iPod sends electric signal to ur body....;-)
Sorry for again writing abt iPod. Just wondered how it is designed & found some thing interesting.
Do u know that the click wheel wont work if you use any plastic material to move around the wheel ( use cap of a pen to test this) ? U c it sends electric signals from the base and for the click wheel to work, the object it touches should be a conductor.We are good conductor and hence our finger does the magic.
But why when a paper click is used it doesn’t work? Good question isn’t it. The area of touch also does matter. The more the area of touch more electric cloud ( they call it as capacitance ) is created under the wheel which is sensed by electric circuit.
More details about that here.