An Assessment of the National Institute of Standards and Technology Materials Science and Engineering Laboratory: Fiscal Year 2008 (2008)

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Polymers Division SUMMARY The Polymers Division has done outstanding work with an energetic and highly motivated group focused on customers and collaborations to achieve its objective of providing critical measurement solutions with a high impact. In addition, the division has done exceptionally well in executing several projects in areas of critical importance to industry (electronic materials, biomaterials, and industrial polymers), homeland security (passport security with the U.S. Department of State and the U.S. Government Printing Office), the U.S. Department of Justice (body armor), consortia (SEMATECH, the Semiconductor Research Consortium, and others), and academia. The division has been very proactive in engaging faculty and graduate students in its research portfolio and in attracting them in large numbers through the NRC-NIST postdoctoral fellowships. This has proven to be a very effective recruiting mechanism. Energy is a significant contemporary problem; NIST in general and the Polymers Division in particular can make important contributions to the measurement science and technology related to organic photovoltaics (OPVs) and energy storage devices. Efforts in this area are slightly below an effective critical mass and should be increased if the Polymers Division is to have significant impact in this area. The presentations to the panel did not indicate how the recommendations of previous NRC panels have been addressed, and for many of the programs presented, a plan for the future was not clearly laid out. For example, it is not clear how the Matrix-Assisted Laser Desorption Ionization (MALDI) program has been reoriented to address the previous panel’s comment that “the work in the laboratory on mass spectrometry . . . (MALDI-mass spectrometry) of polymers has been very relevant. It is now time to consider whether the ‘low-hanging fruit has been picked.’ The laboratory may wish to consider whether the most effective use of resources is to continue these programs at their current levels.”10 Even presentations showing breakthrough results did not clearly articulate a vision for the future. TECHNICAL MERIT RELATIVE TO STATE OF THE ART The polymer projects in all six of the Polymers Division’s groups demonstrate outstanding technical performance in most areas, with examples of state-of-the-art accomplishments, and strike a good balance between exploring the frontiers of measurement science and technology and in transferring the know-how to U.S. industry for economic impact, strengthening U.S. competitiveness. The researchers have been publishing papers in journals, presenting at workshops, and giving invited presentations to conferences, industry, and academia. They also have received several noteworthy awards, including the Presidential Early Career Award for Scientists and Engineers, American Chemical Society fellow, and NIMS young scientist awards. The division’s programs are highly leveraged with cooperative research and development agreements, or CRADAs (e.g., the Electronics Materials CRADA with Intel Corporation), 10 National Research Council, 2005, An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Years 2004-2005, Washington, D.C.: The National Academies Press, p. 75. 19 

interagency agreements (e.g., Biomaterials NIH Research Project Grants [R01s], Exploratory/Developmental Grants [R21s], National Institute of Dental and Craniofacial Research/NIH grants), visitors, sabbaticals (e.g., Intel, IBM, Seoul National University), and synergistic collaborations (e.g., SEMATECH in electronics materials). NIST-developed measurement methods can have far-reaching consequences in transforming U.S. industries and competitiveness. The Polymers Division should more aggressively cultivate relationships with analytical equipment companies, both as customers and collaborators, in order to define an easy path for technology to reach the marketplace. ADEQUACY OF INFRASTRUCTURE This division of 106 people with a budget of $14 million is pursuing 22 projects with a great deal of success. However, given the resources available, the division should either obtain additional resources or consider deemphasizing programs that require substantially more resources in order to offer a reasonable probability of success. A return on investment and/or impact assessment should be done, investment should be made, and resources should be placed in those areas where a significant impact can be made realistically. The fuel cell effort is an example. While this problem is important, it is a complex problem that requires a significant investment of personnel and other resources. The level of effort currently underway is insufficient to have substantial impact. This is not a criticism of the technical level of the current effort, but rather a realistic assessment of the potential outcomes. Either more investment needs to be made or the efforts of the program should be redirected elsewhere. The depth and breadth of the staff are impressive, as is the division’s continuing ability to attract high-quality staff, associates, and postdoctoral fellows. The objectives and the vision for building a diverse workforce will be challenging in the absence of significant hiring. Several group leaders are serving also as principal investigators for projects. While these leaders seem to be doing an effective job of carrying out both leadership and technical functions, this may not prove to be an effective long-term strategy. There was not apparent within the division a sufficient computational materials science effort to complement the outstanding experimental accomplishments. In several areas, theory and simulations to interpret the experimental measurements could likely provide additional predictive power. Hiring a knowledgeable senior computational scientist or NRC postdoctoral fellows with theoretical expertise may be an effective way to initiate an effort in this direction. ACHIEVEMENT OF OBJECTIVES AND IMPACT Electronic Materials Group The Electronic Materials Group has done an outstanding job of developing measurement methods for the use of polymeric materials for the electronics industry. The group has extensively collaborated with major industrial customers (Intel, IBM, and Advanced Micro Devices), consortia (e.g., SEMATECH), and academia. The effort is currently targeting opportunities to develop similar methods for emerging electronics areas (flexible electronics, OPVs, and energy). Its efforts in dimensional metrology with Intel and other collaborators using critical-dimension small-angle x-ray scattering (CD-SAXS) can complement, validate, and augment existing destructive and nondestructive pattern shape measurement technologies. 20 

The high-quality, important, fundamental studies on understanding the materials sources of line-edge roughness are of significance in driving the electronics industry down Moore’s curve. An example is the development of measurement methods delineating the rheological basis for residual stress in patterns printed by nanoimprint lithography. It is important to apply this technology for sub-25 nm CMOS and non-CMOS patterning applications. The integrated suite of measurement capabilities, including x-ray techniques coupled with spectroscopy, serves as an example of how this group has been able to illustrate the importance of conjugated plane tilt and side chain interdigitation in explaining the serendipitous observation of high conductivity in pBTTT (poly(2.5-bis(3-quaterdecylthiophene-2-yl)- thieno[3.2-b]thiophene), a thiophene-based copolymer. Nanostructured Materials Group The Nanostructured Materials Group has 14 people working on a large number of projects that do not seem to be related. For example, the templated assembly of block copolymers, fate of nanoparticles in biological systems, and fuel cell membrane efforts have little in common. Nevertheless the projects, such as the block copolymers work, appear to be well thought out and tightly coupled with industry and likely to have a broad impact. The measurement methods developed for gold and titanium dioxide nanoparticles and their aggregation and characteristics in biological systems are rigorous. Processing Characterization Group The 19 people in the Processing Characterization Group focus on nanotube metrology, directed assembly, and microrheometry. In the area of microrheometry, significant resources are to be deployed in the future in addressing measurement needs of complex fluids with rheology, spectroscopy, microscopy, and microfluidics. The Nanotube Metrology Program is outstanding and has made noteworthy progress since 3 years ago when demonstrated concepts during the previous NRC assessment were only at the idea stage. The integrated approach employing key techniques in dispersion, separation, and standards development with nanotubes is an example of the depth and breadth that this group brings to bear on addressing important measurement problems. Biomaterials Group The Biomaterials Group has made impressive progress in the past 3 years. The project on dental materials has been well refocused and reorganized to be of high impact by concentrating on improving the understanding of the fundamentals of composite shrinkage, stress development, tooth and composite interphase, and interphase stability under bacterial challenge in order to develop clinically relevant information related to shrinkage and microleakage. There is an opportunity for this group to find a pathway for biomarker materials to become available to U.S. industry and academia, as they can have a high impact on biomedical research. The Quantum Dot Program is exemplary in this regard in terms of quality of work. The Protein Preservation project systematically examined the relationship between material properties and protein stability using a model system and found that there is a correlation between local glass dynamics and protein stability in glass. This group has 21 

developed a benchtop surrogate for neutron backscattering using steady-state fluorescence techniques. The major emerging industry in regenerative medicine will continue to raise multifactorial problems in materials science. There will be a growing and continuing need for standards and metrology that address the needs of this industry, with NIST uniquely positioned to play a large role. Progress is being made in this regard and, in particular, there has been close cooperation with ASTM to provide leadership in the development of reference scaffolds for tissue engineering. Characterization and Measurement Group The Characterization and Measurement Group has enjoyed great success in its Machine- Readable Travel Documents project, in which it tackled an important problem for the U.S. Department of State and carried it out remarkably well. This group has the capabilities needed to address challenging technical problems quickly and well. The group is performing a study of the ballistic resistance of polymeric materials by examining compromised body armor. The results obtained using a folding test apparatus designed by the group motivated the U.S. Department of Justice’s National Institute of Justice to include folding protocols in the draft of its current ballistic armor standard. The group should pursue opportunities for beneficial follow-on projects. The project on Thermal Properties at the Nanoscale has developed new measurement techniques for nanothermomechanometry. One application to carbon fullerenes (C60) was mentioned to the panel. It has promising potential for other applications. Combinatorial Methods Group The Combinatorial Methods Group has done an outstanding job of retaining the best of an open-source consortium model while expanding the underlying core strengths of the group to probe complex interfaces and thin films. The group has accomplished impressive developments of a library of microfluidic surface-initiated grafted copolymers with systematic gradients in chemistry, architecture, and molecular weight. It has also developed an impressive microfluidic technique to determine copolymer reactivity ratios. CONCLUSIONS The Polymers Division is doing an effective job in building an outstanding research team. The team is talented, energetic, and motivated to have an impact on polymer measurement science and technology. The division should review its programs to ensure a critical mass per program by either providing more resources or trimming the number of programs. Building some computational work is important to complement the outstanding experimental accomplishments. In several areas, theory and simulations to interpret the experimental measurements could likely provide additional predictive power. Energy is a significant contemporary problem, and NIST in general and the Polymers Division specifically can make important contributions to the measurement science and technology related to OPVs and energy storage devices. 22