Scientists create non cuttable material less dense than steel

Inspired by some biological structures, such as fish scales. A team of researchers used similar design principles to create a "non-cuttable" metallic structure that's only 15% as dense as steel.

The material, dubbed Proteus, could someday be used to make super-strong and lightweight metal products, like armor and bicycle locks.

The team created Proteus by arranging microscopic ceramic spheres in a highly compressible Aluminum matrix of foam. When something like an angle grinder cuts into Proteus, the structure promotes a series of forward- and backward-moving vibrations. This movement excites the ceramic spheres, causing them to break down into particles. Then, these particles fill gaps in the foam matrix, making it even harder to cut through the material.

The ceramics embedded in this flexible material are also made of very fine particles which stiffen and resist the angle grinder or drill when you're cutting at speed in the same way that a sandbag would resist and stop a bullet at high speed.

Proteus is currently awaiting patent, and it could take years for the material to make it to market. But if these kinds of materials do become widely available, it could open the door for novel technologies — like impenetrable armor — that are inspired by biological adaptations millions of years in the making.