MIT Reports to the President 1999–2000
The Center for Materials Science and Engineering (CMSE), an interdepartmental center at MIT, is an innovative and dynamic program in interdisciplinary materials research and education. Funded since 1994, CMSE is the largest of a nation-wide network of twenty-eight Materials Research Science and Engineering Centers (MRSEC) sponsored by the National Science Foundation (NSF).
MIT has an extraordinarily strong and broad effort in materials science and engineering involving approximately 120 faculty members in 11 departments in the schools of science and engineering. Much of the research addresses intermediate-term engineering problems, often with the participation and support of industry. However, the longer-range problems, especially those that require a multi-investigator approach, are often overlooked. In this environment CMSE has a special mission: to encourage research and education in the fundamental science of materials and in the engineering of materials for long-range applications that will meet the needs of society. To accomplish this, CMSE promotes collaboration among MIT faculty and between MIT researchers and the researchers of other universities, industry, and government and nonprofit laboratories.
Collaborative research is encouraged through several mechanisms: interdisciplinary research groups (IRGs), shared experimental facilities (SEFs) and outreach programs. The IRGs, described below, are composed of MIT faculty who, with their students and postdoctoral associates, investigate fundamental scientific questions and pathways to reach significant technological goals that can only be properly explored in a collaborative, multidisciplinary mode. These problems are too large in scope to be addressed by individual faculty members and their students. Collaboration is essential for materials-related science and engineering, even for individual investigators, because such research requires very sophisticated equipment. CMSE provides a mechanism for the purchase and supervision of such equipment in its SEFs. The equipment is made available to the members of the IRGs, individual MIT investigators, and researchers from other university, industrial, government, and nonprofit laboratories.
CMSE also provides seed and initiative funds. While preference is given to young faculty, CMSE uses seed and initiative funds to support research that has the potential of redefining the direction of an existing IRG or leading to the creation of a completely new IRG. Seed funding provides CMSE with the flexibility necessary to initiate high-risk research.
This has been a year of change for the Center. In February, I began an assignment as Interim Dean of Science, replacing Professor Robert J. Birgeneau (Physics). Professor Birgeneau, a member of our Doped Mott Insulators group, was named President of the University of Toronto effective July 1, 2000. Last August, Professor Michael Rubner (Materials Science and Engineering) was appointed as the CMSE associate director and safety officer. Professor Samuel Allen (Materials Science and Engineering) left his position as our education leader to become the executive officer of the Department of Materials Science. He was replaced in this role by Professor Steven Leeb (Electrical Engineering and Computer Science). On a sad note, Professor Toyoich Tanaka (Physics), the leader of our Heteropolymers and Gels Initiative, passed away suddenly on May 20, 2000. He had been a long-time member of the Center and will be missed.
In the past 50 years, semiconductor technology has come to play a vital role in almost every aspect of our daily lives. In the next 50 years, our technology may be just as thoroughly revolutionized by the replacement of electrons with photons (i.e. light) as the carrier of information. Photons have several advantages over electrons, including greater speed, greater information carrying ability, and greater energy efficiency. The key to achieving this advance, and the principal goal of this IRG, is the development of an exciting new class of materials, called photonic crystals, which will allow control of the confinement and propagation of light in very small dimensions, thereby enabling the design and integration of a large number and variety of optical microdevices on a single chip.
Participating faculty and departmental affiliations: H. A. Haus, E. P. Ippen, L. A. Kolodziejski, and H. I. Smith (Electrical Engineering and Computer Science); L. C. Kimerling (Materials Science and Engineering); and J. D. Joannopoulos (Physics).
This group seeks to gain a fundamental understanding of the factors that control the way complex, electronically active polymer systems organize at the molecular level. The knowledge obtained from this work is expected to make it possible to control and significantly enhance the performance of electronic, magnetic, and optical devices based on these materials. The objective of this IRG is to develop the chemistry and processing needed to control the composition and spatial arrangement of constituents of multicomponent polymeric materials with novel electrical and optical properties.
Participating faculty and departmental affiliations: R. E. Cohen (Chemical Engineering); M. Bawendi, R. R. Schrock, and R. J. Silbey (Chemistry); and A. Mayes, M. F. Rubner, and E. L. Thomas (Materials Science and Engineering).
The steady decrease in the size of semiconductor structures that has brought about the information age has also made it possible to study new electronic transport phenomena. Whereas classical transport theory describes the behavior of electrons in macroscopic systems (like conventional transistors), and the quantum mechanics of microscopic systems (like atoms) is reasonably well understood, the intermediate regime, termed mesoscopic, continues to reveal surprises and opportunities for novel electronic devices. In particular, whereas some mesoscopic effects are subtle, those resulting from confining electrons to reduced dimensions (in quantum dots, for example) are very dramatic. It is the goal of this IRG to understand the fundamental physical principles governing transport through and between semiconductor nanostructures created by both self-assembly and lithography techniques.
Participating faculty and departmental affiliations: R. Ashoori, M. A. Kastner, P. Lee, L. Levitov, and X.-G. Wen (Physics); M. G. Bawendi (Chemistry); and E. A. Fitzgerald (Materials Science and Engineering).
It is widely recognized by polymeric material producers that the key to polymer penetration into new product markets is through the optimization of industrial polymers on the market today. Thermoplastics offer major advantages in load-bearing applications because they are inexpensive, light-weight, easily processed into desired form, and recyclable. However, their mechanical properties limit their applicability. Recent advances in the ability to study material microstructure and deformation at multiple length scales have created tremendous new opportunities for developing methodologies for truly designing polymeric material systems. The goal of this IRG is to provide a mechanistic basis for tailoring polymer microstructure in order to achieve dramatic improvements in multiple mechanical properties by exploring and exploiting connections among microstructure, mechanisms and mechanical performance.
Participating faculty and departmental affiliations: A. S. Argon, M. C. Boyce, and D. M. Parks (Mechanical Engineering); and R. E. Cohen, K. K. Gleason, and G. C. Rutledge (Chemical Engineering).
Several of the most interesting phenomena discovered in materials science in the past decade occur in a class of substances called Mott insulators. For example, high critical temperature (Tc) superconductivity occurs when certain copper oxide Mott insulators are doped to make them conducting. The effect of doping on the electronic and magnetic properties of Mott insulators is one of the great unsolved problems in condensed matter physics. The members of this IRG believe that the understanding of high Tc superconductivity, in particular, will require the solution of this larger problem. Apart from the intrinsic scientific interest, a deeper understanding of doped Mott insulators will pave the way for the exploitation and control of this technologically interesting class of materials
Participating faculty and departmental affiliations: R. J. Birgeneau, M. A. Kastner, T. Imai, and P. A. Lee (Physics); F. C. Chou (Research Scientist, CMSE); and R. J. Cava (Chemistry, Princeton University).
Rechargeable Li batteries with a solid polymer electrolyte (SPE) could be the ultimate power storage device due to their high potential energy density and low cost. Li-SPE imposes no limitations on the shape of the battery and is inexpensive to process, in contrast to current battery technology based on liquid electrolytes. Development is impeded by materials problems that are difficult because of the interaction between electronic, chemical and mechanical phenomena. The members of this initiative have expertise in electrochemistry polymer synthesis and characterization, oxide synthesis and first-principles electronic structure calculations. The objective is to develop the basic science behind rechargeable Li batteries, and use it to develop superior materials for this application. Initially, the focus will be on the development of a block copolymer solid electrolyte (BCE), and a high-energy density, low-cost, intercalation oxide for the cathode. With block copolymers, a microstructure can be formed that is locally liquid-like (allowing high ionic conductivity), but globally solid-like (giving the material mechanical rigidity). To design a novel cathode intercalation oxide, the group will use first-principles calculations to determine the factors that influence the phase stability of the intercalation oxide.
Participating faculty and departmental affiliations: G. Ceder, Y.-M. Chiang, A. Mayes and D. Sadoway (Materials Science and Engineering).
This group will focus on creating and understanding these materials for the design of new classes of chemical sensors, actuators, and catalysts. Approaches to molecular recognition will include the organization of diverse functionality in the heteropolymer gels and the integration of preorganized receptor units. For catalysis, recognition sites must be developed which stabilize reactive intermediates, thereby lowering the activation energies of specific chemical reactions. In all cases, molecular recognition requires that the gel exhibit a specific global thermodynamic minimum in the polymer’s conformation similar to those exhibited by enzymes. Strategies for imprinting such a global minimum in a polymer gel will be developed utilizing cross-links based on disulfide linkages and novel physical cross-links resulting from threading of a second polymer through macrocyclic linkages. The recognition properties of the gels enable chemo-activated mechanical responses. Gel actuators based upon volume transitions will also be pursued.
Participating faculty and departmental affiliations: T. Swager (Chemistry); S.B. Leeb (Electrical Engineering and Computer Science); and A.N. Berker, and T. Tanaka (Physics).
The center funded the following seed grants during the 1999—2000 year. The participating faculty and departmental affiliations follow the project title.
During the course of the year, the seed research of Karen Gleason was incorporated into the IRG on Microstructure and Mechanical Performance of Polymeric Materials.
CMSE collaborates with other laboratories and centers at MIT that carry out materials-related research and engineering with direct involvement of industry and other sectors, and CMSE facilities are modified in coordination with these organizations to assure that the overall spectrum of facilities offered by MIT is as broad as possible without unnecessary redundancy.
The SEFs are a critical feature of CMSE’s collaborations with non-MIT personnel. The facilities are made available to any researcher from a nonprofit institution and to industrial researchers when equivalent facilities are not available commercially. During the past year, CMSE facilities have been utilized by 13 commercial organizations and 16 outside academic institutions. The CMSE/IBM X-ray participating research team (PRT) at the National Synchrotron Light Source (NSLS) at Brookhaven and the CMSE/Whitehead Institute/IBM/McGill (CAT) under development at the Argonne Advanced Photon Source (APS) are very special facilities constructed and operated with direct industrial and government laboratory collaboration. These PRTs and the neutron diffraction PRT at the National Institute of Standards and Technology (NIST) provide users from all sectors with access to those facilities. Finally, several of the IRGs participate in direct research collaboration with industry and other sectors. This is important for exchange of knowledge and the education of graduate students, for it provides them with direct experience of industrial research.
CMSE’s programs contribute to the education of both undergraduate and graduate students in a variety of ways. Joint programs with the Materials Processing Center (MPC) and the Office of Graduate Education bring undergraduates from all across the nation to MIT in the summer to become involved in materials research. The SEFs are also important in undergraduate education. Courses, such as those in X-ray scattering and electron microscopy, teach students to use processing and characterization facilities and to carry out research projects using the equipment. A course entitled Materials Synthesis and Processing, taught by the Department of Materials Science and Engineering and initiated with partial NSF support, uses the SEFs extensively. In addition, short courses are taught using the facilities during the Independent Activities Period. At the graduate level, CMSE plays a critical role in the education of almost all the students at MIT who do materials-related research. The CMSE colloquium series provides an opportunity for graduate students from many departments to learn about the broad range of research activities. In addition to students directly involved in the research of the IRGs, the shared facilities are used by graduate students from 11 academic departments.
CMSE is committed to providing opportunities to women and minorities through hiring and educational and research programs. During the past year, one female senior staff assistant left the CMSE headquarters staff. Other staff changes included the addition of a male postdoctoral associate and the departure of a male research affiliate.
Of the seventeen students who participated in the CMSE Undergraduate Research Opportunities Program, funded by the National Science Foundation as part of the MRSEC Program, five are women and twelve are men. Two of the UROP students are African-Americans.
The center offers three different programs that bring researchers to MIT during the summer. For the seventh year, CMSE and the MPC jointly sponsor a ten-week internship program. Ten interns were selected from applications submitted by approximately 150 undergraduates from other universities around the country. Five of these scholars are women, and one is a Pacific Islander. The interns include Rebecca Boudreaux (University of Southern Mississippi), Hsin Chiang (University of Illinois at Urbana-Champaign), Stephanie Connor (Iowa State University), Adrian Fehr (University of Washington), Meghan Kerner (Case Western Reserve University), Adam Nolte (University of Missouri-Rolla), Bradley Peterson (University of Maryland Baltimore County), Nicole Seiberlich (Yale University), George Tripp (Utah State University), and Patrick Underhill (Washington University). CMSE also sponsors two Hispanic undergraduates participating in the Graduate Education Office’s MIT Summer Research Program. Both José Méndez-del Rio and Miguel Angel Vescovacci are students at the University of Puerto Rico-Mayaguez. The third program, Materials Research Experience for Teachers, brings three science teachers to campus for seven weeks to work with MRSEC faculty members and their research groups. Lori Robb and Edward Rice are seventh- and eighth-grade science teachers in Cambridge public schools, and Sean Müller teaches chemistry at Merrimack High School in New Hampshire.
For the eighth year, the center operated its successful science and engineering day camp for seventh- and eighth-grade students, most of whom are members of underrepresented minority groups. During the summer of 1999, the program hosted 17 students from two Cambridge public schools. The students included fourteen who are members of underrepresented minority groups. Thirteen of the students are girls and four are boys. The students were supervised by volunteer faculty and staff, as well as MIT undergraduates Van Kennedy Clary, Patricia Diaz, Hsingching Hsu, Amy Lin, Rafael Mandujano, and Autumn Zhang.
We continued the CMSE graduate minority research assistant (RA) program to support the development of doctoral-level scientists and engineers in the field of materials. During the 1999—2000 academic year, the center provided RA support to two male graduate students who are members of underrepresented minority groups, one in the Department of Electrical Engineering and Computer Science and one in the Department of Mechanical Engineering. In addition, seed funding was granted to one minority female faculty member working in the field of materials science and engineering.
More information about the Center for Materials Science and Engineering can be found on the World Wide Web at http://web.mit.edu/cmse/www/.
Robert J. Silbey
MIT Reports to the President 1999–2000