Touch sensors?

Question

Sensors

Are there affordable and inexpensive touch sensors that can not only record the fact of contact, but also track the percentage of the touched area?
For example, if the pad has the shape of a circle with a diameter of 6 mm, can such a sensor determine the percentage (or any other digital indicator) of overlapping the area of ​​​​this circle by touch (finger)?

Answer 1

The simplest and cheapest touch sensor can be made by yourself. Its cost will be equal to 50 kopecks (Ukraine) ~ 2 Russian rubles. It is impossible to determine the touch area, although you can try: we physically divide the contact area into smaller parts and connect a separate sensor to each, the approximate area is determined by the sum of the “triggered” sensors.
The sensor is the old well-known transistor KT315 (or any other with the required parameters) - we solder the base to the contact pad, and let the collector and emitter go to the amplifying stage in the key mode.
And google for the phrase "Capacitive relay" - maybe it will suit you.

Answer 2

Thank you. Something more modern is needed. I want to make a specific musical instrument.

Answer 3

Or maybe just a photodetector? The more tightly you cover it, the less light gets in.

Answer 4

You can make a resistive sensor: two contact terminals, a finger between them. The larger the contact area, the lower the resistance.
But it will fail due to sweat. If you take it, then it is ready-made, manufactured by prom. contact pad method.