The second prototype

Now that I know that the technique works, I decided that for my second prototype I will build the frame based on the FTIR technique which is shown in the picture below.

The infra red light from the leds will go into the acrylic pane and bounces up and down through the material. When a finger touches the acrylic the light gets frustrated and you will be able to detect a white spot, also known as a blob, with a camera that detects infra red light.

I am still waiting on the leds, but I already possess the acrylic pane. So for the next prototype I still need the aliminium H-shaped bar to build the frame, L-shaped brackets with screws to keep the frame together, wires to connect the leds with, resistors so the leds won't explode and a 12V adapter to give power.

I could buy most of the material at the following store:

Hubo
Badhuisstraat 95-101
2584 HE, The Hague (Netherlands)
(00)(31)703540360

There a bought the H-shaped aluminium bar (30x10x200), the L-shaped brackets and the screws for only € 11.10.

Now I need to go to an electric store to buy the wires, resistors and adapter.