Shape Memory Alloys SMA attracts more and more interest and nowadays many research centers are working on developing more accurate and applicable actuators. A tangible effect of using SMA materials is considerable simplification of the constructions used so far, which entails obvious economic benefits. Along with the increase in the volume of production and decrease in the cost of production, SMA materials become increasingly available on the consumer market. In the article the use of SMA wire to build and control linear position actuators was presented. The SMA actuator is characterized by one of the highest in technology weight ratios, which describes the ratio of maximum external load to its own weight. It allows for building miniature devices which are extremely efficient. Generally SMA wires are applied as on-off objects. After initial research and building several prototypes the gear transmission was chosen. It was decided to realize an actuator which can work in both directions of displacement, and so allow for the elimination of a return spring, which is a unique solution.