Scientists have finally answered one of life’s great mysteries – why our fingers get wrinkly in the bath.

German researchers have uncovered the secret of the skin’s elasticity, and say it comes down to expandable lattices.

The team now say their research could lead to new treatments for skin complaints and more effective artificial skin.

Two physicists, Professor Roland Roth of Tübingen University and Dr. Myfanwy Evans at Erlangen University have revealed just why skin has this remarkable ability in the journal Physical Review Letters.

The outer layer of our skin absorbs water and swells up, forming ridges – but quickly returns to its old state when dry.

The swelling and absorption of water occur in the outermost skin layer, which is made of dead cells that are stacked in layers like bricks.

These cells are filled with a network of filaments made of the protein keratin.

These keratin strands interlock to form a three-dimensional lattice – which can increase its volume by five times when the strands stretch out, the researchers found.

Evans and Roth have shown how the structure could help skin cells swell and shrink.

Evans and Roth’s study could help to treat a number of skin disorders, and to create materials with skin’s remarkable properties.