actuators

noun

1. 1

   Something that actuates something else, especially a usually electric device that causes a mechanical device (i.e. a mechanism) to be switched on or off, for example an electric motor that opens and closes a valve

   “The mind is the actuator of the body.”

2. 2

   The mechanism that moves the head assembly on a disk drive

3. 3

   A relay that controls the flow of electricity