Has your mouse broken down and you need a quick fix? Or perhaps you like the look of Apple’s Magic Trackpad, but you don’t want to pay mega bucks? AfroTech forum user Dr. West devised a touchpad made of, well, a piece of paper shaded with pencil with an electrical current running through it.
Using an Arduino controller, Dr. West connected four voltage dividers to the corners of a square piece of paper. The paper was heavily coated with graphite from a pencil–using materials such as aluminium foil would be too conductive. An anti-static wrist strap grounds the user’s hand from the current, thus completing the circuit, and preventing the user from getting shocked (Zap!).
The graphite makes a good conductor, so the Arduino board can then pick up finger movement, and tell the computer to move the pointer onscreen. Check out the video above to see the touchpad in action.