Mini SMA (shape memory alloy) Actuator

This is a Shape Memory Alloy actuator, it has an SMA spring and a conventional spring, it works on the pricipal that SMA materials change their shape according to the temperature. In this case the two springs move a little arm. In this way you can have a temperature sensitive actuator which requires NO electricity and NO external control.
In addition to the 3D printed parts you will need:

• 2 Screw GB/T 13806.1-1992 Type B; M1,4 x 1,8 mm
• 1 SMA spring (choose the working temperatures according to your needs as long as the inner diameter of the spring fits around the coil support)
• 1 Normal spring which has about 50% the force of the SMA spring

And I reccomend to add oil or some type of lubricant between the linkage and the coil support