Engineers use science which, of course, is studying nature. But some engineers have always consciously studied structures in nature because the recognise that those structures have to be totally appropriate. Such structures are very complex chemically; they're made up of polymers, water and calcium salts but with many _other trace elements, produced as composites. Reinforced concrete is a composite - albeit a crude one. Recently the ICI team who studied the microstructure of the shell of the abalone and then lubricated cement with polymer to make MDF (macro defect free) cement, are achieving a big energy saving. Glass is made from silicone which is the most commonly occurring material in the world and theoretically, if we pull it as a fibre, is as strong as steel.

If we coat it with Teflon, which is one of the most inert materials known to man, we have an excellent material, both in strength terms and environmental change terms, which currently we now use for such things as stadium and various kinds of tent roofs. It is the way those composites such as Teflon-coated fibreglass are formed and their characteristics that are so fascinating. Firstly, many of them start deforming easily under load so allowing load distribution, and they then become progressively stiffer. This strain-dependent stiffness and the visco-elastic nature of the polymeric tissue is what makes them of such great interest, because they allow changes of potential energy to be stored temporarily as 'strain energy' and thus to smooth the loading.