this based on the wonderful device made by Thomas Kim - a living god of Electrostatics who sits on the Right hand of the actual GOD Antonio Queiroz - http://www.coe.ufrj.br/~acmq/index.html
see more at
For explanation of induction goto http://www.coe.ufrj.br/~acmq/electrostatic.html and watch his videos
here's my not quite as good copy
Step 1: Two Metal Disks With Plastic Handles
So you need two metal disks . These were from a hard drive but you could cover a cd with aluminium with a couple of bits of plastic pipe as holders. I used two little foam sticky pads to hold the hanles on with.
Step 2: Influence Electrodes and Connecting Wire
A sheet of plastic (I used a A4 sheet) with two bits of foil 3" circles underneath stuck on . The disks are about 3" apart (6 cm)
I had a sheet of see through perspex (acrylic) but you could use a thin plastic cutting board.
The disks are about 2-3 inches (4-5 cm) across
On the opposite side of the sheet, stick a piece of foil like a bridge between foil disks say 1 cm by 5 cm
It needs to be bare metal on the top so don't cover it in tape. Use the sticky pads underneath the foil to stick it (or glue) to the plastic sheet
Step 3: Drink Cans
Put two drink cans (full are better as they dont fall over so easily) on a plastic sheet or polystyrene blocks
Tape the wire from the opposite foil disk to each can.
Tape a wire to each can from the foil disks, where there is bare metal (no paint) Scratch off the paint if necessary. there may be clear varnish so use some sand paper to be sure of a good connection. I used tape to hold them on.
Step 4: Clanger
Hang a little ball of foil from a cotton thread from a plastic bar (a plastic tube from a pen or something) between the cans. The cans should be about 2 -3 cm apart.
Step 5: Charge...!!!!! - How Does It Work
watch the video and charge!!!!!!
How does it work
Imagine the can on the left is slightly negatively charged (just handling the polystyrene will charge it which will induce a charge in the can)
This makes the foil pad its connected to by the wire negatively charged.
When you put the disks over the foil electrodes, electrons in the disks are repelled by the negative charge and flow to the other disk by the foil bridge. When you lift the disks one disk is negatively changed the other positive. When you touch the disks to the cans , you add some of that charge to the cans. By repeating the process you keep inducing more charge on the disks and the cans. The foil clanger gets attracted to the cans, when it touches on, it gets the same charge and is repelled and attracted to the other one (see Franklin Bells).
If it doesn't work, check you have good connections with the wires (clean the can and foil)
Put the foil, plastic sheet and polystyrene on a central heating radiator or blow some hot air from a hair dryer to make sure there is no moisture leaking charge away. Clean the plastic with cheap after shave or perfume (alcohol) hope it works, if it doesn't then let me know, we can fix it!