Nanotechnology gives us the ability to make incredibly small objects. Some of its methods came from microchip technology. Shapes are printed on to the surface of silicon, which is then etched away to make microscopic wheels or even micromotors. Other methods work with individual atoms to make even smaller objects. Although it is not used much yet, nanotechnology promises a future in which machines too small to see are part of our everyday world.
In a few years’ time, silicon microengines could replace laptop computer batteries. Liquid fuel burns inside the tiny combustion chamber to spin a central rotor, which turns a generator. A tank of fuel for the engine would weigh no more than a standard laptop battery, but could power the computer for 10 times as long.
Scientists are already working on structures thousands of times smaller than micromotors. To make them, they use atoms like builders use bricks. One day they might be able to build robots as small as the cells that make blood red.
Carbon atoms can form molecules shaped like tubes and also ball-shaped molecules, known as buckyballs. Carbon nanotubes can be either electrical conductors or insulators, and are 10 times stronger than steel. The biggest nanotubes are only a millimetre or so long, but they are ideal for building microscopic electrical machines.