A substance or device that supplies energy.
In order to make a micromachine to run on its own, an energy source
must be built-in. By the use of polymer solid electrolytes, a thin battery was developed, which is
already in use. However, the energy stored in such a small battery may be insufficient. Any way to
tap energy from the environment is desirable such as solar cell. For in vivo use micromachines,
adenosine triphosphate ( ATP) is expected as an energy source.