Shape memory alloys By Jaz Thompson

A small definition A shape memory alloy (SMA, smart metal, memory alloy, muscle wire, smart alloy) is an alloy that "remembers" its original, cold, forged shape, and which returns to that shape after being deformed by applying heat. This material is a lightweight, solid- state alternative to conventional actuators such as hydraulic, pneumatic, and motor-based systems. Shape memory alloys have applications in industries including medical and aerospace.

Example in aircrafts Boeing, General Electric Aircraft Engines, Goodrich Corporation, NASA, and All Nippon Airways developed the Variable Geometry Chevron using shape memory alloy that reduces aircraft's engine noise. All of Boeing's new aircraft will be equipped with this new technology.

Example in robotics There have also been limited studies on using these materials in robotics (such as "Roboterfrau Lara" [2] ), as they make it possible to create very light robots. Weak points of the technology are energy inefficiency, slow response times, and large hysteresis. Nitinol wire is also used in robotics (e.g. the hobbyist robot Stiquito) and in a few magic tricks, particularly those involving heat and shapeshifting.

Other examples include Piping Optometry Orthopaedic surgery Dentistry

Microscopic and Macroscopic Views of the Two Phases of Shape Memory Alloys

Microscopic Diagram of the Shape Memory Effect