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Incorporating biomimicry into building design

Eden Project, UK

In the past 20 years there have been number of initiatives across a range of technologies that have demonstrated the potential of biomimicry to significantly improve human designs and challenge conventional thinking. Commercially available products include the StoCoat Lotusan self-cleaning surface coatings and Viridian Renew self-cleaning glass, which mimic the cleaning effect intrinsic to lotus leaves and insect wings.

Architecture has taken inspiration from the natural world from its very beginnings. However, much of the recent focus has been either on aesthetic appeal or applying living elements to buildings, such as with green walls.

Functional biomimicry, however, is the practice that translates characteristics from biological systems to building design. The goal of functional biomimicry is to deeply understand the biological world and then abstract that knowledge –in detail –to the technological domain.

It is critical to developing the role of biomimicry to improve building performance. Several researchers have understood the importance of biological function and have developed design methodologies to grasp opportunities from the natural world and translate them into human technology.

Biomimicry 3.8 Design Lens

Janine Benyus, a pioneer of modern biomimicry, has been researching functional biomimicry for more than 20 years. Her work has had a large influence on the development of biomimicry as a discipline for designers and engineers, particularly in the United States. The inspiration provided by Benyus has led to the creation of Biomimicry 3.8 Institute, an organisation devoted to education, developing biological knowledge and advocating the benefits of biomimicry.

In particular, Biomimicry 3.8 emphasises function and functionally advantageous design as the most important factors in applying biomimicry to design. Biomimicry 3.8 also developed and continues to maintain the online database of natural design solutions, AskNature.org.

The Biomimicry 3.8 design philosophy follows the Biomimicry Design Lens, which consists of three key components:

  • essential elements
  • life’s principles
  • biomimicry thinking

The “essential elements” express the ideals of respect and responsibility for the natural environment and emphasise a deep connection between human society and the natural world. The third element expresses the goal to translate and apply natural functions and strategies to a design, while still being mindful of the overall vision of sustainable human development and coexistence.

“Life’s principles” expresses the overarching strategies that have allowed life to be successful in its evolution and sustained survival on planet Earth:

  • evolve to survive
  • adapt to changing conditions
  • be locally attuned and responsive
  • use life-friendly chemistry
  • be resource efficient (material and energy)
  • integrate development with growth

For designers, the principles are a categorisation for characteristics and strategies that might be applied to a design and also offer a set of benchmarks or criteria to assess its successfulness.

Finally, the Biomimicry Design Lens is a framework for designers to contextualise biomimicry within a design process, guiding the integration of biology into design. Two potential design pathways are identified.

Biomimicry Thinking Design Lens: Challenge to Biology

The “challenge to biology” is a more conventional pathway, where a designer aims to enhance a specific design, or solve a design problem by looking to nature. Alternatively, the “biology to design” pathway identifies a useful characteristic from nature, which is abstracted and translated to a technological context before the exact scope and goal of the design is identified.

Engineering Design Process

Biomimicry Thinking Design Lens: Biology to Design

The Engineering Design Process offers engineers a structured method to design a product to meet a specific design goal and is flexible enough to accommodate a biomimetic approach.

The Engineering Design Process can provide some rigour to biomimetic design by defining:

  • what the design should achieve
  • how that achievement is measured
  • how to compare ideas

In the creative ideas generation phase, designers are challenged to think unconventionally, which facilitates biomimetic inspiration, where designers can seek ideas from natural systems to meet the well-defined design goal.

However, while the Engineering Design Process can be useful, the designer is required to exercise judgement throughout, particularly in relation to the translation phase, constructing suitable performance models and deciding upon a particular design. When translating a design from biology to technology it is critical to retain the physical (or chemical) characteristics as understood by current biological science. If this is not achieved then the functional advantages of biomimicry can be lost.

BioTRIZ

A technically-oriented, systematic approach to biomimicry has been proposed by English researchers Julian Vincent and Darrell Mann. They propose to combine biomimicry with TRIZ, Teoriya Resheniya Izobretatelskikh Zadatch, translated from Russian as a “theory of inventive problem solving”.

TRIZ provides an objective framework to classify and access solutions from alternative disciplines and sciences –including the roughly four billion years of evolutionary “research and development” evident in the natural world.

TRIZ contends that the major functions that contribute to the ongoing success of humankind have already been discovered and implemented to some degree. Ongoing advancement relies upon delivering these engineering functions in ever more sophisticated ways, and TRIZ proposes 40 “principles of invention” that can be manipulated to solve virtually any engineering problem.

The TRIZ algorithm involves expressing the design problem in terms of inherent “contradictions”, or design trade-offs. For example, the wing of an aircraft must be strong enough to withstand the imposed lift and drag forces, but also light enough to minimise the energy (and thus fuel) required to propel the aircraft.

Vincent and colleagues suggest that the engineering contradictions stated in TRIZ can be mirrored using research from biological rather than technological systems. Their resulting BioTRIZ matrix summarises how biology solves contradictory objectives, and offers biological “inventive principles” for designers to resolve these contradictions. The inventive principles and contradictions are categorised into six fields as shown in the table below, with an example from both human technology and the biological world.

A statistical comparison of TRIZ and BioTRIZ found a similarity of only 12 per cent. Hence there are clear opportunities to study the means by which the natural world solves “design” problems and apply that knowledge to human design endeavours.

Example technological and biological functions for each of the six operational fields:

Field

Technological example

Biological example

Substance Incorporating hydrogen into metals increases thermal expansion. Amoebae move on solid surfaces by converting gel into liquid and liquid into gel inside the cell wall to create pseudopodia.
Structure Simple tools such as a swiss army knife rely on their shape and structure. Statoliths (graviperception cells in plants) change their position (sediment) inside columella cells, providing a transduction of kinetic energy into a biochemical signal to indicate the direction of gravity direction.
Energy Internal combustion engines provide efficient means for transportation. Woodpeckers use kinetic energy to increase the force the birds can exert on the wood of a tree.
Space The most energy-conserving shape (arrangement of space) for a house is spherical. Dung beetles roll up balls of dung and then transport them away for consumption.
Time Electric toothbushes reduce brushing time. The metabolic rate of a cell assists thermoregulation to ensure stable body temperature at the macroscopic scale.
Information A thermostat provides feedback information to control an air conditioner. DNA and RNA store and transfer information about cell structure via genes and protein sequences.

Case Study – Pax Scientific

The motto of research company Pax Scientific is “capturing the force of nature”, and it has employed the “challenge to biology” pathway defined by the Biomimicry 3.8 Design Lens. Founded in California in 1997 by ex-West Australian Jay Harman, Pax has studied the flow characteristics of nature in order to design more efficient flow devices, such as fans and pumps.

Many existing water-processing components are composed of straight edges and planar surfaces, with curvature along one axis. Instead, Pax designs are based on flow geometry derived from observations of nature.

Through natural evolution, life has optimised fluid flow to minimise drag and reduce energy consumption. Studying these optimised geometries, Pax was able to distil their experimentation and analysis into what the company terms the “streamlining principle”–a single description of the most efficient flow pattern.

This optimal flow pattern could be derived from the Golden Ratio phi (~1.618) and the logarithmic spiral exemplified throughout the natural world. The nautilus shell is one common example of this shape, and was actually used by Pax during initial reverse engineering efforts. Similar spirals can be found in curled elephant trunks, chameleon tails, ocean surf and the cochlea of human ears.

A nautilus shell exhibiting a logarithmic spiral

One of Pax’s most widespread success stories has been in mechanical mixing products for maintaining drinking water quality. Storage of water in tanks, for any period of time, leads to stagnation. Thermal stratification occurs and the warm upper layer loses its disinfectant capability –creating ideal conditions for bacterial growth.

While mitigation methods do exist – such as adding disinfectant or a mechanical mixer – Pax sought a more robust solution.

Lily Impeller as part of the Pax Water Mixer

Thus Pax Water Technologies was born with the goal to create an efficient mechanical solution that would prevent bacterial growth by maintaining the desired concentration of disinfectant throughout the tank –without the need for additional top up and waste.

Using knowledge from natural systems –in particular how water moves in ring vortices –Pax designed the Lily Impeller, which formed the core component of the Pax Water Mixer.

The new Pax mixer was extremely effective in creating conditions unfavourable for bacterial growth. The mixer works continuously, preventing stagnation and even reducing the quantity of chemical dosing required. When compared to traditional mixers, there is a massive reduction in impeller size, dramatically improving energy efficiency. The smaller size also helps reduce weight and installation time. And while the capital cost is higher, Pax claims a 3-5 year payback, due to increased energy efficiency, reduced water dumping and a reduction in chemical dosing.

Case Study – The Eden Project

Eden Project biodomes

The architect Michael Pawlyn (of Grimshaw Architects and Exploration Architecture) acknowledges that the industrial revolution (or “fossil fuel age”) has allowed human design and engineering to drift away from a symbiotic relationship with nature and an innate understanding of natural solutions.

However, he professes an optimistic attitude that an emerging “ecological age” allows designers to revisit the benefits available through biomimicry – although with the added advantage of improvements in scientific knowledge and better design tools.

Pawlyn does distinguish between “biomorphism” and a functional application of biomimicry. He notes that modern architects have emulated forms from nature to produce majestic creations, but that a “functional revolution of sorts” is required so practitioners in the built environment can bring forward the functional benefits available through biomimicry. Hence Pawlyn has a strong desire to implement functional biomimetic strategies to improve building design.

Six key objectives are targeted: structural efficiency, materials, waste, water, controlling the thermal environment and energy. In a methodological sense, Pawlyn’s approach has similarities to the “challenge to biology” Design Lens.

The Eden Project in Cornwall, England (by Grimshaw) was conceived as the world’s largest greenhouse. The design brief called for suitable structures to house and nurture a diverse range of plant species for a public conservation facility and tourist attraction. The construction site also posed challenges – it was a decommissioned china-clay mine pit.

Designers were inspired by the formation and interconnectivity of soap bubbles, and realised that a string of interconnected “bubbles” of varying diameter would fit to the uneven ground. As well as situate the greenhouses within the mine, designers also wanted to improve structural efficiency and analysed many natural possibilities, including carbon molecules, pollen grains and single-celled organisms such as radiolaria.

The biodomes were thus constructed using arrangements of pentagons and hexagons in geodesic patterns, as this was the most efficient means to create the spherical shapes required. The design was optimised to maximise daylight penetration. As traditional glazing would have been too heavy to fill the transparent spaces between structural members, Ethylene tetrafluoroethylene was selected for its low density and transparency. By creating a triple-layer element, ETFE “pillows” could be fashioned to provide more insulation capacity than traditional glazing. The use of ETFE created a 100-fold decrease in weight compared with traditional glazing. ETFE also had a positive feedback effect: fewer structural members were required, allowing in even more daylight and reducing the requirement for artificial heating, while also reducing costs. Ultimately the project required “a fraction of the resources of a conventional approach”.

Overall, the Eden Project successfully exemplifies a design methodology that seeks to identify specific characteristics from natural systems in order to abstract those characteristics (in detail) to improve or innovate human technology. The project reinforces both the need for clear design objectives and abstraction as a necessary component of the translation from biology to technology. As the designers’ goal is to transfer functional characteristics to the project, emphasis is placed on the abstraction to a technological medium, so that natural features can be successfully emulated, rather than directly copied or visually mimicked.

Finally, the Eden Project designers sought to evaluate their designs against known benchmarks, quantifying improvements in performance. This aligns with the guidance of Biomimicry 3.8, which asserts that function is the most important factor in the application of biomimicry.

Conclusion

While the natural world has been a source of inspiration for building design since ancient times, it is only recently that architects and engineers have begun to explore the performance benefits that functional biomimicry can bring to the built environment.

To this end, there are currently a number of viable methodologies available to engineers to source relevant biological ideas and then translate these to the technological domain. The Biomimicry 3.8 Design Lens, augmentation of the Engineering Design Process and BioTRIZ, among others, all provide designers tools to successfully employ functional biomimicry to drive more ecologically sustainable, better performing buildings.

Furthermore, advances in the breadth and depth of biological knowledge, along with easier access to this information, provide an abundance of biological inspiration for building design. Access to abundant biological information, along with relevant methodologies for abstraction and translation, provides for an acceleration in the prevalence of functional biomimicry in the built environment in the near future.

Matthew Webb is a sustainability consultant at Umow Lai. He is currently completing his PhD at the University of Melbourne, focusing on the application of functional biomimicry to non-residential building facades. He recently spoke at AIRAH’s The Future of HVAC 2014 Conference on functional biomimicry applications.

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