By mimicking the skin of the sea cucumber, US scientists have developed a remarkable new material that can change within seconds from a hard plastic to a soft rubbery texture. They hope it might eventually be used to make medical implants.

Sea cucumbers, large slug-like animals that live on the ocean floor, are normally soft but in response to a threat they can rapidly harden their skin into a type of body armour. The switching effect depends on a network of biological nano-fibres, which can either be connected (hard) or disconnected (soft).