In a normal pencil, the lead is usually fashioned out of graphite and a clay binder. Graphite, as you may already know, is a form of carbon that is made up of layer after layer of the wonder ...

The basic 555 oscillator circuit is very simple ... drew a long thick line of pencil graphite on a piece of paper and mounted eleven wire loops attached to the circuit over his improvised resistor.

(Incidentally, pencil leads never contained lead; it's just that when graphite was first used in the 1500s, they thought it was lead ore, and the name stuck). With MIT's carbon nanotube pencil ...