So? I hear you say. I can think of a few which get floppy when wet... cardboard, paper etc. This is a new material based on a sea cucumber, which the New Scientist reports has a unique ability to go floppy in water and rigid when dry. Developed by Stuart Rowan and Chris Weder of Case Western Reserve University, Cleveland, Ohio, US, the material is a polymer made from two different compounds and shot through with microscopic cellulose fibres. "It's directly inspired by the sea cucumber," Rowan says. It is the precursor of materials which may be able to form soft clothing which will then morph into armour with the addition of a current or some other trigger.
As the developer of the new material says categorically that it was based on the abilities of the sea cucumber to go rigid in defence, which is known as biomimicry, it reminded me of the talk given at TED in which Janine Benyus talked about biomimicry: the ways in which we can learn from nature.