What can we learn from sharks and slime mould: Bionics in industry and material design

Fuel-efficient aeroplanes that have the grace of predator fish, stable lightweight constructions with a honeycomb design, or hook-and-loop ties that were inspired by burrs: these are all examples of bionics, which is when natural phenomena are used in technological applications.

Bionics is long established as a field of research and has become part of our daily lives. The Association of German Engineers (VDI) defines bionics as “research and development approaches (…) that are intended to create a technical application, and which are based on knowledge derived from the analysis of living systems in order to find solutions, inventions and innovations for technical systems.”

The goal here is clear: engineers hope to benefit from biological phenomena to derive creative and efficient solutions for technical challenges. The idea behind this approach is that over billions of years of evolution, nature will have already found a solution to their problem. One example of this approach being put into practice is the development of lightweight and more durable products and materials. In addition to these benefits, the engineers hope to save both costs and raw materials, as nothing else on the planet uses resources and energy as efficiently as nature itself.

None of these thoughts are a modern invention, but can trace their roots back to the late Middle Ages. Shall we digress for a moment? Certainly.

One of the pioneers in bionics was the legendary polymath, Leonardo da Vinci (1452 - 1519). By observing and studying the flight behaviour of birds and bats, he hoped to be able to use this knowledge to develop flying machines. Unfortunately, period materials were not stable enough to make the dream of flight become a reality. Despite this, da Vinci knew:

Human subtlety will never devise an invention more beautiful,
more simple or more direct than does nature because in her inventions nothing is lacking,
and nothing is superfluous.

Excerpt from Leonardo da Vinci’s “Codex on the Flight of Birds” which can be seen in the Bibliotheca Reale in Turin.

Today, da Vinci’s approach is called the biology push, a method where engineers take findings from biology as a starting point from which they begin to develop technical solutions. Well-known examples are hook-and-loop ties and the Lotus effect® for self-cleaning surfaces, which was derived from lotus flowers. The opposite of the biology push is known as the technology pull. In this approach, engineers assume a technical problem and look for a solution in nature. A good example of the technology pull is anti-fouling coatings for ships which slow the growth of algae and mussels on the hull of the ship. These coatings are similar in design to shark skin which is immune to these issues. But this isn’t all we have been able to derive from sharks...

Using shark technology to break a world record: In the year 2000, swimmer Ian Thorpe set a new world record in the FINA Swimming World Cup leg in Berlin. What was special about this was that Thorpe wore a swimsuit that covered his entire body, the material of which was also similar to shark skin. The surface structure was covered in many tiny “teeth” which reduced the water resistance and potentially provided the swimmer with the advantage needed to post the best time.

Bones as an example for lightweight construction: It is well known that the honeycomb form has become synonymous with lightweight construction, particularly in 3D printing. However, humans are also making a significant contribution to this topic – with our bodies. Gustave Eiffel studied the structure of human bones, which consist of countless cavities and trabeculae. These help generate stability where stresses are applied – a perfect of example of nature creating material efficiency when required! At the end of the 19th century, the Frenchman then integrated these findings into his design of the Eiffel Tower with its characteristic rib-like structure.

Slime mould for more efficient traffic: Slime mould (physarum polycephalum) is one of the oldest life forms on our planet. To be perfectly accurate, it is not really a mould, but a single-celled organism. While this may sound primitive, slime mould is really anything but: when searching for food, the slime mould spreads out like a web – and is always able to detect the shortest path between two points. The nodes of this organism’s network are extended to the minimum possible extent. In this case, we can see both lightweight construction and a perfect sense for navigation, making slime mould a very interesting research object when planning efficient transport systems.

A model of perfect navigation: the web-like structure of slime mould.