BiomimicryCivil Engineering Applications ...

Introduction

What is biomimicry? • Most of the problems humans face today are

also faced by other organisms. Over the course of evolution, many organisms gained more efficient ways to use their environment.

• The organisms that are alive today are the successful models or products of evolution. We could learn a lot from nature when it comes to solving our challenges in a sustainable way..

Biomimicry

Bio-mimicry• The interdisciplinary field where

technology, science, art, design and architecture influence each other and use biology for innovative solutions and products is called biomimicry.

Biomimicry• Biomimicry can be applied on three levels. • Firstly, the natural form of organisms are used for

inspiration. For instance, mimicking the structure of a seashell could lead to stronger buildings.

• Secondly, natural processes, for example chemical processes such as photosynthesis, can be mimicked to create more sustainable materials.

• The third level is the ecosystem level. In this level, entire ecosystems and their functional principles are mimicked. When a product is made with the help of biomimicry, it is called a 'biomimetic' product. It can be biomimetic in terms of form, material, construction, process or function.

Biomimicry can be applied on three levels.

Creating a Sustainable Design

• Thus, Biomimicry is an approach to innovation that seeks sustainable solutions to human challenges by emulating nature’s time-tested patterns and strategies. The goal is to create products, processes, and policies—new ways of living—that are well-adapted to life on earth over the long haul.

Examples of Biomimicry

Cement having Composition of Corals

• Bio-mineralization expert Brent Constantz of Stanford University was inspired to make a new type of cement for buildings by the way corals build reefs. The process of making this cement actually removes carbon dioxide – a greenhouse gas, thought to cause global warming – from the air.

Brent Constantz, Stanford University

Cement like Corals• The installation takes waste CO2 gas from a local

power plant and dissolves it into seawater to form carbonate, which mixes with calcium in the seawater and creates a solid. It’s how corals form their skeletons, and how Constantz creates cement.

Cement like Corals

Cement like Corals

• There’s a natural interaction between CO2, which is a gas, and water. They come into equilibrium together and the CO2 is dissolved in water. This forms another molecule, CO3, which is called carbonate. The higher the concentration of CO2, the more carbonate is form.

Cement like Corals• Sea water has calcium. When the calcium sees the

carbonate, it forms calcium carbonate, the solid. That is called limestone, That’s how corals form their shells.. The solids that form fall to the bottom and are separated. They’re dried out using the waste heat from the hot flue gas. That produces a powder in a spray dryer, which is akin to a machine making powdered milk. And that is the cement. The cement can be used to make aggregate, synthetic rock like synthetic limestone, or it can be kept dry as a cement and used in a concrete formulation.

Cement like Corals

Cement from CO2: A Concrete Cure for Global Warming?

• Cement from CO2: A Concrete Cure for Global Warming?

Passive cooling in buildings

• The East-gate Complex, located in Harare, Zimbabwe, is a commercial office and shopping complex which includes two nine-storey office buildings and a glazed atrium. In Zimbabwe’s extremely hot climate, the building’s primary cooling method is natural ventilation.

The East-gate Complex, Harare, Zimbabwe

Passive cooling in buildings

• Engineers from firm Arup, led by Mick Pearce, sought inspiration for the ventilation design from termite mounds since termites require their home to remain at an exact temperature of 87°F (30.5°C) throughout a 24-hour daily temperature range of between 35°F at night and 104°F during the day (1.6°C to 40°C). The solution was a passive-cooling structure with specially designed hooded windows, variable thickness walls and light coloured paints to reduce heat absorption.

Passive Cooling in Buildings

Ar. Mick Pearce

Passive cooling in buildings

• Biomimicry’s Cool Alternative• Eastgate Centre in Zimbabwe

The Eastgate Centre in Harare, Zimbabwe, typifies the best of green architecture and ecologically sensitive adaptation. The country’s largest office and shopping complex is an architectural marvel in its use of biomimicry principles.

Passive cooling in buildings

Passive cooling in buildings

• Termites in Zimbabwe build gigantic mounds inside of which they farm a fungus that is their primary food source. The fungus must be kept at exactly 87 degrees F, while the temperatures outside range from 35 degrees F at night to 104 degrees F during the day. The termites achieve this remarkable feat by constantly opening and closing a series of heating and cooling vents throughout the mound over the course of the day.

Passive cooling in buildings

• With a system of carefully adjusted convection currents, air is sucked in at the lower part of the mound, down into enclosures with muddy walls, and up through a channel to the peak of the termite mound. The industrious termites constantly dig new vents and plug up old ones in order to regulate the temperature.

Termite Mounds

Passive cooling in buildings

• The Eastgate Centre, largely made of concrete, has a ventilation system which operates in a similar way. Outside air that is drawn in is either warmed or cooled by the building mass depending on which is hotter, the building concrete or the air. It is then vented into the building’s floors and offices before exiting via chimneys at the top.

Passive cooling in buildings

Passive cooling in buildings• The Eastgate Centre uses less than 10% of the energy of a

conventional building its size. These efficiencies translate directly to the bottom line: Eastgate’s owners have saved $3.5 million alone because of an air-conditioning system that did not have to be implemented. Outside of being eco-efficient and better for the environment, these savings also trickle down to the tenants whose rents are 20 percent lower than those of occupants in the surrounding buildings.

• Who would have guessed that the replication of designs created by termites would not only provide for a sound climate control solution but also be the most cost-effective way for humans to function in an otherwise challenging context?

Passive cooling in buildings

Passive cooling in buildings

Self-cleaning paints

• Germany company, StoColor Lotusan® have developed a biomimicry inspired exterior coating with a water-repellant surface based on that of the lotus leaf.

• Professor Wilhem Barthlott, from the University of Bonn in Germany, developed the surface after looking for environmentally benign alternatives to toxic cleaning detergents in order to reduce environmental impacts.

Prof. Wilhem Barthlott

Self-Cleaning Paints

Self-Cleaning Paints

• He asked the question ‘How does nature clean surfaces?’ It became obvious that nature doesn’t use detergents at all – instead it designs self-cleaning surfaces with hydrophobic properties.

Lotus Effect

• Do you know lotus effect? • The lotus is an Asiatic aquatic plant known

for the super-hydrophobic behaviour of its leaves. What does super-hydrophobic mean? It means that the leaves do not get wet as they repel water.

Lotus Effect

Lotus Effect

• When the rain droplets touch the lotus leaves they remain spherical which allows the droplets to bounce around until they fall off the leaf which stays dried.

• This phenomenon carries out other advantages as when droplets run through the surface they pick up the dust that accumulates on top, leaving the leaves completely cleaned as well as dried. This self-cleaning effect is called lotus effect alluding to this wonderful plant but it can be also found in other plant species, birds and even insects.

Lotus Effect

Lotus Effect

• This phenomenon has aroused great interest for its numerous potential applications in self-cleaning materials and in many different fields.

Lotus Effect

• If we take a look at the lotus leaves under the microscope we will see a very distinctive surface, built up in 2 levels: tiny bumps can be seen in a microscopic scale, and on its tips a second level is formed by thin nano-metric wires. Furthermore, this structure is covered with a waxy layer that increases the hydrophobic effect. This doble structure underpins water dropplets that maintain their spherical shape and the waxy layer favours the rolling of the droplets without wetting the leaf surface. Therefore, is the combination of the physical and chemical effects what allows to affirm that lotus leaves are super-hydrophobic.

Lotus Effect

Leaves of the sacred lotus are self-cleaning thanks to hydrophobic microscale bumps.

• Lotus plants (Nelumbo nucifera) stay dirt-free, an obvious advantage for an aquatic plant living in typically muddy habitats, and they do so without using detergent or expending energy.

Eco-Friendly House Paint Inspired By The Self-Cleaning Lotus Flower

• This phenomena has been named the ‘Lotus Effect’ and, not surprisingly, it has inspired an entire industry of self-cleaning textiles, windows, sprays and other products. One of the more interesting is an eco-friendly house paint called Lotusan. Developed by a German company called ISPO, this exterior paint employs a microstructure modeled after the hydrophobic leaves of the lotus plant to minimize the contact area for water and dirt.

Lotusan Biomimicry Paint

• Using the same physical technology that lotus flowers use to keep dry and clean while growing out of murky water, the paint adds a texture to the surface of a material which causes water to form into droplets and bead off, taking dirt and bacteria with it.

Lotusan Biomimicry Paint

Lotusan Biomimicry Paint

• The paint creates microstructures on the façade of buildings in a way that is similar to the microstructures on lotus leaves In addition to, keeping the buildings cleaner, Lotusan also reduces the build-up of algae and mold. As a result, maintenance costs are lower and façades have to be repainted less frequently.

• To give an impression of how effective the hydrophobic effect is: When you stick a spoon with a Lotus leaf-like surface into a jar of honey, it will come out clean, without any stickiness. However, functionality is not the only important factor in the view of sustainability. Chemical composition and durability are other factors to keep in mind.

Lotusan Biomimicry Paint

Self-Healing buildings

• Concrete is the most widely used building material and is found in almost every building. More than one m3 of concrete is produced per person on earth every year. However, the production of concrete has a serious environmental impact.

• The cement production, which is the primary component of concrete, contributes more than 5% to the by human generated greenhouse gas emissions. Producing one ton of concrete leads to the emission of 100 kg of CO2. Another problem with concrete is that it is prone to cracking, which reduces the lifespan of concrete buildings. Maintaining concrete buildings is therefore quite expensive.

Self-Healing buildings

• Henk Jonkers is a Dutch microbiologist who, together with the Tu Delft, developed concrete that fills the cracks that appear over time Specialized microorganisms that are added cause this self-healing ability. Strictly speaking, using bacteria in the concrete makes this product bio-assisted instead of biomimetic.

Henk Jonkers, Microbiologist

Self-Healing Buildings

Self-Healing Buildings• In nature, bacteria exist that can not only survive in the arid

conditions of concrete, but also produce limestone. These bacteria can be incorporated, together with nutrient-containing clay capsules, into the concrete. Alkaliphilic bacteria of the Bacillus genus are especially suitable for this application. When the concrete is undamaged the bacteria are in a dormant state. In the dormant state, the bacteria form endospores which can survive for several decades without water and nutrients. When a crack occurs, water can infiltrate the concrete. Contact with water reactivates the endospores, causing the bacteria to grow and form calcite, by oxidation of calcium lactate. Calcite is a major component of limestone. The produced calcite fills the crack and repairs the damage.

Self-Healing Buildings

Self-Healing Buildings

Self-Healing Buildings

Self-Healing Buildings

Harvesting Fresh Water

• In dry areas such as deserts, fresh water is scarce and needs to be transported from other areas. What if we could design buildings in deserts that can generate their own fresh water supply?

• The Namib Desert beetle is a source of inspiration for achieving this goal.

Namib Desert Beetle

Harvesting Fresh Water

• Namibia is a country located in South-West Africa. Along its coastline lies the Namib Desert, which is mostly uninhabited by humans because it is so arid. Still, there are organisms that can live there, and amongst them are a few species of the family Tenebrionidae, also known as Darkling beetles.

• These beetles can survive because they collect water from the fog that comes from the ocean and spreads into the desert. This behaviour is called fog basking Fog events only take place about 30 days per year, but the yield of water is sufficient for most desert organisms to survive.

Fog Basking

Harvesting Fresh Water

• When a fog event occurs, the beetles Onymacris unguicularis and O. bicolor stand on their head with their back facing the wind. Little droplets of water from the fog collect on their elytra; hardened front wings which serve as a protective wing case. Bigger droplets are formed, which roll down the back of the beetle and into its mouth.

Namib Desert Beetle

Namib Desert Beetle

Harvesting Fresh Water

• Fog-basking behaviour, rather than the structure of the elytra, has inspired several architects to design buildings that are able to collect fog in arid regions. For example, the Seawater Greenhouse in Oman uses the evaporation of seawater to create fresh water.

• The seawater is pumped from the sea to the porous cardboard evaporators at the front of the greenhouse through pipes. There it evaporates, which causes the air inside to cool down and humidify.

Seawater Greenhouse in Oman

Seawater Greenhouse in Oman

Harvesting Fresh Water• This in turn reduces the transpiration rate in the

plants, resulting in a lowered need for irrigation. When water evaporates, the salt is left behind in the evaporators, leaving the water desalinated. In the roof of the building, seawater running through black pipes is heated by the sun, which causes the surrounding air to be hot and saturated. When the hot air passes through pipes with cool seawater, water starts to condensate on the pipes.

Harvesting Fresh Water

Harvesting Fresh Water

• This fresh water can be collected and stored in a tank. Not only the inside of the greenhouse profits from this system, but the area outside it becomes green as well. The water that escapes the greenhouse forms fog and rain, causing plants to grow in the previously dried out soil Imagine that this technique could transform dry areas, in which no agriculture was previously possible without enormous costs of energy and water, into green, food- and water-producing settlements.

Harvesting Fresh Water

Harvesting Fresh Water• Not only agriculture could benefit from this

technique, but a wide range of buildings could be designed to desalinate seawater and provide a more sustainable source of fresh water for arid urban areas. In the Canary Islands, a start was made with the Las Palmas Water Theatre, designed by architect Nick Grimshaw Although it has not yet been built, the design has gained a lot of attention, because it is not only an eye-catching building, but it could also supply a large part of the city of Las Palmas with fresh water.

Las Palmas Water Theatre

Las Palmas Water Theatre

References• Architect Mick Pearcehttp://www.mickpearce.com/• Biomimicry Institute, Missoula, Montana ,USAhttps://biomimicry.org/what-is-biomimicry/• Brent Constantz - Associate Professor of Geological and Environmental Sciences https://

biox.stanford.edu/about/people/affiliated-faculty/brent-constantz-consulting-associate-professor-geological-and

• Las Palmas Water Theatrehttp://www.exploration-architecture.com/projects/las-palmas• Researcher Henk Jonkers from TU Delft Uniiversity http://www.tudelft.nl/en/current/latest-news/article/detail/zelfherstellend-biobeton-tu-delft-genomineerd-voor-european-inventor-award/• Seawater Greenhouse in Oman http://www.seawatergreenhouse.com/oman.html• Urban Biology,http://www.projects.science.uu.nl/urbanbiology/articlepagebiomim.html• Professor Wilhem Barthlotthttp://lotus-salvinia.de/index.php/en/12-kategorie-deutsch/kontakt-ueber-uns/psite/11-prof-wilhelm-barthlott

There no better design than nature…

Thanks…