Silicon is a brittle material that can be coated with other materials to make a very tiny circuit, just like a printed circuit. The circuit is called an integrated circuit. A chip with a very complicated integrated circuit may be less than one square centimetre in area.

The circuits on microchips are used to operate computers, electronic games and household appliances such as washing machines and television sets. The world's largest user of chips is the motor car industry. Most modern cars have chips inside them.