scientists have used magnets for everything. Protecting buildings from collapsing during earthquakes, levitating high-speed futuristic trains and for numerous other applications. Now, they are trying to levitate microchips. Engineers from the Massachusetts Institute of Technology ( mit ), usa , believe that using magnets to suspend these chips will halve the time it takes to etch a microchip by positioning silicon wafers more quickly and accurately.
Silicon wafers are usually placed under the lenses that are used to etch them by supporting them on a cushion of air. Each wafer is some 200 millimetres (mm) in diameter, so it has room for a large number of chips, each a 20mm square. The wafer has to be moved between about 30 mask printing shots for each chip. "These are us $3 million machines. You need to move chips rapidly because the time spent not printing is wasted,' says David Trumper, a mechanical engineer from mit .