Question

Design one simple experiment to verify graphene sheet is a good electric conductor.

Answer 1

You can experiment with the electrical properties of graphene compared with graphite, the three-dimensional array produced by stacking and bonding sheets of graphene. You will need the following materials:

• pencil (your source of graphene and graphite)
• paper
• battery (e.g., 9-volt battery)
• LED
• insulated wire leads
• 330 ohm resistor
• Connect the positive terminal (+) of the battery to one side of the resistor.
• Connect the resistor to one end of the LED light.
• Connect the other end of the LED to an insulated lead.
• Attach a lead to the negative (-) terminal of the battery… but don’t connect the other end to anything.
• Use the pencil to draw a thick box on the sheet of paper. The pencil ‘lead’ is graphite. Make the box a few inches long and about half an inch wide. Shade it in as dark as you can. Graphite is an excellent electrical conductor, so you just drew a sort of carbon wire onto the sheet of paper.
• Touch the ends of the two leads (one attached to the LED and the other attached to the negative terminal of the battery) to the ends of the graphite box. What happens? Did the LED remain dark or light up? What happens if you move the leads closer together and further apart?
• You can make graphene by stripping away the layers of graphite. One easy way to do this is to erase most of the graphite. You’ll still have some graphite, but also some single-layer sheets of carbon or graphene. Erase part of the box, connect the leads and see what happens.
• If you like, you can draw other paths with the pencil and see what happens when you connect the leads to the ends of the paths. Try short lines, long lines, zig-zag lines… whatever you like!