Nacre, the substance that forms the shell of many molluscs, is an extremely strong material, even though it is made only of brittle and soft components. This has inspired researchers at the Lawrence Berkeley National Laboratory in California to create a material with a similar architecture to nacre's but such superior toughness that its strength is comparable to that of aluminium alloys.
Robert Ritchie and his co-workers noted that the secret to nacre's useful properties lies in the stacking of its layers, which stops cracks from propagating. They recreated this feature using aluminium oxide and an organic polymer. The polymer was grafted (pictured) onto micrometre- and nanometre-scale ceramic pieces to help the two substances stick together.