BIOMATERIALS Intelligent glue
/Nature, 461 (2010)
Nature Volume: 465, Pages: 298?299 Date published: (20 May 2010)
Man-made glues are mono-functional ? their material properties are designed to stick one thing to another, and that's it. But in Nature Communications, Sahni et al.1 report that the 'glue' droplets that coat spiders' webs are multi-functional. Depending on the rate at which they are extended, the droplets act either as a viscous adhesive or as a rubber-like elastic solid.
Adhesive coatings are found everywhere. Think of the paint that covers walls, cars and ships' hulls; metals, such as gold and silver, plated on jewellery; and dyes that change the colour of fabrics and hair. These coatings have a variety of functions ? paint prevents barnacles and mussels from attaching themselves to ships' hulls, reducing drag on the ship and so improving fuel efficiency, whereas gold- and silver-plated surfaces are anti-corrosive.
Yet adhesive materials in nature do much more. Mussels, for example, secrete a substance that forms into 'byssus threads', by which they attach themselves to rocks, shells and even to feathers and fish skin (Fig. 1a). The threads must have a high degree of elasticity, or they would snap under the physical impact of lashing tides. But they need the additional property of adhesiveness, provided by a coating of a glue-like material, to anchor the mussels in place. What's more, the threads must maintain their grip under water, an environment in which most adhesives function poorly.
참조 1 : http://www.nature.com/nature/journal/v465/n7296/full/465298a.html