I'm trying to trigger a human touch in a capacitive touchscreen without the 'human' part. I've noticed that the negative pole of a battery triggers it if you are currently holding it. Or if you use the edge - why only the edge? - of a wire touching the battery and your hand. I also attached a wire in a metal bottle and connected the battery to it's end (with the battery touching the screen) and it also worked - but sometimes it also didn't.
The question is: How can I trigger a touch on the screen without the human touch, using objects from the hardware store?
I have almost no physics knowledge for this, so you guys have to tell me exactly what to do (which material, where to buy and etc).