Touch surfaces are generally restricted to custom manufactured devices, and those that can be applied elsewhere often use some form of visual feedback. The VersaTouch system, however, enables an arbitrary flat surface to act as an input device using an audio transmitter attached to a person’s fingertip, along with one or more receivers.
The plug-and-play system can not only track the position of one finger, but allows for multi-touch inputs and can tell between the fingers themselves by alternating transducer outputs. How hard one is pressing on a surface can be sensed as well, by measuring how the sound waves change based on force. Additionally, haptic feedback is available via the same transducer that sends a signal to the sensor array.
Consider, as shown in the video below, that one could draw a piano on a piece of paper, then use it to play a computer audio device after calibration. It could also be used to play two player games, with transducers mounted to each participant's finger.
As outlined in the project’s paper by researchers at the University of Auckland in New Zealand, the VersaTouch utilizes an Arduino Due to sense outputs from the finger transducers and a Teensy 3.6 is implemented to generate the acoustic signals. A MacBook Pro is then used to process the data and calculate finger positions through a program written in Java.