Dr. Buddy D. Ratner

University of Washington Engineered Biomaterials (UWEB), USA.

Dr. Buddy D. Ratner is the Director of University of Washington Engineered Biomaterials (UWEB) Engineering Research Center and the Michael L. and Myrna Darland Endowed Chair in Technology Commercialization. He is Professor of Bioengineering and Chemical Engineering at the University of Washington. Dr. Ratner received his Ph.D. (1972) in polymer chemistry from the Polytechnic Institute of Brooklyn. From 1985-1996 he directed the NIH-funded National ESCA and Surface Analysis Center for Biomedical Problems (NESAC/BIO). In 1996, he assumed the directorship of UWEB. He is the editor of the Journal of Undergraduate Research in BioEngineering, on the advisory board of Biointerphases and serves on the editorial boards of ten other journals. He is a past president of the Society For Biomaterials. He has authored over 400 scholarly works and has 18 issued patents. Ratner is a fellow of the American Institute of Medical and Biological Engineering (AIMBE), the American Vacuum Society, the American Association for the Advancement of Science (AAAS) and the International College of Fellows Biomaterials Science and Engineering (IUS-BSE). Ratner served as president of AIMBE, 2002-2003. In 2002 Ratner was elected a member of the National Academy of Engineering, USA. In 2003 he was elected President of Tissue Engineering Society of North America (TESNA). He is now on the council of the Tissue Engineering and Regenerative Medicine International Society (TERMIS). He has participated in the launch of four companies based on technologies from his laboratory. He has won numerous awards including Medard W. Welch Award of the American Vacuum Society (2002), Founders Award of the Society for Biomaterials (2004), C. William Hall Award from the Society for Biomaterials (2006), the BMES Pritzker Distinguished Lecturer Award (2008) and the Acta Biomaterialia Gold Medal (2009). His research interests include biomaterials, tissue engineering, polymers, biocompatibility, surface analysis of organic materials, self assembly, nanobiotechnology and RF-plasma thin film deposition.

Abstract

Materials, Healing and Regeneration: The Landscape Shifts

Millions of medical devices made of synthetic or modified natural materials all trigger a similar reaction, the foreign body reaction (FBR). Biocompatibility, for materials that pass routine cytotoxicity assays, is largely associated with a mild foreign body reaction, i.e., a thin, avascular, non-adherent foreign body capsule. The implant is within a “dead-zone” of acellular scar, hardly what would generally be thought of as “biointegration.” The contemporary tissue engineering paradigm would suggest that synthetic polymers and scaffolds lacking cellular, biomolecule or biomimetic elements give this fibrotic, avascular healing reaction, the FBR.

Based on studies over the past 10 years at the University of Washington, a class of biomaterials will be described that readily integrates into tissue and stimulates spontaneous reconstruction of tissue. The material is made by sphere-templating of synthetic polymers. All pores are identical in size and interconnected. Studies from our group have shown optimal healing (as suggested by induced vascularity and minimal fibrosis) for spherical pores of approximately 30 micron size. The integrative healing effect noted is independent of biomaterial – similar results are observed with sphere-templated silicone rubber and pHEMA hydrogel. In addition, surface chemical modification of the hydrogel with carbonyl diimidazole (CDI), or immobilization on the hydrogel of collagen I or laminin did not change the healing response. Also, good healing results have been seen upon implantation in skin (subcutaneously, percutaneously), heart muscle, sclera, skeletal muscle, bone and vaginal wall. This talk will describe these sphere-templated materials, and also discuss new biodegradable polymers developed to be compatible with the sphere-templating process. The special biological reaction seems to be driven by macrophages and biology of the reaction will be described. Thus, such materials may represent a path to cell-free, biologic-free tissue engineering. Others have seen similar healing results, via completely different materials strategies, generally involving biological molecules. The in vivo results from our group and from other groups suggest we are on the cusp of a revolution in healing, biocompatibility, biomaterials integration and tissue reconstruction – the landscape is shifting.

Dr. Ullrich Scherf

Bergische Universität Wuppertal, Macromolecular Chemistry Group and Institut für Polymertechnologie, Germany.
E-mail: scherf@uni-wuppertal.de

Ullrich Scherf studied chemistry at the Friedrich-Schiller-Universität in Jena, GDR, gained his Diploma in 1983, and received his Ph.D in 1988 working with Prof. Dr. H.-H. Hörhold. Then he spent a year at the Institut für Tierphysiologie, Universität Jena (Prof. Dr. H. Penzlin). He joined the MPI für Polymerforschung in 1990 and got his habilitation in 1996. From September 2000 to August 2002 he was professor for polymerchemistry at the Institute for Physical and Theoretical Chemistry , University of Potsdam. Since September 2002 he is professor for macromolecular chemistry at the Bergische Universität Wuppertal.

Abstract

Chemical Design of Functional Oligomers and (Co)polymers for Electronics Applications

The contribution presents synthetic strategies towards a systematic control on morphology and optical/electronic properties of conjugated oligomers and (co)polymers. The presented examples include novel “low bandgap” (co)polymers which a potential application in “bulk heterojunction”-type organic solar cells [1] or photodetectors, all-conjugated block copolymers [2] and tactic conjugated polymers. Our all-conjugated diblock copolymers showed a hierarchical self assembly into vesicular and lamellar nanostructures.

References
[1] Moulé, A. J.; Tsami, A.; Bünnagel, T. W.; Forster, M.; Scharber, M.; Koppe, M.; Morana, M.; Brabec, C. J.; Meerholz, K.; Scherf, U.; Chem. Mater. 20 (2008) 4045
[2] Scherf, U.; Gutacker, A.; Koenen, N.; Acc. Chem. Res. 41 (2008) 1086

Dr. Subash Mahajan

School of Materials, Arizona State University, USA
E-mail: smahajan@asu.edu

Research Interests
Structure- property relations in functional materials and deformation behavior of solids.

Professional Experience

July 2006	Regents’ Professor and Director, School of Materials, Arizona State University, Tempe
Nov. 2000- July 2006	Professor and Chair, Chemical and Materials Engineering, Arizona State University, Tempe
Jul. 2000-Oct. 2000	Professor and Interim Chair, Chemical and Materials Engineering, Arizona State University, Tempe
Jul. 1999-Jun. 2000	Professor and Associate Chair, Chemical, Bio & Materials Engineering, Arizona State University, Tempe
1997 – Jun. 1999	Professor of Electronic Materials, Arizona State University, Tempe
1993	Visiting Professor, Ecole Centrale de Lyon, Ecully, France (summer)
1991	Visiting Professor, University of Antwerp, Antwerp, Belgium (spring)
1983-97	Professor of Electronic Materials, Carnegie Mellon University, Pittsburgh
1981-83	Research Manager, AT&T Bell Laboratories, Murray Hill
1976	DAAD Fellow at the University of Göttingen, Göttingen, Germany (spring and summer)
1971-83	Member of Technical Staff, AT&T Bell Laboratories, Murray Hill
1968-71	Harwell Fellow, Atomic Energy Research Establishment, Harwell, England
1965-68	Research Metallurgist, University of Denver, Denver
1961-65	Research Assistant, University of California, Berkeley

Education

B.Sc.		Panjab University, India; First Rank in the State	1959
B.E.	Metallurgy	Indian Institute of Science, India; First Rank in the Class	1961
Ph.D.	Materials Science and Engineering	University of California, Berkeley	1965

Abstract

Self-Assembled Nanostructures in Mixed Group III Nitrides

The group III nitrides are scientifically interesting and technologically relevant materials. They crystallize in the wurtzitic structure which consists of two interpenetrating HCP sub-lattices that are displaced from each other. The group III atoms reside on one sub-lattice, whereas the N atoms occupy the second sub-lattice. An interesting question is whether or not the atomic species in mixed III nitride layers, such as InGaN, AlGaN, and InAlGaN, are distributed at random on their respective sub-lattice.

We will demonstrate that the layers containing group III species differing in their covalent tetrahedral radii exhibit two types of deviations from randomness; phase separation and atomic ordering. Phase separation in layers occurs on the surface while the layer is growing and produces nanostructures consisting of In – and Ga-rich regions. Wavelengths of the resulting modulations are very sensitive to In content of the layer; higher the In content, smaller the wavelength of modulation. Furthermore, we will show that phase separation may be suppressed in very thin quantum wells due to the existence of compressive stresses at InGaN/GaN interfaces. Arguments will be developed to rationalize the preceding observations.

The mixed group II nitrides, such as InGaN and AlGaN, also exhibit atomic on the (0001) planes. For example in InGaN layers, the atomic arrangement on the (0001) planes changes from A(In, Ga) a(N)B(In, Ga)b(N)A(In,Ga)a(N)…to A(Ga)a(N)B(In)b(N)A(Ga)a(N)B(In)b(N)…as a result of ordering. Similar features are seen in mixed III-V epitaxial layers. We will show that they affect optical and electronic properties and the degradation behavior of light emitters.

Dr. Darrel G. Schlom

Department of Materials Science and Engineering, Cornell University
E-mail: schlom@cornell.edu

Darrell Schlom is a Professor in the Department of Materials Science and Engineering at Cornell University. After receiving a B.S. degree from Caltech, he did graduate work at Stanford University receiving an M.S. in Electrical Engineering and a Ph.D. in Materials Science and Engineering. He was then a post-doc at IBM’s research lab in Zurich, Switzerland in the oxide superconductors and novel materials group managed by Nobel Prize winners J. Georg Bednorz and K. Alex Müller. In 1992 he joined the faculty at Penn State in the Department of Materials Science and Engineering, where he spent 16 years before joining the faculty at Cornell in 2008. His research interests involve the replacement of SiO2 as the gate dielectric in MOSFETs and the heteroepitaxial growth and characterization of oxide thin films, especially those with functional properties (ferroelectric, piezoelectric, ferromagnetic, or a combination of these properties), including their epitaxial integration with semiconductors. His group synthesizes these oxide heterostructures using molecular-beam epitaxy (MBE). He has published over 300 papers and has 8 patents. He was awarded a Semiconductor Research Corporation Fellowship for his graduate studies at Stanford, the Ross N. Tucker AIME Electronics Materials Award in 1989, an IBM Invention Achievement Award in 1991, an ONR Young Investigator Award in 1993, the NSF Young Investigator Award in 1993, an Alexander von Humboldt Research Fellowship in 1999 for his sabbatical stay in Jochen Mannhart’s group at the University of Augsburg, the American Association for Crystal Growth Young Author Award in 1999, the ASM International Bradley Stoughton Award for Young Teachers in 1999, a Semiconductor Research Corporation Inventor Recognition Award in 2004, and the Penn State Faculty Scholar Medal in Engineering in 2006. He was also elected Fellow of the American Physical Society in 2003, served on the MRS Board of Directors from 2005-2007, and was named Distinguished Professor by Penn State in 2007. In 2008 he was awarded the MRS Medal for “Fundamental contributions to the materials science of oxides underlying current and future electronic devices.”

Abstract

Gate Oxides beyond SiO2 and the High K Materials Revolution

A major materials milestone has been achieved that transforms the materials makeup of silicon-based field-effect transistors: the SiO2 gate dielectric has been replaced by a hafnium-based dielectric in microprocessors produced by leading manufacturers. The incredible electronic properties of the SiO2/silicon interface are the reason that silicon has dominated the semiconductor industry and helped it grow to over $250 billion in annual sales. The shrinkage of transistor dimensions (Moore’s law) has led to tremendous improvements in circuit speed and computer performance. At the same time, however, it has also led to exponential growth in the static power consumption of transistors due to quantum mechanical tunneling through an ever-thinner SiO2 gate dielectric. This spurred an intensive effort to find an alternative to SiO2 with a higher dielectric constant (K) to temper this exploding power consumption and enable Moore’s law to continue. In this talk the comprehensive materials analysis to identify silicon-compatible materials that go beyond SiO2 (i.e., with higher K and sufficient bandgap) will be described,1 3 together with how these materials have enabled improvements in MOSFETs, DRAM, and emerging semiconductor devices.⁴

1 K.J. Hubbard and D.G. Schlom, J. Mater. Res. 11 (1996) 2757-2776.
2 C.A. Billman, P.H. Tan, K.J. Hubbard, and D.G. Schlom in Ultrathin SiO2 and High-K Materials for ULSI Gate Dielectrics, edited by H.R. Huff, C.A. Richter, M.L. Green, G. Lucovsky, and T. Hattori, Vol. 567 (Materials Research Society, Warrendale, 1999), pp. 409-414.
3 D.G. Schlom and J.H. Haeni, MRS Bull. 27 (2002) 198-204.
4 D.G. Schlom, S. Guha, and S. Datta, MRS Bull. 33 (November 2008 issue).

Dr. Guozhong Cao

University of Washington, Department of Materials Science and Engineering
E-mail: gzcao@u.washington.edu

Dr. Guozhong Cao is Boeing-Steiner Professor of Engineering, Professor of Materials Science and Engineering, and Adjunct Professor of Chemical and Mechanical Engineering at the University of Washington and Affiliate Professor of Chemistry in Chongqing University, China. He received his PhD degree from Eindhoven University of Technology (the Netherlands), MS from Shanghai Institute of Ceramics, and BS from East China University of Science and Technology (China). He has published over 250 refereed papers, authored and edited 5 books and 3 conference proceedings, and presented over 100 invited talks and seminars. Currently, Dr. Cao serves as the editor of Annual Review of Nano Research and associate editor of Journal of Nanophotonics. His recent research is focused mainly on nanomaterials for energy related applications including solar cells, lithium-ion batteries, supercapacitors, and hydrogen storage.

Abstract

Engineering nanomaterials and interfaces for energy conversion and storage

The increasing demand for fossil fuels and the environmental impact of their use are continuing to exert pressure on an already-stretched world energy infrastructure. The last decade has brought significant progress in cleaner and more efficient energy technology. However, further development is limited by the properties of existing materials. For example, thermoelectric materials typically possess low power conversion efficiency due to inherent coupling of charge and heat transfer in existing materials. Likewise, portable electric power sources, such as batteries, have low power density due to limited electrode kinetics or mass transport. A recent promising avenue of research has been nanostructured materials, which have demonstrated significantly enhanced energy conversion efficiency in batteries, catalysis, and solar cells due to their large surface to volume ratios and favorable transport properties.

In this presentation, I will use three examples to illustrate how energy conversion and storage efficiency can be significantly improved through careful design and engineering of materials in the nanometer and micrometer scales and through surface chemistry modification. The first example is popcorn-style dye-sensitized solar cells, in which the controlled micro-sized aggregation of nanocrystallites resulted in light scattering inside the photoelectrode. This led to a greater than 200% enhancement in the power conversion efficiency and to a 40% reduction in the amount of photoelectrode. The second example is nanostructured or hierarchically structured electrodes for lithium-ion batteries. Nanostructured and hierarchically structured electrodes have demonstrated specific energy and specific power improvements of up to 2 orders of magnitude. Further enhancement can be achieved through modifications in the surface chemistry, crystallinity and crystal structure. The last example is the tuning of a dehydrogenation reaction through surface chemistry modification and by confining the hydrides inside the nanopores of a highly porous carbon scaffold.