Invisible Pink Unicorn writes: "Conventional kevlar vests and body armor stop bullets by spreading out the bullet's force over a larger area. While this does stop the bullet from penetrating the skin, blunt force trauma can still lead to incapacitation and damage to critical organs. Researchers at the Centre for Advanced Materials Technology, University of Sydney, say that the elasticity of carbon nanotubes may put an end to this by using the energy of the initial impact to rebound the bullets, essentially canceling out the force normally felt by the wearer. From the Telegraph: 'The team tested carbon nanotubes
... by bombarding them with diamond bullets travelling at speeds varying between 1000 and 3500 metres per second, revealing the conditions when the bullet could bounce back. Based on their findings, they calculate that six layers of woven nanotube yarn — about 600 millionths of a metre thick — may protect the wearer from a revolver bullet, so that it bounces off.'"