This illustration shows how an Atomic Force Microscope (AFM) is used to image a line of graphene made by a pencil. The scale spans ten orders of magnitude, from the microscope and pencil to the atoms that compose the scanning probe and pencil line. As the viewer zooms into the line, graphite flakes, and eventually a single layer of graphene, become visible. On the AFM, a silicon cantilever with a sharp atomic tip and a laser with a photodiode measure the up and down motion as the probe maps out the graphene sample.
"Exploring Materials - Graphene" is a hands-on activity in which visitors use tape and graphite to make graphene and test the conductivity of graphite. They learn that graphene is a single layer of carbon atoms arranged in a honeycomb pattern. There are two versions of this activity, one that uses an LED to test the conductivity and one that uses a buzzer.