Multi-touch input sensor using an Arduino Mega via Arduino blog. lynxz3 writes -

So i’ve been working on this project for a while now as part of my thesis and independently and work is still continuing. So just an overview the project is a multi-touch and multi-modal input sensor that can be utilised behind traditional LCD panels utilising a new method to detect inputs. By using a large IR sensor array consisting of 128 sensors behind the LCD panel and IR light source in front of the Panel we are able to augment the display with the ability to sense a variety of objects near or on the surface; including fingers tips and hands and thus permitting us to enable multi-touch interaction. The inherent nature of the senors allows us to create a low cost high fidelity image sensor allowing us to take advantage of optical sensing which also allows other physical items to be detected, and thus permits us to develop multi-modal interaction schemas. The Videos below are of a prototype hardware unit that i created. utilising Rev 17 of the sensor board that i developed and created.