A Linear Actuator is a device that creates linear movement. The most common methods of achieving linear actuation are using mechanical and hydraulic power. Many linear actuators are driven by a non linear motion. There are various types of linear actuators but probably the most widely used is the mechanical actuator. Mechanical linear actuators operate by converting rotary movement into linear motion. Various mechanisms make this possible such as the screw. Simple mechanisms which use this means of movement are the everyday screw jack which when rotated produces a linear motion to the lifting assembly. Other applications include hoists, winch, rack and pinion, chain drive and belt drive. By rotating the wheel/axle etc. the linear member moves. Cam actuators operate on the same principle as the wedge, but gives limited linear travel. As the wheel like cam rotates, it eccentric shape produces thrust at the bottom of the shaft. There are various other linear actuators which use power to operate and these can include hydraulic actuators, electro-mechanical actuators, pneumatic actuators and piezoelectric actuators, all of which are used to produce a linear motion.