The prefix "micro" means very small. For example, "microtube" means a very small tube. Some sculptures are smaller than toothpicks. These are called microsculptures. Micromotors, then, are very small electric motors. One motor, manufactured by the Flexmotor Corporation, is 2 millimeters wide by .6 millimeters thick.This is about the size of Abraham Lincoln's eye on a penny. Its thickness is about half that of a penny. Looking at it another way, it can ride on the back of an ant. This motor spins at 3,000 rpm, and the maximum voltage it can handle is 2 volts.
Technology has advanced to a point where micromotors can be cheaply produced. However, in 2011 they are a recent development, so all the uses have not been explored yet. "Popular Science Magazine" speculated that flying microrobots are possible with micromotors. These robots would be about the size of a gnat or flea. Combined with wireless microcamera systems, they could be used for inspection of extremely small spaces, such as the inside of a small tube in a nuclear reactor.
Another use could be space exploration, according to researchers Mr. Bullock and Mr. Angle at the Massachusetts Institute of Technology. Its easier and cheaper to launch a very small probe than it is to launch a large probe. A robotic probe, about the size of cell phone, could travel along a planet's surface and send back pictures and soil-sampling data. Micromotors would drive the wheels and move the sampling arm.
A linear motor does not spin a shaft. Rather, it moves a shaft back and forth. In 2011, linear micromotors are a recent development. New Scale Technologies Incorporated claims to have the world's smallest linear motor. The motor and controller unit both fit on the head of a pushpin. Since this is a new development, all of its uses have not been fully explored.
Far smaller than micromotors, a nanomotor can only be seen by a powerful microscope. In 2003, physicists Alex Zettl et al., at the University of California made a motor that is only 500 nanometers big. To put this into perspective, 300 of the motors can fit in a human hair, according to Dr. Zettl. Dr. Zettle also stated that as research goes on, his team will be able make a motor five times as small. In 2011, research is ongoing on nanomotors and how to utilize their fullest potential.