To protect finger tips from copper splinters and to protect the copper plate from greasy finger prints I’m now looking for a material to lay over the top of the touch sensor. Recommendations are for a dielectric material (a substance that is a poor conductor of electricity, but an efficient supporter of an electrostatic field). Examples of these are glass, and most plastics. I’m testing with three pieces of acrylic, 1 clear, 1 red, 1 yellow, all 3mm thick. Intially the clear acrylic works best creating pretty smooth results. The red and yellow seem less effective and much more jumpy in the results they give. But when the pieces of red and yellow acrylic are pushed firmer on to the copper plate the results improve greatly. I think in the final design any colour of acrylic can be used but the thickness could be decreased to 1 or 2 mm . A coloured material as opposed to a clear material would visually look better as the circuitry could be concealed giving a more professional finish.

The development kit for the Qprox Qslide technology. We need to make a touch sensitive slider but instead of this 4cm example, we need one with a width of 1 metre.

To scale up the slider technology I scan in the dev kit and print out 1:3 .

I then lay this printout over the copper sheet and trace through with a knife. Once the design is lightly etched I can carve out the copper with a stanley knife…. this takes ages… .

I then mimic the dev kit, linking each area of the copper plate with wires to the QT1106 chip.

Run the demo and a little bit scketchy but definatly works!