Microscopic repair machines have been a staple of science fiction for decades. Now that they have motors, they're one swim closer to reality.
Red Dwarf, Doctor Who, Metal Gear Solid and System Shock 2 have all relied on the idea of tiny machines(nanobots/nanites) that can alter the body's makeup at a microscopic level. The advancement of technology has already made microscopic electronics possible- the problem was getting the darn things to move.
Conventional electrical motors have a lower limit of the millimeter dimension where the resistance to movement becomes almost impossible to overcome. (Physicists can see a similar effect in surface tension.)
Now, research reported in the Journal of Micromechanics and Microengineering has demonstrated a motor about twice the size of a human hair. This latest research uses piezoelectric materials, which typically are crystals that expand and contract when voltage is applied to them.
Professor James Friend of the University of Monash, Australia, has already produced work last year on a motor about the size of a grain of salt, but they were still linear motors (back and forth). To perform real movement, the motors need to be able to rotate.
This has been overcome by building a "screw" into the motor, so that a forward motion at the right time also rotates the motor, in a similar way that bacteria move with their tails.
The prototype "spinning motor" is only a quarter of a millimeter wide, 70% smaller than its nearest competitor.