A new shape-changing metal crystal is reported in the journal Nature, by scientists at University of Minnesota. It is the prototype of a new family of smart materials that could be used in applications ranging from space vehicles to electronics to jet engines.
Called a "martensite", the crystal has two different arrangements of atoms, switching seamlessly between them. It can change shape tens of thousands of times when heated and cooled without degrading, unlike existing technology.
Currently, martensite metals are made of an alloyed mixture of nickel and titanium.
They have the remarkable ability to "remember" their shape and even after being bent will return to their original form. For this, they are called "shape memory" metals.
They have been used in spectacle frames and brassiere wires, but also in surgery as frameworks for shaping healing bones, and as "stents" for holding heart arteries open.
Martensite metals change shape when heated or cooled through a certain temperature, when the atoms that make up their structure rearrange themselves in a sudden transformation.