Against Biomimicry

The thesis of Cats Paws and Catapults is an argument against naive biomimicry. There is a fashionable and romantic belief that natural design is “better” than manmade technology, and human technologists should therefore borrow designs from nature.
The clearest counterarguments Steven Vogel brings are about locomotion by air and water. The attempt to use birds as a model for human flight set inventors off in the wrong direction. Birds are smaller than people, and so the characteristics of their flight technology is different. Larger entities need to go faster to stay aloft. Propellers and jets are superior to flapping wings for heavy humans; lighter birds don’t need the speed. Similarly, marine creatures are smaller than ships. Waves pose a significant barrier for smaller, lighter swimmers, so most marine locomotion happens beneath the surface of the water. Characteristics change yet again at smaller sizes; some insects like water striders are just the right size to take advantage of surface tension.
“Cat’s Paws” compares and contrasts human technology with natural technology in a range of domains: structure, shape, materials, locomotion, using lots of examples from the worlds of biology and artifact. Vogel explains the physical principles, benefits and tradeoffs for the different design approaches, using words to describe the basic math. The material would be even more fun and memorable with animated calculators that showed the changing properties of flight, structural support, and so on, allowing participants to see the impact of changing values. I wonder if this simulation exists somewhere.
The argument is made with a light hand, and the bulk of the book consists of delightful comparisons and contrasts between very different ways of solving design problems. When it comes to biomimicry, Vogel argues the most effective examples involve borrowing some aspects of a natural design, such as a dolphin’s streamlined shape inspiring aerodynamic vehicles, a beetle’s jaws inspiring chainsaw teeth, and the adhesive characteristics of burr inspiring velcro. The models are adapted from nature to the specific design problem and materials needed for the human requirement.
The critique of naive biomimicry focuses largely on the operating characteristics of the technologies: how they solve the presenting design problems of structure and motion. In doing so, Vogel misses a few key points about how and why human designers might want to emulate nature.
Vogel explains that human technology is able to leverage much higher temperatures and temperature ranges than natural technologies. The book, published in 1997, takes for granted the enormous amounts of seemingly cheap fossil fuel energy that allows humans to run our blast furnaces and jet engines. Sample throwaway quote: “One must remember that, their image makers notwithstanding, utility companies are in the business to sell, not save power.” (California fixed this in 1982, when the state Public Utilities Commission came up with the decoupling idea that would allow utility profits to grow while sales declined.)
Another topic that the book doesn’t address at all is waste. Human production processes have tended to create vast quantities of frequently harmful waste; smog, nonbiodegradable plastics, heavy metals in rivers, fertilizer-created dead zones in oceans. Natural processes tend to consume byproducts instead of creating waste, perhaps because they evolved at slower scale in the context of ecosystems, and perhaps because of accidents of chemistry. Birds digest fruit pulp and excrete the seeds that grow another plant. Animals at the end of their life become food for vultures, larvae, and bacteria.
To date, human industrial technologies have been hugely wasteful of energy and materials. Our culture needs more sustainable processes, not because it sounds romantic but because the current solutions won’t last. Vogel’s insight that natural models are best adapted, not borrowed, can be seen in industrial parks that use the byproducts of one manufacturing process as the feedstocks for another, and the use of microbes to detoxify industrial waste.
There are other areas where science and technology have gone beyond the information available to Vogel when he wrote the book a decade ago. Human artifacts are assembled or processed, while natural artifacts are grown. The growth process consists of an development process that creates the organism, and the ongoing chemical processes that sustain the organism; both sets of processes governed by genetic programs. Human products are often assembled at the macroscopic level, while biological products are assembled at the molecular and cellular levels. It would be interesting now, and probably even more interesting ten or twenty years from now, to read a version of the book taking into account insights and progress in the areas of gene-driven development and nanotechnology.

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