zq07 fall 2013
People: Interview
ing the structural foundation and how to actually construct the kinds of structures we see in many natural systems, which are often complex hierarchical geometries. While engineers have traditionally created things by carving away materials – hence called subtractive manufacturing – nature typically uses additive manufacturing and makes materials by assembling them molecule by molecule. New methods of manufacturing need to be developed that allow us to build the structures we observe in nature. We know that the basic code of life is DNA and that proteins, sugars, and similar molecules are the universal building blocks of materials in the living world. However, how we connect molecules to generate materials, organs or organisms that work in a certain way remains a big challenge. For example, while we can make the proteins that comprise a spider web in the lab, we currently have very limited ability to create a complex structure like a spider web or a cocoon in the lab. Many current efforts rely on existing organisms that are altered to produce certain materials, or that do so naturally, such as wood or materials extracted from plants. In the future, we want to find our own ways to produce complex function from simple chemical molecules, with a similar elegance to what nature does, while harvesting matter that exists in abundance. What about taking silica from the sand at the beach, mixing it with proteins from soybeans, and building an airplane all at room temperature and in an aqueous solution that does not involve any toxic chemicals? Turning the weakness of silica or glass into a strong material is impossible for
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Author: Markus J. Buehler
engineers, but is achieved in nature by many sea animals such as diatoms or deep-sea sponges. What areas should we be focusing on to advance the field of biomimicry? A more systematic, mathematic and modeling driven approach that relies on quantitative methods. Currently, there is a lot of ad-hoc and inspirational design happening, some very successful, but we want to apply the power of engineering and science to this field. While some advances have been made, more rigor is needed. This also raises the question of education, which should play a more prominent role. What about educating our undergraduate engineering students in new ways of thinking about materials, to consider the holistic balance of raw materials, energy, byproducts, and durability? These and other fields pose interesting challenges and give opportunities to lead new educational programs. How have you developed your interest in biomimicry/bio-inspired design? For many years I have been intrigued by the diversity of materials nature produces and uses – from wood to bone, spider silk to organs or cells. Yet, these materials are made from some of the most basic chemicals known, at low energy, low temperature, and in water. Engineers are far from replicating these processes and rely on much different methods. To make steel, we need a steel plant that relies on iron ore and substantive amounts of energy. Spiders produce silk threads with the strength of steel at low energy,