Hong Kong researchers create artificial skin that mimics bruising by turning purple when hit

Scientists in Hong Kong have developed artificial skin that bruises like the real thing. The material, called I-skin, could be used on artificial limbs to alert users they have damaged their prosthetics. It's embedded with a gel that turns from yellow to welt-like purple when subjected to physical stress. Volunteers wearing strips of I-skin on their fingers, hands and knees repeatedly banged the appendage against a wall, proving the'bruise' would appear if enough force was used. Scientists in Hong Kong have developed an artificial skin that will mimic the discoloration of a bruise if hit hard enough.