What inspires you about mineralogy?

I started studying geology and became fascinated by the idea of revealing the secrets of Mother Nature through analysing pieces of her we find on the surface. It is similar to a forensic attitude – trying to understand the processes that happened at a time you were not there, at a depth you cannot get to and at a temperature you can hardly handle – and you have to prove the story you come up with using hard facts.

These fascinations led me to do a PhD in Experimental Petrology at Hobart, Tasmania. We tried to tie our findings in rocks together with high-temperature/high-pressure experiments we performed, and interpreted them with physico-chemical theories, namely, thermodynamics of phase relations. This

resulted in developing tools for petrologists and mining information about how chemical analyses of minerals in rocks can be turned into information about the temperatures and pressures at which the rocks originated or transformed.

Why did you decide to pursue a career in this subject?

Mineralogy can be thought of as the materials science section of geosciences and I pursued a combination of experiments, analyses and theories directed towards understanding the processes and structures of materials. Later in my career, I simply opened up my considerations for all other inorganic and composite materials of interest. When I moved to the Max Planck Institute for Metals Research in Stuttgart, rocks

became ceramics, the heat of volcanoes became furnaces for sintering, and transformations in the depth became oxidation and corrosion processes in plants and demanding applications.

When the quest to add properties like strength is included, the game becomes understanding the relation between making structures and the resulting properties. This led me to the subject I represent in Tübingen – applied mineralogy. We still try to teach our students the special position of mineralogy: combine the methods and theories of physics and chemistry with analytical treatments and try to unravel the processes materials can tell you about.

Can you discuss some of the methods you use in your research and explain what makes these unique?

Professor Dr Klaus G Nickel forms part of an interdisciplinary team using plants and animals as a source of inspiration for architectural developments. He discusses his specific interests, the unique methods employed in the project and his fascination with nature relating to his research

Looking to Mother Nature for inspiration

INTERNATIONAL INNOVATION

BIOLOGICAL ENGINEERING

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NATURE HAS ALWAYS been a major source of inspiration for those who design and build physical structures. Leonardo da Vinci studied the flight and anatomy of birds to inform his sketches of ‘flying machines’, while the Wright Brothers claimed their inspiration for inventing and building the world’s first aeroplane came from observing pigeons in flight.

The practice of taking inspiration from nature to solve complex human problems has proved so valuable that a term, ‘biomimetics’, was coined for it in the 1950s. Plants, animals and other living organisms have, through a process of natural selection, become well-adapted to their specific environments, in terms of structure and materials. This has prompted scientists from around the world to look to the intricacies of the natural world to assist their research and derive technological developments from it.

In acknowledgement of the key lessons that can be learned by studying nature and its intricacies, a large collaborative research centre, SFB-TRR 141 (SFB), has been established in Germany. SFB is a programme with the subtitle ‘Biological Design and Integrative Structures – Analysis, Simulation and Implementation in Architecture’ and, as such, attempts to extract and abstract principles found in natural constructions, to improve knowledge about the natural world – a process known as reverse biomimetics. Once identified, these principles are used to provide technical solutions for the building trade.

COMBINING COMPLEX CHARACTERISTICSThe building sector often requires a combination of lightweight constructions with high-energy dissipation capacity and puncture resistance. Buildings that can incorporate

such complex characteristics are especially necessary in areas where earthquakes occur frequently, and avalanches and rock fall events pose a danger. However, they are vital for buildings where maintaining integrity is essential, such as in chemical industries or power plants.

Thus, researchers at SFB have focused their attention on natural structures characterised by multiple networked functions; structures that boast multi-layered, finely tuned and highly differentiated combinations of a basic molecular components. Taking both plants and animals as their source of inspiration, a team composed of researchers from the Universities of Tübingen, Stuttgart and Freiburg investigated the bark of the Giant Sequoia tree – the largest living thing by volume – and the spines of pencil and lance sea urchins.

Researchers from the University of Tübingen, University of Stuttgart and University of Freiburg are analysing biological designs and structures to improve architectural processes. With a specific focus on energy dissipation on load bearing systems and facades, their findings could positively impact on the ecological and economical needs of society

Germany: a natural environment for biomimetics

In terms of analytics, we use our spectrum of mineralogical techniques, from electron microscopy to Raman spectroscopy, X-ray fluorescence and diffraction to characterise the biological role models and new biomimetic materials. Using a combination of these techniques to measure at a single, identical micrometre-sized spot is what makes our methodology unique. We need chemical, structural and textual information to assess why the natural construct behaves the way it does.

When looking at natural objects, characterising the properties is always a challenge. The engineering or physics methods we employ are constructed for well-defined samples – homogenous, geometrically simply and reproducible, but nature rarely provides such samples. Instead, there are all sorts of variations. Altering samples to comply with your investigations forces you to negate the finely tuned order within nature, so the numbers you measure and results you obtain become meaningless. We therefore develop local probing methods like our punch

penetration test for porous material to obtain quantitative numbers for such complicated issues as energy dissipation.

What do you consider the most fascinating aspects of nature in relation to your research?

The constructions within nature work differently from ordinary human engineering. Our constructions, such as cars, are made from thousands of different pieces, each one optimised for a specific function and we end up with a complex array of materials, which have to be put together. Nature works with very few materials and invents new structural variants to realise a great number of different functions simultaneously. Nature involves many slow self-organising processes, which is a challenge because we do not want to wait years to manufacture a construction. However, the 3D-generation of components is similar to nature’s methods and it is developing fast and will revolutionise our way to make materials.

Which major challenges do you face in your research?

Each piece of nature is a unique sample, with the individual history of the being and species from which it is developed inscribed in the material. The hierarchical fashion of building with differentiations on different levels yields different properties at different scales; a nanoscale testing does not give the same answer as one of a cm-sized probe. When the properties of a component are defined by material, structure and scale of observation simultaneously, it becomes difficult to describe a property quantitatively. To overcome this inherent difficulty, it is necessary to go to sophisticated simulation methods that help us to understand the many varying results of our experimental methods. 

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Whereas the Giant Sequoia’s bark is made up of a fibrous and multi-layered system, the sea urchins present a new concept to dissipating energy in brittle construction materials. Such properties have tremendous potential for applications in the building construction sector, especially with their combination of low weight, recyclability and high protection efficiency.

AN EXTRAORDINARY BREADTH OF EXPERTISEOne of the most fascinating aspects of the SFB programme is the number of areas of expertise required to collate, translate and make use of the information gathered through biomimetic practices. The University of Tübingen’s Professor Dr Klaus Nickel is a mineralogist on the project and a keen advocate for adopting an interdisciplinary approach to make the best use of nature’s teachings. “The biologists bring in their knowledge about the forms and functions of natural creatures and how to investigate them, while the civil engineers contribute skills of modelling, simulation and manufacturing building materials,” he explains. “We mineralogists look at the materials science of inorganics, including the testing, analysis, theoretical treatment and synthesis.”

All of the individual projects work towards the ultimate aim of finding effective means of using inspirations from nature to develop new building materials. Thus, each project cross-links to other projects, and different people provide input at various stages. The art is to reduce the complexity usually found in natural constructions, creating a simple, man-made construction that still retains the original desired natural properties.

RESEARCH RELATED TO SOCIETAL NEEDS

Developments in computational designs, simulations and fabrications provide new and exciting possibilities for transferring principles found within the bark of the Giant Sequoia and the spines of sea and lance urchins to macro-scale building construction. As well as providing revolutionary building practice solutions for a range of locations around the world, the team also aims to transfer the inherent ecological properties of natural constructions. “The project we are working on aims for more lightweight constructions, which save material and resources, thereby limiting pollution,” explains Nickel. “Furthermore, we aim for pure, one-type materials – an important precondition for efficient recyclability of building materials.”

In addition to these tangible ecological and environmental benefits, the team is working towards changing the mindsets of scientists, engineers and the wider public, in terms of conceptualising nature as being an important educational tool that can provide an extremely valuable service to society. How beautiful – to think of nature helping us improve all of our lives in a way that creates an ecologically sound environment.

Scientists from around

the world […] look to

the intricacies of the

natural world to assist

their research and

derive technological

developments from it

INTERNATIONAL INNOVATION3

PLANTS AND ANIMALS AS A SOURCE OF INSPIRATION FOR ENERGY DISSIPATION IN LOAD BEARING SYSTEMS AND FACADES

OBJECTIVEBiomimetic research for architecture and building construction: science to learn from nature and to benefit society’s ecological and economic needs.

KEY COLLABORATORSProfessor Dr Ing Jan Knippers, Institute of Building Structures and Structural Design (ITKE), University Stuttgart, Germany

Professor Dr Dr Eh Dr hc Werner Sobek, Institute for Lightweight Structures and Conceptual Design (ILEK), University of Stuttgart

Professor Dr Thomas Speck, Plant Biomechanics Group Freiburg, Botanischer Garten, University Freiburg, Germany

FUNDINGGerman Research Foundation (DFG)

Project is part of the Collaborative Research Center ‘Biological Design and Integrative Structures – Analysis, Simulation and Implementation in Architecture’ SFB TRR 141

CONTACTProfessor Dr Klaus G Nickel

University Tübingen FB Geosciences, Applied MIneralogy Wilhelmstr 56 Room 152 72074 Tübingen Germany

T +49 7071 2976802 E klaus.nickel@uni-tuebingen.de

www.trr141.de/index.php/research-areas-2/a02

http://bit.ly/MineralogyandGeodynamics

www.researchgate.net/profile/KG_Nickel

KLAUS G NICKEL has been Professor of Applied Mineralogy at the University of Tübingen since 1992, specialising in the materials science of technical ceramics (phase

relations, chemical and mechanical properties of alumina, zirconia, carbon, carbides, nitrides, borides). A current focus is on the biomimetics of porous technical and biological materials.

INTEGRATIVE RESEARCH FOR DESIGNING INTEGRATIVE STRUCTURES

The highly collaborative research centre, Sonderforschungsbereich (SFB) TRR 141, is an interdisciplinary home for the institutions and researchers involved in the ‘Plants and animals as source of inspiration for energy dissipation in load bearing systems and facades’ project. With funding from the German Research Foundation (DFG), the project melds expertise from three different universities in Germany in different scientific areas to achieve its aims.

The team based at the University of Stuttgart focuses on the fields of architecture and engineering, which are broken down into the sub-fields of modelling and simulation, design and construction, and fabrication and manufacturing.

The teams based at University of Freiburg (UoF) and University of Tübingen (UoT) focus on the field of natural sciences. Where UoF concentrate on the sub-fields of biology and physics, UoT concentrate on the sub-fields of geosciences and evolutionary biology.

This transregional and transdisciplinary approach is vital to the success of the project. To find out further information about the people involved in this exciting project visit: www.trr141.de/index.php/people

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