Smart dust. Computer artwork of particles of smart dust (red) searching for cancer cells in the human body. These microscopic particles consist of silicone that has been chemically modified to target and stick to a pre-determined type of surface, in this case cancer cells. Each particle has two differently coloured reflective surfaces, only one of which sticks to the target. The other surface acts as a marker, indicating that the correct target has been located. The particles of smart dust can also be engineered to process data and communicate with each other and a base station. They can also carry small cargoes such as deoxyribonucleic acid (DNA), viruses and bacteria.