Researchers create metal memory foam

In the world of commercial materials, lighter and cheaper is usually better — especially when those attributes are coupled with superior strength and special properties, such as a recently developed material's ability to remember its original shape after it has been deformed by a physical or magnetic force.

Known as 'magnetic shape-memory foams', the material consists of a nickel-manganese-gallium alloy, whose structure resembles a piece of Swiss cheese with small voids of space between thin, curvy 'struts' of material.

The struts have a bamboo-like grain structure that can lengthen up to 10% when a magnetic field is applied. The alloy material retains its new shape when the field is removed, but the magnetically sensitive atomic structure returns to its original structure if the field is rotated 90<0x00B5> — a phenomenon called 'magnetic shape-memory'.

"It's the first foam to exhibit magnetic shape memory. It has great potential for uses that require a large strain and light weight such as space applications and automobiles," said NSF program director Harsh Deep Chopra.

"These materials are able to do more with less material — given their foamy structure — and provide a sustainable approach to materials development."