Over millions of years, plants and animals have evolved materials with amazing properties - the sticky feet of geckos, spiders' silk, self-cleaning lotus leaves. Scientists are now learning to make products in the lab that imitate their properties; these are called biomimetics.
The beginnings of biomimetics
The most common application of a biomimetic product has been around since 1948 - Velcro! A Swiss engineer George de Mestral noticed how seeds of an Alpine plant called burdock stuck to his dog's fur. When he looked at them in a microscope, he saw that the seeds had hundreds of tiny hooks that caught on the hairs. A few years of experimenting led him to the nylon-based fastener which is now used commonly.
Spider silk: Also known as gossamer, spider silk is known to be stronger than steel (of matching thickness), while being extremely light. It has many potential uses, from use in bullet-proof jackets to wound dressings. The problem is a means to produce it commercially hasn't been found yet. Thanks to genetic engineering attempts are now being made to produce it in the milk of genetically-modified goats.
Gecko tape: Ever wondered how geckos (wall lizards) can walk on walls without falling down? Scientists have wondered about this too - so they examined it under microscopes. Tiny hairs on the geckos' feet together exert tiny forces of attraction that help them cling to walls. A team working at Carnegie Mellon University has now developed a sticking tape that works in the same way, using millions of tiny hairs made of a material called kapton.
Lotus effect: Lotus leaves are completely waterproof. Nothing ever sticks to them. That's because the surface of the leaf contains microscopic hairs coated with wax, that doesn't offer space for anything to stick, causing water droplets to roll off. This means the leaf is self-cleaning! The principle has been used to create non-stick paints, using nanotechnology to mimic the lotus leaf's microscopic surface.
Tiny hairs on the geckos' feet together exert tiny forces of attraction that help them cling to walls.
The variety of life is huge. There are many things that fascinate us. Fish that live in icy waters produce natural antifreeze that keeps them warm. Termites can control the temperature of their nests by re-arranging the mud walls. Some kinds of bacteria thrive in harmful environments. They do this by producing enzymes that break down toxic substances.
Material scientists are increasingly interested in studying how these phenomena work, hoping to use the knowledge to create new materials for use in energy-efficient building homes, better materials for artificial limbs, cleaning up pollution and much more.