A flexible material that instantly hardens into armour upon impact will protect US and Canadian skiers from injury on the slalom runs at this year’s Winter Olympics.

The material, known as d3o, can be worn under normal ski clothing and can replace bulky arm and leg guards that skiers have to put on to protect themselves from poles placed along the slalom run.

Although the exact chemical ingredients of d3o are secret, d3o Labs says the material is synthesised by mixing together a viscose fluid and a polymer. Following synthesis, liquid d3o is poured into a mould that matches the shape of the body part it will protect.

Under normal conditions the molecules within the material are weakly bound and can move past each with ease, making the material flexible. But the shock of sudden deformation causes the chemical bonds to strengthen and the moving molecules to lock, turning the material into a more solid, protective shield.

Further developement may lead to another potential application of the system: sound-proofing. The propagation of sound waves should generate a similar strain to an impact, so it may be feasible to create a material that becomes more sound proof in response to increasing noise.

Via New Scientist. See also Der Spiegel‘s article on high-tech equipement for Winter Olympics athletes.