Biomimicry or bio-inspired design?
The systems that we design and engineer at Animal Dynamics are inspired by the way nature does things. As a spin-out company from the University of Oxford Zoology Department, our designs have a strong basis in the study of evolutionary biomechanics, a field to which our co-founder Adrian Thomas has dedicated his academic career. That is not to say, however, that our designs are biomimetic, as is so often assumed. In this post, we look at this key difference in our work.
What is biomimicry?
Biomimicry is the study of biologically-produced substances, materials, mechanisms and processes for the purpose of synthesising products that copy them. The premise of biomimicry is that living organisms have evolved to be well-adapted to their environment through the process of natural selection. Therefore, replicating the solutions found in nature enables synthesised products to also be well-adapted to their intended use. In other words, nature has solved this – let’s copy it.
How is what we do different?
Unlike biomimetics, we don’t imitate biological structures for the design of our vehicles. Instead, we look at the underlying mechanism, the engineering behind nature’s solutions. Take the canopy of our Stork vehicle range, for example – we have not designed it to be a copy or imitation of a bird wing; instead, we have worked to understand the underlying principles behind what makes the bird wing good for flying and applied these principles to our design. Our work is inspired by nature but does not seek to mimic it.
So, why do we take inspiration from animals rather than imitate them?
Our rationale for bio-inspired design over biomimetic design lies in the premise of biomimicry itself – that living organisms are designed to be well-adapted to their environment. And while this is, in the most part, true, it does not mean that this translates to optimal designs for human engineering requirements. Let’s pull apart this idea a little further.
Designed for what purpose?
The environment is messy and provides a complex and often conflicting set of design requirements; it is not as specific as the human problems we are trying to solve. The primary function of a swallow tail may be for flight – so it is likely to be well-designed for this purpose. However, that does not mean it is exclusively designed for this requirement; the tail is also used to attract females. Two processes here are shaping tail design: natural selection, to be well-adapted for survival; and sexual selection, to be well-adapted for mate attraction. In comparison, our requirements are different and less complex – we want optimal flight efficiency. Therefore, simply imitating the swallow tail will not provide the optimal design for efficient flight. However, if we understand the underlying biology behind the swallow and the biomechanics of how it works, we can take the principles that do make it well-adapted for efficient flight and apply these, and these only, to our engineering brief.
Even within the realms of a single selection pressure in natural selection, this notion of being well-adapted is not congruent with human design purpose. Natural selection is a process by which genes and characteristics are passed on because they make the individual more likely to survive. Survival is often more complex than human design tasks, or, at the least, has different pressures. For example, imagine we are designing a fast swimming vehicle and look to the fins of a particular fish species. Those fins may be a certain size because there is a trade-off between the speed gains by having larger fins and the need to be as inconspicuous as possible to avoid detection by predators. Now in our case, we don’t care about being inconspicuous; so, we should design a vehicle with the optimal fin size for swimming efficiency only – and this isn’t the same as the fins the fish has! If we imitated the fish fin, we would have a sub-optimal design for our purpose.
Animals are not a blank canvas
Additionally, the design may also not be optimal simply because of historical constraints in animal anatomy. For example, the stomach of the octopus passes through its neural centre and it does this not because it is the optimal way to perform neurological functions and digest food at the same time (it almost certainly is not), but because of the historical constraints of its developmental evolution. When we design things, we can start from scratch without historical constraints and so may be able to achieve a more optimal design.
Can we ignore man-made designs?
Finally, we need to be open to the fact that nature may not always have the best solution, as some well-designed man-made engineering solutions are simply not possible for animals to evolve. Planes and cars, for example, rely on the endless rotation of wheels or propellers for movement. This isn’t the design solution seen in nature. That doesn’t, however, make wheels and propellers bad designs; just not possible. Animals require lots of internal wiring (like nerves and blood vessels) to be attached to living parts of their body. Any part that rotates for too long without reversing direction could cause this wiring to become tangled and damaged. If we were purely designing things based on biomimicry, copying nature, we would be forced to abandon these well-adapted solutions. Bio-inspired designs, however, are free to choose concepts from both artificial and natural mechanisms, combining the best of both worlds to create ever more effective and efficient designs.
Written by: Zoe Griffiths and Jonny Page