Originally posted Monday, 26 March 2012

Written by Katharine Curcio

A burgeoning movement in the world of sustainable design is all about deriving innovation from the very medium sustainable design aims to preserve—nature itself. Considered one way, our biosphere is a 3.8-billion-year (and running) research and development program for solving problems presented by the natural world. Biomimicry—an interdisciplinary movement aimed at putting nature’s solutions to work for human needs—has been around as a concept for some time; the Wright brothers, after all, drew inspiration for the design of their first planes from observations of the flight of pigeons. The term “biomimicry,” though, was popularized by scientist and author Janine Benyus in her 1997 book, Biomimicry: Innovation Inspired by Nature. Benyus later went on to found the Biomimicry Institute, a not-for-profit organization that promotes the study and imitation of nature’s designs, bringing together scientists, engineers, architects, and innovators who can use those models to create sustainable technologies.

Biomimicry is about more than imitating the appearance of natural organisms. It strives to understand how nature functions and how that functionality can translate into innovation in architecture, construction, the sciences—almost any field. Biomimetic solutions have already been applied in many fields—from medicine to agriculture to power generation— and are providing more efficient and environmentally conscious solutions to problems affecting endeavors of all sorts. One of the most promising areas for the solutions biomimicry has to offer is in the built environment—from design to materials sciences and everything in between.

Zimbabwe’s Eastgate Centre is the largest office and retail center in the country, and it draws significant inspiration from termite mounds, a ubiquitous sight in Sub- Saharan Africa. Eastgate Centre has no air conditioning or heating, but instead uses the methods developed by termites to maintain a constant temperature within their nests. Termite colonies cultivate a fungus inside their nests as a food source, and this fungus flourishes only when kept at exactly 87 degrees Fahrenheit. With the weather in Zimbabwe fluctuating from the 30s at night to the 100s by day, the termites had to devise a way to precisely maintain the temperature of their nests. They rely on a complex array of vents, which the termites open and close throughout the day in order to trap or release heat. The Venturi Effect causes fresh air to be taken in through the bottom and channeled out through the mound’s peak. The temperature within the nest can vary only a single degree, and the termites constantly attend to this system of tunnels and vents in order to keep the temperature in this narrow range.

In the Eastgate Centre, air is taken in at the base of the building by fans and drawn through corridors where it is cooled by the thermal mass of the structure’s concrete. The air then moves into the building via a series of ducts. As cool, fresh air enters the bottom of the building, stale, hot air rises until it eventually escapes through one of the many vents that line the top of the building. While the cooling system in the Eastgate Centre is not a matter of life and death, as in the case of the termites, it does affect electric bills, construction costs, and rent for those in the building. The building uses less than 10 percent the energy other buildings its size with conventional air conditioning systems generally consume. The building Owners saved $3.5 million on installation and operating costs of an air conditioning system, and these savings translated into lower rent for the building’s tenants. Needless to say, the economic efficiency of this cooling method corresponds with the environmental efficiency it offers, with a significantly lower strain on the environment and limited natural resources.

A design for the new Ministry of Municipal and Agricultural Affairs (MMAA) building in Doha, Qatar, also takes a biomimetic approach to regulating its temperature, drawing inspiration from the cactus and how it survives in the harsh desert climate. Qatar receives an average annual precipitation of 3.2 inches. To cope with this environment, the stomata of the cactus—the “pores” through which the plant performs transpiration—open only at night, in order to retain water. The building, designed by Bangkok-based Aesthetics Architects, utilizes an array of smart sunshades over its exterior that open or close automatically depending on the intensity of the sun to maintain comfortable interior temperatures.

A similar solution is inspired by pine cones, which open when they are dry and close when wet in order to release seeds only when conditions are favorable and the air is driest. By adapting the material of the pinecone that allows for this movement, researchers have created vents for a cooling system that change their curvature depending on the humidity of the air inside the building. When there is a buildup of moist air in the structure, sensors inside the system make the vent curve open and allow the moist air to exit, and when the air inside the structure is dry, the vent curves closed and prevents moist air outside from entering the building. Though it currently requires mechanical elements, this system can, in theory, be made to operate without any additional outside power, with the material itself being responsive to changes in humidity, and research is currently underway to make this possible.

A simple solution to greenhouse gas emissions might soon be commercially available as a result of biomimetic inspiration from one of the most important organs, the lung. The human lung is an incredible organ that filters mass quantities of CO2 out of our systems every day. Some specific features of the lung allow for its high efficiency. The thin membrane of the lung allows carbon dioxide to travel through it quickly. The lung has an expansive surface area due to a particular type of tissue that is elastic and three-dimensional in texture (meaning more surface area for gas exchange). It also harbors a unique enzyme, carbonic anhydrase, which allows for the rapid removal of CO2 gas from the bloodstream. A research company identified these three qualities and realized the potential for their application on a greater scale. They are currently in the final stages of developing a system that can separate and contain carbon dioxide harvested from the air. The developers tested the technology in a flue stack, and it effectively removed 90 percent of the carbon dioxide from the emissions. Carbonic anhydrase is also found in many different species of mollusks, which use the enzyme to create their shells. Researchers have had success developing technology to harness this enzyme, changing carbon dioxide gas into limestone, which can then be used as a building material. The promise of technologies such as these in the move to combat global warming and counteract the accumulation of greenhouse gases in the atmosphere is tremendous. And with climate change and sea level projections being revised upward, their implementation seems inevitable.

Interior applications of biomimicry promise to deliver more comfortable and healthier environments for working and living, as well. A recent innovation in turbine technology was inspired by the flippers of a humpback whale. Despite its massive size, the humpback whale can perform extremely precise maneuvers, due to a series of bumps and ridges, called tubercles, which increase the whale’s hydrodynamics. This unique flipper shape inspired research into applying it to fan blade design for increased efficiency in cooling systems and turbines. Fans using these whale-inspired blades make less than one-fifth the noise conventional blades make and use 20 percent less power. A five-bladed, whale-inspired fan does the work equivalent to that of ten conventional blades. These efficiency implications also apply to wind power, where such blades could deliver higher yielding turbines and more electricity.

Biomimicry has also yielded innovation on the materials level. For instance, the leaf of a lotus plant is super-hydrophobic, due to its surface structure, which consists of two layers. The first is the epidermis of the plant, which is covered in tiny papillae—microscopic bumps no larger than 20 microns—and the second is the hydrophobic wax coating. Water droplets bead up because of the coating and roll off the plant on top of the papillae, which allow the water to stay in the mobile droplet form. As a result, the plant is self-cleaning, as dirt particles are more attracted to the water droplets than to the wax coating of the plant and simply roll off with the water. This structure inspired an exterior paint that mimics the structure of the papillae, as well as the hydrophobic properties of the covering wax. It works in the same way the lotus leaves do, and, as a result, buildings stay cleaner for longer without maintenance. Also, because of the lack of moisture or dirt on the walls, fungal growth and algae have difficulty thriving. This self-cleaning property has also been adapted for roofing tiles. Traditional designs for both paint and roofing tiles try to eliminate crevices, instead making the surfaces as smooth as possible. The lotus-inspired approach is, therefore, counterintuitive but significantly more effective in practice. As evidenced both by this self-cleaning surface technology and by the rough edges of the whale-inspired fan blades, biomimetic designs often offer solutions that contradict conventional design assumptions.

Inspiration can be found in the most fundamental characteristics of nature, apart from any particular element. For instance, our biosphere is a closed-loop, homeostatic system in which balance is maintained through the collective actions of all the individual elements (consider that all the biological processes on Earth, taken together, produce no net waste). It is this quality that inspires one consulting company, which aims to eliminate waste completely and integrate this cyclical model into all aspects of design. They help companies create products that are not merely “recyclable,” which is a word often applied to materials that are reusable but with a loss in quality, but products that can be fully reused at a high quality. This can be in the form of a literal nutrient, such as compost that can be used to fertilize a crop, or the worms that the compost attracts being used to feed fish. The nutrient can also be a technological “nutrient,” which facilitates the creation of something else with the same materials but without the waste created by conventional recycling methods.

The principles of biomimicry can be applied to all aspects of the built environment—from materials sciences to power generation. Nature’s designs, when taken as inspiration for a project, can produce great innovations that offer creative solutions to some of the more difficult sustainability problems. Many challenges faced today have already been solved, in some form or another, by nature. The trick of successful biomimetic designs is not to take literal adaptations of naturally occurring phenomena, but to take the essence and the functionality of the natural world and translate it into something useful and innovative for humans.

A burgeoning movement in the world of sustainable design is all about deriving innovation from the very medium sustainable design aims to preserve—nature itself. Considered one way, our biosphere is a 3.8-billion-year (and running) research and development program for solving problems presented by the natural world. Biomimicry—an interdisciplinary movement aimed at putting nature’s solutions to work for human needs—has been around as a concept for some time; the Wright brothers, after all, drew inspiration for the design of their first planes from observations of the flight of pigeons. The term “biomimicry,” though, was popularized by scientist and author Janine Benyus in her 1997 book, Biomimicry: Innovation Inspired by Nature. Benyus later went on to found the Biomimicry Institute, a not-for-profit organization that promotes the study and imitation of nature’s designs, bringing together scientists, engineers, architects, and innovators who can use those models to create sustainable technologies.

Biomimicry is about more than imitating the appearance of natural organisms. It strives to understand how nature functions and how that functionality can translate into innovation in architecture, construction, the sciences—almost any field. Biomimetic solutions have already been applied in many fields—from medicine to agriculture to power generation— and are providing more efficient and environmentally conscious solutions to problems affecting endeavors of all sorts. One of the most promising areas for the solutions biomimicry has to offer is in the built environment—from design to materials sciences and everything in between.

Zimbabwe’s Eastgate Centre is the largest office and retail center in the country, and it draws significant inspiration from termite mounds, a ubiquitous sight in Sub- Saharan Africa. Eastgate Centre has no air conditioning or heating, but instead uses the methods developed by termites to maintain a constant temperature within their nests. Termite colonies cultivate a fungus inside their nests as a food source, and this fungus flourishes only when kept at exactly 87 degrees Fahrenheit. With the weather in Zimbabwe fluctuating from the 30s at night to the 100s by day, the termites had to devise a way to precisely maintain the temperature of their nests. They rely on a complex array of vents, which the termites open and close throughout the day in order to trap or release heat. The Venturi Effect causes fresh air to be taken in through the bottom and channeled out through the mound’s peak. The temperature within the nest can vary only a single degree, and the termites constantly attend to this system of tunnels and vents in order to keep the temperature in this narrow range.

In the Eastgate Centre, air is taken in at the base of the building by fans and drawn through corridors where it is cooled by the thermal mass of the structure’s concrete. The air then moves into the building via a series of ducts. As cool, fresh air enters the bottom of the building, stale, hot air rises until it eventually escapes through one of the many vents that line the top of the building. While the cooling system in the Eastgate Centre is not a matter of life and death, as in the case of the termites, it does affect electric bills, construction costs, and rent for those in the building. The building uses less than 10 percent the energy other buildings its size with conventional air conditioning systems generally consume. The building Owners saved $3.5 million on installation and operating costs of an air conditioning system, and these savings translated into lower rent for the building’s tenants. Needless to say, the economic efficiency of this cooling method corresponds with the environmental efficiency it offers, with a significantly lower strain on the environment and limited natural resources.

A design for the new Ministry of Municipal and Agricultural Affairs (MMAA) building in Doha, Qatar, also takes a biomimetic approach to regulating its temperature, drawing inspiration from the cactus and how it survives in the harsh desert climate. Qatar receives an average annual precipitation of 3.2 inches. To cope with this environment, the stomata of the cactus—the “pores” through which the plant performs transpiration—open only at night, in order to retain water. The building, designed by Bangkok-based Aesthetics Architects, utilizes an array of smart sunshades over its exterior that open or close automatically depending on the intensity of the sun to maintain comfortable interior temperatures.

A similar solution is inspired by pine cones, which open when they are dry and close when wet in order to release seeds only when conditions are favorable and the air is driest. By adapting the material of the pinecone that allows for this movement, researchers have created vents for a cooling system that change their curvature depending on the humidity of the air inside the building. When there is a buildup of moist air in the structure, sensors inside the system make the vent curve open and allow the moist air to exit, and when the air inside the structure is dry, the vent curves closed and prevents moist air outside from entering the building. Though it currently requires mechanical elements, this system can, in theory, be made to operate without any additional outside power, with the material itself being responsive to changes in humidity, and research is currently underway to make this possible.

A simple solution to greenhouse gas emissions might soon be commercially available as a result of biomimetic inspiration from one of the most important organs, the lung. The human lung is an incredible organ that filters mass quantities of CO2 out of our systems every day. Some specific features of the lung allow for its high efficiency. The thin membrane of the lung allows carbon dioxide to travel through it quickly. The lung has an expansive surface area due to a particular type of tissue that is elastic and three-dimensional in texture (meaning more surface area for gas exchange). It also harbors a unique enzyme, carbonic anhydrase, which allows for the rapid removal of CO2 gas from the bloodstream. A research company identified these three qualities and realized the potential for their application on a greater scale. They are currently in the final stages of developing a system that can separate and contain carbon dioxide harvested from the air. The developers tested the technology in a flue stack, and it effectively removed 90 percent of the carbon dioxide from the emissions. Carbonic anhydrase is also found in many different species of mollusks, which use the enzyme to create their shells. Researchers have had success developing technology to harness this enzyme, changing carbon dioxide gas into limestone, which can then be used as a building material. The promise of technologies such as these in the move to combat global warming and counteract the accumulation of greenhouse gases in the atmosphere is tremendous. And with climate change and sea level projections being revised upward, their implementation seems inevitable.

Interior applications of biomimicry promise to deliver more comfortable and healthier environments for working and living, as well. A recent innovation in turbine technology was inspired by the flippers of a humpback whale. Despite its massive size, the humpback whale can perform extremely precise maneuvers, due to a series of bumps and ridges, called tubercles, which increase the whale’s hydrodynamics. This unique flipper shape inspired research into applying it to fan blade design for increased efficiency in cooling systems and turbines. Fans using these whale-inspired blades make less than one-fifth the noise conventional blades make and use 20 percent less power. A five-bladed, whale-inspired fan does the work equivalent to that of ten conventional blades. These efficiency implications also apply to wind power, where such blades could deliver higher yielding turbines and more electricity.

Biomimicry has also yielded innovation on the materials level. For instance, the leaf of a lotus plant is super-hydrophobic, due to its surface structure, which consists of two layers. The first is the epidermis of the plant, which is covered in tiny papillae—microscopic bumps no larger than 207_DrawingFromNature_eAST-Revised microns—and the second is the hydrophobic wax coating. Water droplets bead up because of the coating and roll off the plant on top of the papillae, which allow the water to stay in the mobile droplet form. As a result, the plant is self-cleaning, as dirt particles are more attracted to the water droplets than to the wax coating of the plant and simply roll off with the water. This structure inspired an exterior paint that mimics the structure of the papillae, as well as the hydrophobic properties of the covering wax. It works in the same way the lotus leaves do, and, as a result, buildings stay cleaner for longer without maintenance. Also, because of the lack of moisture or dirt on the walls, fungal growth and algae have difficulty thriving. This self-cleaning property has also been adapted for roofing tiles. Traditional designs for both paint and roofing tiles try to eliminate crevices, instead making the surfaces as smooth as possible. The lotus-inspired approach is, therefore, counterintuitive but significantly more effective in practice. As evidenced both by this self-cleaning surface technology and by the rough edges of the whale-inspired fan blades, biomimetic designs often offer solutions that contradict conventional design assumptions.

Inspiration can be found in the most fundamental characteristics of nature, apart from any particular element. For instance, our biosphere is a closed-loop, homeostatic system in which balance is maintained through the collective actions of all the individual elements (consider that all the biological processes on Earth, taken together, produce no net waste). It is this quality that inspires one consulting company, which aims to eliminate waste completely and integrate this cyclical model into all aspects of design. They help companies create products that are not merely “recyclable,” which is a word often applied to materials that are reusable but with a loss in quality, but products that can be fully reused at a high quality. This can be in the form of a literal nutrient, such as compost that can be used to fertilize a crop, or the worms that the compost attracts being used to feed fish. The nutrient can also be a technological “nutrient,” which facilitates the creation of something else with the same materials but without the waste created by conventional recycling methods.

The principles of biomimicry can be applied to all aspects of the built environment—from materials sciences to power generation. Nature’s designs, when taken as inspiration for a project, can produce great innovations that offer creative solutions to some of the more difficult sustainability problems. Many challenges faced today have already been solved, in some form or another, by nature. The trick of successful biomimetic designs is not to take literal adaptations of naturally occurring phenomena, but to take the essence and the functionality of the natural world and translate it into something useful and innovative for humans.