Nature's composite materials are far superior to our own. Bone (collagen and apatite), wood (cellulose and lignin) and mother of pearl (protein and calcite) all combine strength with enviable toughness. Mineral-filled polymers are far inferior.

The secret, of course, is in the microstructure. The hard particles of a natural composite have a closely defined shape and packing. And the ‘glue’ holding them together has an ideal tenacity. Chemists are quite good at crystallizing fine particles in desired shapes, such as needles or platelets. But how to pack such particles properly in an adhesive binder?

Daedalus has a novel answer. He wants to pack the particles dry, by vibration and compaction, possibly in an electric field to encourage their orientation, and add the organic component later. It will be a gaseous monomer — ethylene or propylene are the obvious choices for pilot work. Its low viscosity, independent of pressure, will let it percolate freely between the particles even under enormous pressure. Cunningly, Daedalus will then initiate polymerization with X-rays. The gas will hardly absorb them at all. But the mineral particles will block them, liberating photo-electrons copiously on their surfaces. So polymer chains, initiated by and anchored to these surface sites, will start to grow out into the monomer. Many of them will hit another particle, and will terminate on and anchor to it, binding the two particles together by a strong polymer chain and giving ideal adhesion.

But adhesion is only half the problem. A tough composite must be flexible as well. Fortunately, a polymer chain grows in a wandering, self-tangling way. Two particles tied by such a chain could separate a little, untangling the chain slightly. When the load came off, the chain would re-tangle, hauling them together again.

Daedalus's new composites will challenge bone, ivory, jade and mother of pearl on their own ground. Light and tough, they will be moulded like Bakelite, or tooled into shape from billets. They will make wonderfully robust dishes, handles, ornaments — all the small change of material life. And with an elasticity and tenacity so similar to bone and dentine, they will be ideal for false teeth, hip joints, and implants of all kinds.

The Further Inventions of Daedalus (Oxford University Press), 148 past Daedalus columns expanded and illustrated, is now on sale. Special Nature offer: m.curtis@nature.com