Number 145 (Story #4), September 28, 1993 by Phillip F. Schewe and Ben Stein MICROSCOPIC STEAM ENGINES can deliver up to 100 times the power of comparably sized electrostatic micromotors. Sandia physicist Jeffry Sniegowski has built a tiny motor only 6 microns by 2 microns; sitting on a wafer, the device consists of a micropiston moving through a silicon bore. Power comes from a water bubble made to expand and contract by heating. Potential applications of the motor may occur in areas where high-precision alignment or positioning are important, such as micro-surgery or micro- manufacturing. (Science News, 25 Sept. 1993.)