I have been wondering this for a while now... My laptops touch-pad is very nice, you can be incredably gentle with it unlike some others I have tried out. But why do they only work with skin contact?

Are they heat sensitive as well as pressure? I tried warming some things up to test them but to no effect. Or for instance a thin piece of material over the finger and it still works, but is less sensitive, but anything other than a finger under the material and nothing happens.

pressure, heat, even electricity of your body.

So why do they need to detect that? surely just pressure would work... or would that not be as sensitive?

The big question is how to touch screens work. I understand it is something to do with lasers

magic and jelly beans, next question

lmao :P Yeah, that could be it :P

http://en.wikipedia.org/wiki/Touchpad

Good question.

I think it has something to do with your bodies electricty.... same goes for the ps3's touch pad for on and off. Try it with a sock it won't work try it with a penny while touching the penny and it will.