There are plenty of cases and accessories designed to protect an Apple iPhone mobile phone. But Japanese car maker Nissan thinks its experience with exterior auto paints could make a smart phone case that heals itself of scratches.

The Nissan Scratch Shield is a prototype case for Apple iPhones that is made of the same polymer material which Nissan uses to coat its vehicles, such as the Murano SUV and the 370Z sports car.

The unique property of the polyrotaxane material, says Nissan, is:

...that when damage occurs to the coating in the form of a fine scratch, the chemical structure is able to react to change back to its original shape and fill the gap - 'healing' the blemish.

Nissan's press release says a batch of prototype Scratch Shield cases have been produced for "testing with selected journalists and customers" and it may produce the smart phone cases later this year if there is demand for a scratch-proof scratch case.

World's First Self-Healing iPhone Case [Nissan press release]