The tinker.it blog (and site) has tons of great projects for designers and artists, like this one a Multitouch table –

This is an experiment based on “frustrated total internal reflection” aka FTIR. This is a very basic demo and we did it just to see how it work and it took us just 4 days!

tinker.it » Blog Archive » multitouch table experiment – Link.

  • DGary

    saw a massive APR based touchscreen at an Industrial Design expo in Miami a few years back that I thought was the next big thing, kind of surprised APR didn’t take off more, since its just a few piezoelectric transducers and some signal processing and sample matching you could turn any sound transmitting surface into a touch screen

    only downside of APR is it is based on sound, so it only works on touch, not drag, its like passive surface wave

    although… I don’t see why surface wave couldn’t be used, same concept but with transmitters as well.

  • charliex

    I’m curious what happens if the plexiglass is scratched ?

    the APR stuff looks interesting too, i wonder how resistant it is to external sounds.


  • DGary

    FTIR with a scratch should cause a “touch”, unless the application handling processing is written as to handle them, like an “alignment” of sorts

    APR handles scratches very well, even seen some systems that could handle cracks although I imagine again, its more about signal processing and tuning than anything specific with the hardware design.

  • Gajender

    i am very excited to khow that what will happen if plexiglass scratches.

  • MaverickGizli

    i wonder how resistant it is to external sounds