Shape Changing Metal Crystals

Part of a new family of smart materials, this shape-changing metal crystal called ‘Martensite’ features two different arrangements of atoms, switching between them and changing shape when the material is heated or cooled to a certain temperature.

Known as an ‘active’ material, Martensite is made from an alloyed mixture of gold, copper and zinc. It is able to ‘remember’ and return to its original shape after it is deformed by temperature change. Importantly, it can change shapes tens of thousands of times when heated or cooled – without degrading like previously developed versions of Martensite. These previously developed versions of the material were made from alloyed mixtures of titanium and nickel that quickly built up internal stresses, breaking the material apart as a result.

Some smart material applications for this new Martensite include use in jet engines, electronics, and in medical applications such as ‘stents’ for holding arteries open or as frameworks for shaping healing bones.

As the material changes shape, its surface appears in a series of transforming microscopic river patterns. Watch this material in action here, with screen shots above.

This recent development of Martensite was recently reported in the journal Nature by scientists from the University of Minnesota. More information can be found here.