Shape Memory Alloys (SMA) wires are fascinating materials that have the ability to “remember” their original shape. Initially, they are malleable when heated above a certain temperature, allowing them to be deformed easily. However, when cooled, they return to their pre-set shape. This unique characteristic comes from the transformation between two solid phases of the material: martensite and austenite. The wire is typically made from alloys such as nickel-titanium, known as Nitinol.
When the SMA wire is heated, its atomic structure shifts, causing it to regain its original shape. This process is reversible, meaning the wire can go through multiple cycles of heating and cooling. The applications for SMA wires are vast. They’re used in actuators, medical devices, robotics, and aerospace technologies, where precise movement or response to temperature changes is required.