But in the case of brittle materials like glass the route to strength was to prevent catastrophic crack- formation by embedding the glass in an elastic matrix. By itself the matrix was weak and deformable; by itself the glass easily shattered; but together the result was much more than the sum of its parts. The early result of this knowledge was, of course, fibreglass, a light, strong, easily formed material, used to make cars, boats - everything including the kitchen sink.
Much later, in a different part of the material science universe, researchers attempted to emulate the structure of a natural fibreglass-like material: abalone nacre or mother of pearl. This combines a hard, brittle material – calcium carbonate – with an elastic matrix of protein. The two materials are interleaved on a nano scale. After decades of work, this nanoprocessing has been replicated by a team at Cambridge University synthetically and the result is very like natural nacre.
But whether such a process will ever be a commercial route to tough materials is an open question.
Very recently, an ingeniously different route to toughened glass has been achieved by a team at McGill University, Montreal. Instead of building the composite layer by layer, the McGill team use top-down approach. Cracks are created in the glass by means of a laser and then a polymer back-filled into the interstices. This is fascinating because it has been assumed for a long time that such materials would have to be made by bottom-up processing. The new technique looks very like the kind that can be scaled up to industrial level. It is 200 times tougher than standard glass. Given glass’s importance in architecture, the new material should be eagerly pounced on.
‘Overcoming the brittleness of glass through bio-inspiration and micro-architecture’, Nature Communications 5, Article number: 3166 doi:10.1038/ncomms4166