Shape Memory Alloys (SMAs) are special materials that can return to a predetermined shape when heated above a certain temperature. These alloys typically consist of metals like nickel and titanium, which undergo a phase transformation that allows them to "remember" their original shape. When deformed at lower temperatures, they can revert to their original form when warmed, making them useful in various applications. SMAs are used in many fields, including medical devices, robotics, and aerospace engineering. For example, they can be found in stents that expand in the body when heated or in actuators that move parts in response to temperature changes. Their unique properties make them valuable for innovative designs.