Due to advances in computation and nanotechnology, biological knowledge is doubling every five years (Rifkin 1999). Looking forward, what’s the impact on biomimicry? According to Gebeshuber, Gruber, and Drack, biomimicry practitioners increase their chances of success when they focus on emulating biological systems where causation is well-understood (2009); so, as we learn more about biological systems, our ability to develop effective biomimetic technologies grows. Right now the fields of biology where causation is best understood are biochemistry, biophysics, biomechanics, and physiology (as indicated by the ratio of explanatory versus descriptive knowledge) (Gebeshuber, Gruber, and Drack 2009).
What about in hindsight? Looking back, how does exponential growth in biological knowledge impact biomimicry? Often, new scientific discoveries lead to modifications of old theories and occasionally the development of entirely new theories. This means that in some cases scientific theory upon which a biomimetic product or process is based will be revised. For example, Eastgate Centre, a shopping center and office block in Harare, Zimbabwe, was modeled after a termite mound to achieve passive ventilation. When architect Mick Pearce designed Eastgate in 1993, he based his design on a natural convection model of gas and heat exchange in termite mounds (Lüscher 1961). In this model, the termite colony’s metabolic heat warms the air in the underground nest. Hot air buoys upwards from the nest through the mound’s aboveground, central tunnels, and as it loses heat, sinks back down through passages that run parallel to and just below the mound’s surface. During downward passage, the air’s oxygen levels are refreshed via diffusion through the mound’s porous walls (Lüscher 1961). Since Eastgate’s construction, scientists have learned that while heat’s buoyancy effect contributes to gas and heat exchange in some termite mounds, it is only a part of a much more complicated story. Wind also plays a big role. Wind contacting the windward side of the aboveground termite mound drives oxygen-rich air through its porous exterior into the mound’s tunnels. Stale, carbon-dioxide-rich air is sucked out the leeward side (Turner 2001). Eastgate’s architect was not privy to this information, but we are now. What should we do with this new knowledge?
In cases where transfer of a functional principle from biology to design falls short, we should ask ourselves: how did that affect the design’s overall performance? Eastgate’s architect may have had incomplete information, but his design still functions very well. The building’s interior temperature stays in a comfortable range of a few degrees year round. It is much more energy efficient than buildings of similar size with traditional HVAC systems. That said, there may still be room for improvement. When new scientific knowledge becomes available, we should ask: how can we use it to help us improve upon old biomimetic design concepts? Eastgate’s architect did just that, integrating new learnings about termites in a second project, Council House 2 in Melbourne, Australia.
- Gebeshuber, I. C., Gruber, P., and Drack, M., 2009, “A gaze into the crystal ball: biomimetics in the year 2059,” Proc. Inst. Mech. Eng. Part C J. Mech. Eng. Sci., 223(12), pp. 2899–2918.
- Lüscher, M., 1961, “Air-Conditioned Termite Nests,” Sci. Am., 205(1), pp. 138–145.
- Rifkin, J., 1999, The biotech century: harnessing the gene and remaking the world, Jeremy P. Tarcher/Putnam, New York.
- Turner, J. S., 2001, “On the mound of Macrotermes michaelseni as an organ of respiratory gas exchange,” Physiol. Biochem. Zool. PBZ, 74(6), pp. 798–822.