Last year we saw researchers adapt these lightweight materials to stop various forms of radiation in their tracks, and now the same team has ramped things up to offer protection from something with a bit more force: an armour-piercing bullet, which was turned to dust on impact.

In its most simple form, foam metal is made by bubbling gas through molten metal to form a frothy mixture which then sets as a lightweight matrix. This leaves a material that offers a lighter alternative to conventional metals, while still maintaining a comparable strength.

Afsaneh Rabiei, a professor of mechanical and aerospace engineering at North Carolina State University, last year produced a foam metal shield that could block X-rays, various forms of gamma rays and neutron radiation, giving it potential as a lightweight alternative to the bulky radiation shielding currently available.