Smallest submarine - medical use

microTEC, from Duisberg, Germany, produced a micro-submarine which measures 4mm 0.157in in length and 0.65mm 0.025in in diameter, using computer-guided lasers. Laser light caused the acrylic liquid used to construct the submarine to polymerise, building the vessel in layers 10 micrometres thick. It is hoped that nanorobots such as these will be used to travel to sites of blockage or damage in blood vessels and repair them from within.