David R. Clarke

David R. Clarke is a material scientist and the inaugural Extended Tarr Family Professor of Material Science and Applied Physics at Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). He is the principal investigator of the Materials Discovery and Applications Group.

The American Ceramic Society (ACerS) considers Clarke's paper "On the Equilibrium Thickness of Intergranular Glass Phases in Ceramic Materials" (1987) one of the 11 best papers in 110 years of publications on ceramics and glasses. He is the inaugural holder of the position of Extended Tarr Family Chair of Materials and Applied Physics at Harvard University. metals, polymers and thermoelectrics.

He is best known for his work on the fundamentals, properties and applications of ceramics.

In 1987 Clarke proposed that nanometer-thick intergranular films (IGFs) in ceramics exhibit an equilibrium thickness. He applied a model adapted from the wetting community to explain their existence and the consequences for their properties at high-temperatures. The equilibrium thickness represents a balance among attractive and repulsive interactions at interfaces. Clarke proposed a model for the discovery of low thermal conductivity ceramics, leading to the identification of a wide range of novel candidates.

Clarke developed novel techniques in piezospectroscopy which are used worldwide to measure stress in materials. Significant contributions include the observation of dislocations at crack tips in silicon, the loss of crystalline structure in silicon and germanium following indentation, and identifying a failure mechanisms in thin films.

His group has studied thermal barrier coatings (TBCs) on turbine blades used in aircraft. They have explored TBC's thermal conductivity and the conditions leading to the degradation and failure of TBCs.

Another area of research is dielectric elastomers, soft materials with good insulating properties that could potentially be used in soft robots. Clarke's lab have combined materials in a way that avoids two problems that limit the design of electrically-controlled soft actuators: high voltage and pre-stretching.

Clarke is a member of the National Academy of Engineering, and is an Associate Editor for the Journal of the American Ceramic Society.

Over the years he has taught a variety of undergraduate and graduate level courses in materials, ranging from introductory classes to courses in phase equilibria, optical materials, phase transformations, thermodynamics and composites. He currently teaches seminars on "Glass" and "Materials, Energy and Society" at the undergraduate Freshman level, and the required course on "Fundamentals of Heat Transfer" course for students studying Mechanical Engineering at Harvard University. 2008, Author of one of the 11 most significant papers in the 110 years of publication on ceramics and glasses, listed by the American Ceramic Society 2008, New Materials Award, from the National Institute of Materials Science (Japan), (jointly with A. G. Evans and C. G. Levi, UCSB) 1999, Robert B. Sosman Memorial Award, ACerS 1999, Van Horn Lectureship, Case Western Reserve University 1999, Elected to the National Academy of Engineering 1998, Morrison Lectureship, Brockhouse Institute, McMaster University 1995, Academician, International Academy of Ceramics 1993, Alexander von Humboldt Foundation Senior Scientist Award 1986, Fellow of the American Physical Society

Selected publications