Micro-submarine. Light micrograph of a micro- submarine made by computer-aided lasers. A computer guided a laser through a reservoir of an acrylic liquid according to the submarine's specifications. The beam caused the liquid to polymerise and solidify as it passed through, building up the submarine in layers 10 micrometres thick. This process allows tiny components to be made accurately. This submarine is 4mm long. Tiny machines such as this could be used for detecting and repairing defects in the human body. This submarine was made by microTEC, Duisburg, Germany. Magnification: x13 at 6x7cm size.