By Gabriela Palma
Have you ever wondered how Velcro came to be? George de Mestral was on a hike when he noticed burrs sticking to his clothes. Upon closer examination, he observed that the burrs’ surfaces were made of tiny hooks that clung to the loops of thread on his clothes. Mestral realised he could pull them off and reattach them easily, so he mimicked the hook and loop structure of the burrs to create Velcro. This is an excellent example of biomimicry coming into play.
What is biomimicry?
Biomimicry is a process of designing systems and materials modeled after biological processes that have been optimized by natural selection. By observing these natural processes, we can emulate how nature solves common problems and adapt those strategies to fit human needs.
Over the course of 3.8 billion years, nature continues to evolve and perfect its complex systems and organisms. As a result, it is an expert in efficiency and resilience. Biomimicry explores how to harness the genius of nature to guide human endeavors and problem solving. It pushes past the boundaries of traditional thinking to radically change the way we find restorative solutions to present and future challenges.
Below are a few case studies of how biomimetic design has influenced the built environment.
Biomimicry in the Built Environment
Source: Ask Nature
One simple but versatile example of biomimicry is found in emulating lotus leaves to create water and dirtproof materials. Lotus leaves have hydrophobic microscale bumps—made of epicuticular wax that is found on the surface of many plants—that give it a roughened surface. This prevents water from adhering to its surface, promoting the cohesion necessary to form large water droplets. As gravity forces the droplets to roll off the leaf, they collect dust and other particles, thereby cleaning the surface of the plant.
The fascinating waterproof and self-cleaning properties of the lotus leaf has led to the design of textured surfaces like glass, paints and plastics. These materials can be employed to eliminate water and chemicals needed for cleaning building fabrics, make roads safer in wet weather and reduce wind resistance on windshields to create more fuel-efficient vehicles.
Source: CalTech John Dabiri
John Dabiri, a researcher at Caltech, studied the movement of schools of fish to create more compact and efficient wind turbines. He found that as the fish swam, the energy expelled by the fish in front reduced the drag for the fish behind them. The opposing forces created by fin movements (illustrated in blue and red in the graphic above) significantly reduced energy required by the school for swimming.
Dabiri’s wind turbines have a vertical axis so that, like the school of fish, they can capture wind energy from every direction—even from other turbines. Units facing opposite directions are strategically placed next to each other so that their opposing wind currents lower the drag on the turbines, thereby maximising their efficiency. These units are ten metres tall and can be placed roughly five metres apart, while standard wind turbines require twenty diameters in spacing. For the largest wind turbines currently in use, this distance can reach more than one mile.
Source: National Geographic
Architect Mick Pearce emulated the self-cooling properties of termite mounds to design Zimbabwe’s largest office and retail building, Eastgate Centre. [GP1] This building does not have traditional heating or cooling systems but uses a series of air tunnels to naturally regulate its temperature year-round.
Pearce used brick and concrete for the construction of the building. Like the soil in termite mounds, these materials have a high thermal mass, meaning that they can absorb a lot of heat with minimal changes to its temperature. Termite mounds are also porous, allowing air to pass freely through the structure as the surrounding air temperature fluctuates. Low-power fans located at the base of Eastgate Centre pull in cool air at night and disperse it throughout the building, cooling the concrete and circulating air. In the morning, warm air rises and is released through the chimneys.
Eastgate Centre uses less than ten percent of the energy used by other buildings of its size while maintaining internal temperatures of around 28? during the day and 14? at night.
Biomimetic thinking has influenced everything from infrastructure and construction to political systems and social networks. These examples demonstrate but a fraction of the versatility of biomimicry and its capacity for stimulating creative strategy and design. They are evidence that, like the natural world, we can continue to evolve our innovative practices to create more efficient and resilient communities.
Managing waste streams is an essential part of this transition. Waste does not exist in nature—the by-products of one species are upcycled to become resources for another. Keep an eye out for another piece in our following newsletters that explores how biomimicry is used as a tool for designing circular economies!