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TU Dresden » Faculty of Mechanical Science and Engineering » Institute for Materials Science » Chair of Materials Science and Nanotechnology



Monday, 10 October 2011
(at 11:00 in room seminar room B1, Max Bergmann Center of Biomaterials Dresden, Budapester Strasse 27)
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From atoms to structures - how spiders turn weakness into strength

Markus J. Buehler

Laboratory for Atomistic and Molecular Mechanics
Massachusetts Institute of Technology
  U.S.A.  






This talk will explain how materials in biology are synthesized, controlled and used for a variety of purposes-structural support, force generation, catalysis, or energy conversion-despite severe limitations in available energy, quality and quantity of building blocks. By incorporating concepts from chemistry, biology and engineering we describe how computational materials science has led the way in identifying the core principles that link the molecular structure of proteins at scales of nanometers to physiological scales at the level of tissues, organs, and organisms. We demonstrated that the chemical composition of biology's materials plays a minor role in achieving functional properties. Rather, the way components are connected at different length-scales defines what material properties can be achieved, how they can be altered to meet functional requirements, and how they fail in disease states. We have achieved this by using the world's fastest supercomputers to predict properties of complex materials from first principles, in a multiscale modeling approach that spans many orders of magnitude in scale. This method, combined with experimental studies, allows us to build virtual "in silico" material models that provide unseen insight into the workings of natural and synthetic materials from the bottom up.
We demonstrate this approach in a case study of spider silk, one of the strongest yet most flexible materials in Nature, despite being made out of some the simplest, most abundant and intrinsically weak proteins, including weak hydrogen bonding. We discovered that the great strength and flexibility of spider silk-exceeding that of steel and other engineered materials-can be explained by the material's unique structural makeup that involves multiple hierarchical levels from the nano- to the macroscale. These hierarchical levels span from the genetic information that defines the protein sequence to the structural scale of an entire spider web. Each level contributes to the overall properties, but the remarkable properties emerge because of the synergistic interaction across the scales where the sum is more than its parts. This concept explains how spider silk provides extreme functionality despite the simple basis in its makeup. By translating this insight gained from the study of natural materials such as spider silk to engineered materials such as carbon nanotube fibers, graphene composites or metal-polymer films, our research has resulted in an engineering paradigm that facilitates the design of sustainable materials starting from the molecular level, leading to the formation of hierarchical structures that span all scales from nano to macro, and leading to a merger of the concepts of structure and material.
By utilizing a mathematical tool from category theory we illustrate the hierarchical materials design concept by drawing an analogy to a seemingly far and distant field-music. Reminiscent of protein materials, the integrated use of structures at multiple scales is the key to provide superior functional properties despite limitations in available building blocks, a set of musical instruments such as piano, violin or cello. In music, tones are played at different pitch, accentuation or duration and then assembled into melodies. The collective interaction of melodies, played by different instruments and arranged in a particular way, eventually results in the powerful expression of a symphony. We discuss analogies with other biological materials such as collagen in bone, or intermediate filaments in cells, and present general approaches towards the design of adaptable, mutable and active materials. Our work enables a paradigm shift in the design of materials that exceed the properties of natural ones while being constructed with low energy use and from abundant and intrinsically poor material constituents.

Brief Bio:

Markus J. Buehler is an Associate Professor in the Department of Civil and Environmental Engineering at the Massachusetts Institute of Technology, where he directs the Laboratory for Atomistic and Molecular Mechanics (LAMM). He is the Director of the MIT-Germany Program, Co-Director of the MIT Computation for Design and Optimization Program, and the Head of the Mechanics and Materials Group in the Department of Civil and Environmental Engineering. Buehler has published more than 170 articles on computational materials science, nanotechnology and nanoscience, authored two monographs, and given several hundred invited, keynote and plenary talks. He was cited as one of the top engineers in the United States between the ages of 30-45 through invitation to the National Academy of Engineering-Frontiers in Engineering Symposium of the National Academy of Engineering. Buehler received the National Science Foundation CAREER award, the United States Air Force Young Investigator Award, the Navy Young Investigator Award, and the DARPA Young Faculty Award and his work was recognized by the Presidential Early Career Award for Scientists and Engineers (PECASE). He recently received the Harold E. Edgerton Faculty Achievement Award for exceptional distinction in teaching and in research or scholarship, the highest honor bestowed on young MIT faculty. Other major awards include the Thomas J.R. Hughes Young Investigator Award, the Sia Nemat-Nasser Medal, the Rossiter W. Raymond Memorial Award, the Stephen Brunauer Award, the Alfred Noble Prize, and the Leonardo da Vinci Award. Buehler serves as a member of the editorial board of several international journals including: BioNanoScience (as Editor-in-Chief), Roy. Soc. Interface, PLoS ONE, Int. J. Appl. Mech., Acta Mech. Sinica, J. Mech. Beh. Biomed. Mat., J. of Engrg. Mech., J. Nanomech. Micromech, and the J. Comp. and Theor. Nanosci. He is the founding chair of the Biomechanics Committee at the Engineering Mechanics Institute of ASCE, a member of the U.S. National Committee on Biomechanics, and Co-Chair of the Nanoengineering in Biology in Medicine Steering Committee of ASME.



slides (pdf)

Invited by G. Cuniberti

Within the Max Bergmann Lecture

last modified: 2018.10.24 Mi
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