Detection of Ungrounded Objects on Mutual Capacitance Touch Screens

Mutual capacitance touch screens are responsible for detecting billions of human fingers touching them around the world every day. Being able to use such screens for detection of ungrounded objects as well, would make it easier develop compatible tangible user interface objects that could extend the functionality of the screens. We present results from both simulations and experiments showing that the sensing principle used in these screens are able to detect ungrounded objects.