Micromachinery

A spider mite next to a MEMS gear train.
A micromachine by Sandia is moved by a lit LED at Miraikan in Tokyo
A circuit diagram for a Sandia micromachine

Micromachines are mechanical objects that are fabricated in the same general manner as integrated circuits. They are generally considered to be between 100 nanometres to 100 micrometres in size, though that is debatable. The applications of micromachines include accelerometers that detect when a car has hit an object and trigger an airbag. Complex systems of gears and levers are another application.