A micro linear actuator is a small or compact device that moves something in a straight line. They are used in compressed and confined areas to do things like open and close camera shutters, move small components in toys and scale models, and to power small machines that produce electronics. Aside from being much smaller than standard sized linear actuators, the internal mechanisms of the micro sized models are much the same.
Actuators work by converting one form of energy, generally mechanical, hydraulic, pneumatic, electrical, or electromagnetic, into a force that can lift or move an object. A mechanical micro linear actuator works by using some form of motor to turn either a screw and bolt design or a wheel and axel design. The screw and bolt lifts an object up and down; the wheel and axel design converts the rotary motion of the engine into linear motion — motion in a line — with belts or chains.
Hydraulic and pneumatic micro linear actuators work by using compressed liquids and gasses to control the movement of an actuator arm. The only difference between the two types is that one uses liquid and the other gas. Some form of servo controls the amount of gas or liquid pressure that is used to press the micro linear actuator arm to the designated position, precisely lifting the payload to the desired height.
Electric and electromagnetic micro actuators convert electricity into either force or magnetism that creates a force. Both electric and electromagnetic micro linear actuators are less efficient than other actuators. Due to their simple designs and low production costs, however, they are usually the type of micro linear actuator found on small electronic devices, radio controlled vehicles, and other compact toys and scale models.
A micro linear actuator generally has a much smaller load capacity than its larger counterparts. The use of different materials, such as composite materials and hard plastics, can impact the overall design and allow for larger payloads if needed. Capacity is usually measured using two separate calculations and the results are known as static load capacity and dynamic load capacity. Static load capacity is the ability of the micro linear actuator to lift a load and hold it in a specified position, while dynamic load capacity is the ability of the same actuator to move a payload at a certain speed.