The world's smallest guiter is the size of a red blood cell.

The world's smallest guiter--carved out of crystalline silicon and no larger than a single cell--has been made at cornell university to demonstrate a new tecnolygy that could have a variety of uses in fiber optics,displays,sensors and electronics.
The "nanoguiter"--made for fun to illustrate the tecnology--is that one of several structure that cornell researchrs believe are the world's smallest silicon mechanical device.