of electrodes mounted at the edges of the surface, the ratio of voltage detected is used to compute the touch location. Granite touch pad was implemented as an example, and the voltage detected at the electrodes due to various touch locations is presented.