Ship-in-a-bottle kit on a microchip
Sometimes physicists resort to tried and trusted model-making tricks. Scientists at the Max Planck Institute for Metals Research, the University of Stuttgart and the Colorado School of Mines have constructed micromachines using the same trick that model makers use to get ships into a bottle where the masts and rigging of the sailing ship are not erected until it is in the bottle. In the same way, the scientists link the valves, pumps and stirrers of a microlaboratory to create a micro device on a chip. To do this, they introduce colloidal particles - tiny magnetizable plastic spheres - as components into the channels on the chip. A rotating magnetic field is used to link the components into larger aggregates and set them into motion as micromachines...