June 3, 2021
Biomimicry imitates the models, systems, and elements of nature in order to solve complex human problems. Merging biomimicry and construction together results in the term biomimetic construction — the use of natural models to create new structures and technologies.
Self-healing concrete leads the list of biomimetic technology in construction. Water seepage in concrete causes cracks to widen. Water can initiate structural damage to a building’s foundation.
What if water seepage healed concrete? Bacteria-based self-healing concrete regenerates when cracks appear. Builders mix bacterial spores (Bacillus pseudofirmus) in water-permeable capsules with conventional concrete to strengthen the overall product. These inert capsules do not affect the strength of the concrete until water touches them (usually in the form of water seeping into cracks). The spores react, becoming a kind of “biocement” and fill the cracks in the concrete. A high price tag prevents self-healing concrete from hitting the general market. But this innovation could offer a glimpse of the future of biomimetics in construction.
The lotus flower, another example of biomimetics, seems impervious to water and dirt. Botanists used high-powered telescopes to discover that the floating plants consist of tiny folds that reduce surface contact and repel contaminants. The US Naval Research Office investigated the “lotus effect” with the intent to incorporate its contaminate-repellant properties into surfaces, paints, textiles, and tiles.
Sharkskin inspires biomimetics. For decades, the US Naval Research Office sought a way to stop algae from gathering around docks and piers. Sharkskin offers a solution. The skin, arranged in diamond-shaped denticles, stops microorganisms from grabbing hold. This diamond-shaped barrier doesn’t injure the microorganisms; it prevents them from adhering to the surface. So engineers developed Sharklet, a material with shark skin properties, but scaled down to 3 microns high and 2 microns wide.
Neri Oxman, professor at MIT and coordinator of the Mediated Matter Group, says: “Since the industrial revolution, the world of design has been dominated by the rigor of manufacturing and mass production. Assembly lines dictated a world made of parts, framing the imagination of designers and architects who were trained to think about their objects as a result of parts with different functions.”
Biomimetics inspires exciting theories. “This means of production contrasts the natural processes, where similar cells transform and adapt to perform different functions, and structures are optimized for a multiplicity of functions at various scales: structural load, environmental pressures, spatial restrictions, and so on. Instead of assembling parts, natural structures grow. Could our materials be like that too?”
Biomimetics could mean groundbreaking changes to architecture and construction. However, two questions remain: will the technological theories live up to the hype? Second, can researchers make biomimetics cost-effective at scale?