Scientists are making microscopic gears, turbines, and other components of micromachines--tiny motorized systems that might one day be built into semiconductors or placed inside the human body. But many of the efforts involve silicon components so thin they can't generate much torque. Yet, fashioning thicker metal microstructures often requires exotic and expensive equipment--such as X-ray synchrotrons--available only to a few top labs.
Georgia Institute of Technology electrical engineer Mark G. Allen has an alternative. Allen's group uses conventional microelectronic lithography to etch gear patterns into a common plastic. These molds are filled with copper or nickel. So far, the group has created metal gears about 300 microns wide and 50 microns thick--a human hair is 100 microns in diameter. Allen says the gears should have enough torque for many uses--such as in motors that could help precisely position fiber-optic lines into telecommunications chips.