Returning to Nature…Bio-mimicry Advancements in Engineering

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Conjuring an image of “nature” typically entails lush forests, deep canyons, sunsets over the horizon, or whatever your favorite landscape may be. The commonplace reason for “returning to nature’ has been a reset button for the overstimulated brains of the modern person. Viewed as separate, purer, and even foreign, some of the most fascinating elements of nature often go overlooked by the everyday passerby.

However, the concrete jungle that envelops most of the developed world seems to be creeping closer to its natural roots. Our deep admiration and awe of the non-human world combined with our obsessive drive to innovate is blurring the lines between the landscapes. Some of what we see as the simplest elements of nature are turning into impressive feats of engineering.

As the world refocuses on the Sustainable Development Goals, responsible engineering is at the forefront of what could be considered a metamorphosis. Organizations such as the Biomimicry Institute, Biomimicry 3.8, and a growing cadre of universities are creating nature-inspired solutions to help grow a healthier planet.

Our built environment is held together by a glue of concrete creating a bifurcating web between humanity and the more organic, non-human elements. The scale of concrete use across the planet is immense, with the industry accounting for roughly 7% of global greenhouse gas emissions. New research in materials science is harnessing the power of nature to reinvent concrete at its core. The profound technologies explained below, designed to mimic basic biology, could positively impact industrial sustainability for generations.

One example of such engineering is self-healing concrete. The smallest of cracks can grow the mightiest of oaks, but they can also create an unseen world of destruction, corrosion, and instability. Dilapidated infrastructure remains a pervasive issue, and researchers at Binghamton University and the State University of New York are working to nip this problem in the bud. Inspired by the ability of the human body to heal itself after injury, self-healing concrete uses a fungus called Trichoderma reesei to seal the fractures as they crop up. Fungal spores and nutrients are added to the concrete matrix during mixing and then lies dormant until the cracking first appears. When enough water and oxygen penetrate the split, the fungal spores germinate and grow. Precipitating calcium carbonate as a byproduct of the fungal growth, the cracks fill, cutting off the supply of oxygen and water and mending the break. The fungi again form spores and wait patiently for the next crack to appear. 

Another engineering adaptation adopts lobster inspired patterns in 3D printed concrete. This method of manufacturing has the potential to improve time, effort, and material efficiencies in civil engineering design projects. By biomimicking the spiral patterns in lobster shells, 3D printed concrete enables strength to be directed precisely to areas needing increased structural support. Exoskeletons like the ones fabricated by crustaceans have evolved to harness key advantages in design for stability and performance. Emerging 3D printing technologies greatly enhance engineering productivity and will transform the way our built environment is created from the ground up. This layer-by-layer approach slashes costs, time, and enhances finished engineering projects by utilizing bio-mimicked combinations of printing patterns, material choices, models, and reinforcement options.
 
Our reliance on concrete to stabilize our environment is not without costs, however. Like we mentioned, the carbon emissions from producing 4 billion tons of cement per year will proliferate detriment to the atmosphere. Although extending its life through the self-healing and 3D printed innovations, researchers at Aalto University are trying to move away from concrete use altogether. Developing a bio-based coating for wood may be the answer. Prone to degradation from moisture and sunlight, wood is not always the first choice of building materials. However, researchers have harnessed the innate resiliency of trees in the form of lignin. This abundant wood polymer is often regarded as a waste product in biorefinery and pulp processing. It is estimated that between 60 and 120 million tons of lignin is isolated annually world-wide, and of that, 98% is incinerated. Therefore, the potential applicability of lignin as a coating material is huge. Currently, protective coatings are primarily petroleum-based and included environmentally harmful substances. Outperforming traditional synthetic options, a lignin-based sealant coating is a safe, low-cost, high-performing construction option. Again, nature has provided us with an anti-corrosive, anti-bacterial, anti-icing, UV-shielding, bio-mimicked alternative.
The global urge to meet rising sustainability standards continues to drive material transformations and bio-mimicked alternatives even further. The longevity, persistence, adaptability, common in both nature and humanity, enables us to see, and emulate, the gifts that reside just outside our industrial frame of reference. While basic biology-based innovations provide us with sustainable growth opportunity, they are also the sincerest form of flattery for the vastly beautiful and complex world we are a part of.
 
Citations:
Aalto University. (2021, July 23). Bio-based coating for wood outperforms traditional synthetic options: Researchers turn a non-toxic residue into wood coating that resists abrasion, stain, and sunlight.ScienceDaily.RetrievedSeptember20,2021,from www.sciencedaily.com/releases/2021/07/210723105310.htm
Binghamton University. (2018, January 17). Self-healing fungi concrete could provide sustainable solution to crumbling infrastructure: New concept offers low-cost, pollution-free and sustainable approach to fixing concrete. ScienceDaily. Retrieved September 17, 2021, from www.sciencedaily.com/releases/2018/01/180117152511.htm
RMIT University. (2021, January 19). Bio-inspired: How lobsters can help make stronger 3D printed concrete. ScienceDaily. Retrieved September 17, 2021, from www.sciencedaily.com/releases/2021/01/210119102846.htm