A group of students at Imperial College London have invented what they call 'bruise trousers,' a set of pants that release a magenta dye when the wearer experiences a hard impact below the waist. The trousers are targeted towards disabled athletes, some of whom cannot detect pain and injury in their legs.
The trousers are made of a breathable Lycra fabric which is lined with strips of pressure-reactive film. The film is situated in pockets strategically placed over the thorax, pelvis and leg bone areas. Upon hard impact, the film releases a magenta dye from micro-capsules that are embedded within it. The amount of dye released is directly proportional to the strength of the impact.
The students are hoping to eventually develop an entire line of sports apparel with the same capability.