After surfing for contless hours, i´ve discovered these simple, single faced, soldered by hand by a nice swedish developer.
Be advised that these chips (qt411, qt511) are being replaced by the much more powerful qt1106 (quantum had patent/manufacturer problems and interrupted prodution)
The number of plates can be increased for more precision, as long as the total sum (1.2 MegaOhms) of the series resistors remains the same.
For the pcb layout file (touch.zip):
You can also replace the plates for a zig zag pattern (oldest model, first suggested prototype) without the need for resistors like this:
This design is best presented on the ICs datasheets.
You can use an entire resistive membrane strip with 1.2 MegaOhms resistance in its total length, with contacts at 0/3, 1/3, 2/3, 3/3 of its length (maximum precision)