Biomimetics is the development of materials or machines inspired by the study of biological structures or processes. The book The Gecko’s Foot, published in 2006, gives many examples of such inventions inspired by natural phenomena—ranging from Velcro to cantilever bridges. In recent weeks there have been several news stories reporting new examples of materials design based on some unusual natural sources. Here are a few that caught my attention.
Hagfish Tights Anyone?
The poor old hagfish doesn’t seem to have a lot going for it. Millions of years old, it sits at the bottom of the ocean and the bottom of the evolutionary tree. A jawless, finless, spineless scavenger, not even considered fit to eat, according to Wikipedia, “owing to its repugnant looks, viscosity and unpleasant habits”. One of those unpleasant habits is exuding large amounts of slime, a defense mechanism that helps the hagfish evade predators. This slime is composed of protein filaments that have similar properties to spider silk—tensile strength and elasticity. Recent studies investigating the properties of hagfish slime have shown that it may be a viable natural alternative to synthetic fabrics. Unfortunately hagfish have not been bred in captivity so hagfish farming is not an option. However, the proteins in the hagfish slime are smaller than those in spider silk and so the hope is that they will be easier to clone and mass-produce. It’s early days yet, but the time may come when tights, vests, and other fabrics woven from hagfish “silk” become a reality.
Read more here
Parasites that Know How to Hang in There
Intestinal parasites of fish, thankfully, do not often spring to mind. However, a report in Science this week discussed an innovative application of the properties of one such parasite, Pomphorhychus laevis, which burrows into the intestine of infected fish by means of a retractable proboscis armed with hooks. Once inserted, the tip of the proboscis swells, attaching the parasite firmly to it’s host. Lovely.
The cool application of this is the development of new tools that may be able to replace surgical staples. Synthetic patches were developed studded with mironeedles tipped with a gel coating that expands when inserted into tissues, holding the patch firmly in place. The Science article describes use of such patches to hold skin grafts in place. The patches held the grafts better than sutures, were less damaging to tissue and less likely to cause allergic reactions than other materials.
Read more here
Don’t Let the Bedbugs Bite
A recent report in Wired Science describes how scientists have exploited the natural bedbug-trapping properties of kidney bean plant leaves to create synthetic traps. The plant leaves are covered in hair-like structures (trichomes) that impale the bedbugs feet, effectively trapping them on the leaf. To create their traps, the scientists made impressions of the leaf surface and then filled these moulds with various materials to create sticky copies that were able to trap the insects but did not impale them like the original plants. So, while not quite there yet, these synthetic materials show promise as an environmentally friendly alternative to pesticide treatments. (I still think throwing out the mattress might be my first choice.)
Read more here
The Source of Inspiration
What I like about all these stories is that they show how inspiration can be drawn from even the most mundane, ordinary, or obscure biological processes. Upon closer inspection, organisms as apparently uninspiring as hagfish, parasites and bean plants, turn out to be fascinating in their own right, and capable of surprising us with “innovative solutions” that just happen to have been around for a few million years, waiting to be noticed.