A futuristic 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 lightweight bendable material, known as d3o, can be worn under normal ski clothing. It will provide protection for US and Canadian skiers taking part in slalom and giant slalom races in Turin, Italy. Skiers normally have to wear bulky arm and leg guards to protect themselves from poles placed along the slalom run.

Skiwear company Spyder, based in Colorado, US, developed racing suits incorporating d3o along the shins and forearms and offered members of the US and Canadian Olympic alpine ski teams the chance to try them out several months ago. "Now they love it and won't ski without it," claims Richard Palmer, CEO of UK-based d3o Labs, which developed the material.

Although the exact chemical ingredients of d3o are a commercial secret, Palmer 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.

Brief impact

The resulting material exhibits a material property called "strain rate sensitivity". 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.

In laboratory testing, d3o-guards provided as much protection as most conventional protective materials, its makers claim. But Phil Green, research director at d3o Labs, says it is difficult to precisely measure the material's properties because the hardening effect only last as long as the impact itself.

However, Green believes it may be possible to alter the properties of d3o for new impact-protection and anti-trauma applications. "There are certainly opportunities to dabble with the chemistry and enhance the effect," he told New Scientist.

Another potential application may be 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. "It could have some very interesting, unexplored properties," Green says.