A mini actuator is a somewhat ambiguous term to describe any type of very small actuator, a device that transforms some type of power into motion. Actuators typically run on electric current, hydraulics, or compressed air and use simple mechanical devices or electric motors to create some type of motion, such as opening or closing switches or valves. Actuators, regardless of size, are grouped into two broad categories: rotational and linear. Linear actuators provide motion in one direction, such as an automated arm to open a window louver, and rotational actuators convert power into some type of rotational or orbital motion such as turning a ball valve. A mini actuator is any very small actuator that is designed specifically to perform its task in a minimum of required space.
Actuators are an extremely varied class of devices and are used for thousands of applications and machines. They open doors, valves, remote locks, power windows in automobiles, and trays on DVD players and computer CD-ROM drives. Some actuators may be large and powerful, such as those that are used to open the doors on canal locks or spillways on dams. Most actuators use electric motors, compressed air, or hydraulic cylinders to convert power into motion, and while a mini actuator can use any of these power sources, most are electric.
When a device or machine is designed with an emphasis on compactness or its size is restricted by space considerations, engineers may rely on mini actuators, some of which can provide significant mechanical force. A mini actuator is an actuator that has been designed to convert power into some kind of motion while taking up as little space as possible. They can be linear, rotational, or piezoelectric, a type of actuator that relies on the tendency of certain kinds of crystal to change shape when subjected to an electric current.
The classes of actuators in terms of size are not defined by any kind of convention or hard and fast rule. The term mini actuator is used by manufacturers as a kind of buzzword to indicate that a particular product is of compact size. They do differ from microactuators specifically, however, in that a microactuator is a type of microscopic actuator that is often employed in circuitry.