bluuebunny/crossref_metadata_2025_split huggingface dataset:
Science and Technology of Shape-Memory Alloys: New Developments
Authors: Otsuka Kazuhiro , Kakeshita Tomoyuki 
Published: February 2011

AbstractThe martensitic (also called displacive or diffusionless) transformation is a classical cooperative phenomenon in solids similar to ferromagnetism. Although the displacement of each atom is not large, the transformation results in a macroscopic change in shape, since all of the atoms move in the same direction in a domain or variant. As a result, unique properties arise, such as the shape-memory effect and superelasticity, whose characteristics are quite distinct from those of normal metals and alloys. Because of these unique properties, shape-memory alloys (SMAs) have been used as new functional materials for applications such as couplings, sensors, actuators, and antennas for cellular phones. In this issue of MRS Bulletin, we present an overview of recent progress in this field. In this introductory article, we discuss fundamental notions, such as the mechanism of the shape-memory effect, the martensitic transformation, and superelasticity, along with examples of applications and other important recent topics not treated in the following articles. It will be shown that progress in the science and technology of shape-memory alloys has been achieved by the side-by-side development of fundamentals and applications.
Sputter-Deposited Shape-Memory Alloy Thin Films: Properties and Applications
Authors: Ishida Akira , Martynov Valery 
Published: February 2011

AbstractShape-memory alloy (SMA) thin films formed by sputter deposition have attracted considerable attention in the last decade. Current intensive research demonstrates that unique fine microstructures are responsible for the superior shape-memory characteristics observed in thin films as compared with bulk materials. Simultaneously, much effort has been undertaken to develop and fabricate micro devices actuated by SMA thin films. This article reviews the research to date on shape-memory behavior and the mechanical properties of SMA thin films in connection with their peculiar microstructures. Promising applications such as microvalves are demonstrated, along with a focused discussion on process-related problems. All of the results indicate that thin-film shape-memory actuators are ready to contribute to the development of microelectromechanical systems.
The Interaction of Point Defects with the Martensitic Transformation: A Prototype of Exotic Multiscale Phenomena
Authors: Ren Xiaobing , Otsuka Kazuhiro 
Published: February 2011

AbstractThe martensitic transformation has so far been studied without considering its interaction with point defects. In this article, we shall show that such interaction, which stems from a universal symmetry property of point defects, can create a rich spectrum of exotic multiscale phenomena in martensitic materials. These phenomena include unique short-range diffusion at the atomic or nano level, remarkable domain-pattern memory at the mesoscopic level, and peculiar rubber-like behavior and aging-induced two-way shape memory at the macroscopic level. Exotic multiscale phenomena may also be found in a wide range of transforming materials, such as ferroelastic, ferroelectric, and ferromagnetic materials. These novel effects may provide new opportunities for these important materials.
On the Electrical Characterization of High-ĸ Dielectrics
Authors: Degraeve R. , Cartier E. , Kauerauf T. , Carter R. , Pantisano L. , Kerber A. , Groeseneken G. 
Published: February 2011

AbstractThe continual scaling of complementary metal oxide semiconductor (CMOS) technologies has pushed the Si-SiO2 system to its very limits and has led to the consideration of a number of alternative high-ĸ gate dielectric materials. In the end, it will be the electrical properties of the new Si/high-ĸ system that will determine its usefulness in future CMOS generations. For this reason, the study of the electrical properties of high-ĸ gate insulators is crucial. We present an overview of some of the electrical characterization techniques and reliability tests used to evaluate possible high-ĸ gate materials. Most of these techniques are well known from the characterization of SiO2 layers, but there are some additional complications, such as the presence of several different layers within one gate stack or the use of different gate electrode materials. These make the interpretation and comparison of experimental results more troublesome.
Combinatorial Materials Science: What's New Since Edison?
Authors: Amis Eric J. , Xiang Xiao-Dong , Zhao Ji-Cheng 
Published: February 2011

AbstractCombinatorial methods are high-efficiency methods to create large composition “libraries” of materials, for example, continuous composition variations, and test those compositions systematically in parallel for specific properties of interest, in contrast to the time-consuming one-composition-at-a-time approach. These methods have captured the attention of the materials industry with the promise of providing new discoveries “faster, better, and cheaper.” However, in the academic community, combinatorial methods often meet with less enthusiasm, perhaps due to the perception of combinatorial methodology as an Edisonian approach to science. The facts are quite to the contrary. In addition to impressive successes arising from the application of combinatorial methods to materials discovery, results coming out of systematic high-throughput investigations of complex materials phenomena (which would be too time-consuming or expensive to undertake) provide data leading to improvement in theories and models of materials chemistry and physics. Indeed, combinatorial methods provide a new paradigm for advancing a central scientific goal—the fundamental understanding of structure–property relationships of materials behavior.
Organic Materials for Photonic Devices
Authors: Fuhrmann Thomas , Salbeck Josef 
Published: February 2011

AbstractCurrent issues in the development of organic materials for photonic applications are reviewed. Organic light-emitting diodes, which are a main focus of industrial research at the moment, are given special emphasis. Other applications in optical communications technology, including organic solid-state lasers, optical switching devices, and data storage, are also covered.
Designing Soft Reactive Adhesives by Controlling Polymer Chemistry
Authors: Aymonier Agnès , Papon Eric 
Published: February 2011

AbstractSoft reactive adhesives (SRAs) are polymer-based materials (e.g., polyurethanes, polysiloxanes, polydienes) designed to be further vulcanized or slightly cross-linked through external activation (heat, moisture, oxygen, UV–visible irradiation, etc.), either at the time of their application or within a subsequent predefined period. They are used mainly as mastics, or sealing compounds, in a wide range of industrial and commercial fields such as construction, footwear, and the automotive industry. Generally deposited as thick films, SRAs behave as structural adhesives; their low elastic moduli accommodate large strains between the bonded parts without incurring permanent damage. Other outstanding attributes of SRAs are their resistance to solvents, their ability to withstand aggressive environments, and their ease of use. This article discusses examples of SRAs and, more specifically, shows how the cross-linking chemistry, mainly through step-growth polymerization, provides their primary advantages.
Hot-Melt Adhesives
Authors: Paul C. W. 
Published: February 2011

AbstractHot-melt adhesives facilitate fast production processes because the adhesives set simply by cooling. Formulations contain polymers to provide strength and hot tack (resistance to separation while adhesive is hot), and tackifiers and/or oils to dilute the polymer entanglement network, adjust the glass-transition temperature, lower the viscosity, and improve wet-out (molecular contact of the adhesive with the substrate over the entire bonding area). Some adhesives also contain waxes to speed setting, lower viscosity, and improve heat resistance. Obtaining adequate strength and heat resistance from nonreactive hot melts requires that some component of the hot melt separate out into a dispersed but interconnected hard-phase network upon cooling. The hard phases are commonly either glassy styrene domains (for adhesives based on styrenic block copolymers) or organic crystallites (for adhesives based on waxes, olefinic copolymers, or ethylene copolymers). This article will describe first the material properties relevant to the processing and performance of hot-melt adhesives, then the chemistry and function of the specific raw materials used in hot melts, and will conclude with illustrative application examples and corresponding formulations.
Critical Aspects of High-Performance Microprocessor Packaging
Authors: Atluri Vasudeva P. , Mahajan Ravi V. , Patel Priyavadan R. , Mallik Debendra , Tang John , Wakharkar Vijay S. , Chrysler Gregory M. , Chiu Chia-Pin , Choksi Gaurang N. , Viswanath Ram S. 
Published: February 2011

AbstractHistorically, the primary function of microprocessor packaging has been to facilitate electrical connectivity of the complex and intricate silicon microprocessor chips to the printed circuit board while providing protection to the chips from the external environment. However, as microprocessor performance continues to follow Moore's law, the package has evolved from a simple protective enclosure to a key enabler of performance. The art and science of semiconductor packaging has advanced radically over the past few decades as faster and more powerful microprocessors with tens of millions of transistors continue to be available, which require more signal and power input/output connections as well as greater power-dissipation capabilities. Key drivers for the development of packaging technologies include power delivery, thermal management, and interconnect scaling, in which the space transformation from fine-featured silicon interconnects to the relatively coarse features seen on motherboards has to be enabled by the package. These drivers, under constant market-driven cost pressure, have led to increased demands on new materials and new package architectures to enable silicon performance. Significant advances have already been made in the areas of heat dissipation, power delivery, high-speed signaling, and high-density interconnects. It is expected that the future evolution of microprocessors will be increasingly challenging in these areas. This article focuses on providing a broad perspective view of the evolution of microprocessor packaging and discusses future challenges.
Materials for 3D Packaging of Electronic and Optoelectronic Systems
Authors: Ozguz Volkan H. , Yamaguchi James 
Published: February 2011

AbstractAdvanced three-dimensional (3D) packaging techniques for electronic components are promising for the realization of “systems-in-packages.” Three-dimensional packages require the use of a variety of materials within a small physical size range. Materials selection is therefore critical from electrical, optical, mechanical, structural, thermal, and manufacturability viewpoints. The materials combination depends also on the intended application for the 3D packaged modules. This article reviews 3D packaging approaches, materials classes, and examples. Three-dimensional packaged systems using judiciously selected materials offer performance advantages that cannot be provided by planar implementation.
Packaging Options for MEMS Devices
Authors: Jung Erik 
Published: February 2011

AbstractMicroelectromechanical systems (MEMS) devices can be delicate structures sensitive to damage from handling or environmental influences. Their functionality may furthermore depend on sealing out the environment or being in direct contact with it. Stress, thermal load, and contaminants may change their characteristics. Here, packaging technology is challenged to extend from microelectronics toward MEMS and optoelectronic MEMS (MOEMS). Today's approaches rely on modified single-chip packages derived from the microelectronics industry, wafer-level capping to enable the device to be packaged like an integrated circuit, or highly specialized packages designed to complement the function of the MEMS device itself. Selecting the proper packaging method may tip the scale toward a product success or a product failure. Choosing the right technology, therefore, is a crucial part of the product design.
Smart Textiles: Wearable Electronic Systems
Authors: Park Sungmee , Jayaraman Sundaresan 
Published: February 2011

AbstractProtection and aesthetics are the two common dimensions or attributes typically associated with textiles as clothing. However, with the rapidly changing needs of today's consumers, a third dimension is emerging—that of “intelligence”—that is being integrated into fabrics to produce interactive textiles, or i-textiles. This new class of wearable electronic systems is being designed to meet new and innovative applications in the military, public safety, healthcare, space exploration, sports, and consumer fitness fields. In this article, the concept of i-textiles is presented, along with the building blocks for its realization. This is followed by an overview of the design and development of the Smart Shirt, an “intelligent” garment that provides an extremely versatile framework for the incorporation of sensing, monitoring, and information-processing devices. The key applications of the Smart Shirt technology and their impact in transforming healthcare are discussed. Finally, the need to advance this paradigm and identify opportunities to transform passive textiles into the new generation of interactive, or “smart,” textiles is discussed.
Concepts for Energy-Interactive Textiles
Authors: Kim Yong K. , Lewis Armand F. 
Published: February 2011

AbstractThis review examines textile fibers and fabrics in the context of their interaction with various forms of energy, such as electromagnetic (photolytic), electrical, magnetic, thermal, chemical, and mechanical. This interaction can involve conversion, storage, or management of energy. Examples are described suggesting some new material configurations that could be incorporated into textiles to create special energy-interactive textile (EITX) structures. Areas discussed are the management of electron flow (electrical resistivity) and the absorption of mechanical energy in textile fibers and fabrics. Surface resistance studies on carbon nanotubes and conductive carbon-black-filled films of poly(methyl methacrylate) (PMMA) and paraffin wax show that the electrical conductivity of these materials depends upon the matrix material type and the amount of charge-carrying particles in the matrix. PMMA films filled with carbon nanotubes are found to be more electrically conductive than matrices filled with conductive carbon black. Mechanical-energy interactions of flocked textile surfaces show that in compression, they exhibit unique, gradual load-deflection behavior. This effect should be useful in applications requiring impact-energy absorption. Finally, the functional steps in an integrated energy-interactive textile system are discussed.
Ultrahigh-Temperature Materials for Jet Engines
Authors: Zhao J.-C. , Westbrook J. H. 
Published: February 2011

AbstractThis introductory article provides the background for the September 2003 issue ofMRS Bulletinon Ultrahigh-Temperature Materials for Jet Engines. It covers the need for these materials, the history of their development, and current challenges driving continued research and development. The individual articles that follow review achievements in four different material classes (threein situcomposites—based on molybdenum silicide, niobium silicide, and silicon carbide, respectively—and high-melting-point platinum-group-metal alloys), as well as advances in coating systems developed both for oxidation protection and as thermal barriers. The articles serve as a benchmark to illustrate the progress made to date and the challenges ahead for ultrahigh-temperature jet-engine materials.
Chip-to-Module Interconnections Using “Sea of Leads” Technology
Authors: Bakir Muhannad S. , Reed Hollie A. , Mulé Anthony V. , Jayachandran Joseph Paul , Kohl Paul A. , Martin Kevin P. , Gaylord Thomas K. , Meindl James D. 
Published: February 2011

AbstractThe drive toward higher density and higher performance in integrated circuits creates a need to keep interconnects short and eliminate layers of packaging. In this article, we propose a novel, ultrahigh-density (exceeding 104leads per cm2), compliant, wafer-level, input/output interconnection technology called “sea of leads” as a key enabling technology for future high-performance microsystems. The mechanical compliance is addressed through slippery leads (leads released from the surface) and embedded air gaps. The ability to fabricate embedded air gaps has enabled the integration of optical interconnects with high index-of-refraction mismatches between the core and cladding.
Development of Platinum-Group-Metal Superalloys for High-Temperature Use
Authors: Cornish L. A. , Fischer B. , Völkl R. 
Published: February 2011

AbstractSuperalloys based on platinum-group metals are being developed for high-temperature applications. These alloys have two-phase structures comprising either ordered precipitates in a matrix analogous to the nickel-based superalloys or a fine dispersion of oxide particles in a matrix analogous to oxide-dispersion-strengthened nickel-based alloys. Currently, alloys based on iridium, rhodium, and platinum have been obtained. This article reviews the rationale of developments and the progress made in this area. Oxidation and compression tests as well as characterization with scanning electron microscopy and transmission electron microscopy were undertaken. These tests showed encouraging results, and further work is being done on new alloying additions and tensile testing.
Emerging Materials Challenges in Microelectronics Packaging
Authors: Frear D. R. , Thomas S. 
Published: February 2011

IntroductionThe trend for microelectronic devices has historically been, and will continue to be, toward a smaller feature size, faster speeds, more complexity, higher power, and lower cost. The driving force behind these advances has traditionally been microprocessors. With the tremendous growth of wireless telecommunications, rf applications are beginning to drive many areas of microelectronics that traditionally were led by developments in microprocessors. An increasingly dominant factor in rf microelectronics is electronic packaging, and the materials needed to create the package, because the package materials strongly affect the performance of the electronics. Many challenges remain for the packaging of microprocessors as well. These challenges include increased speed, the number of input/output interconnects, decreased pitch, and decreased cost. This article highlights the key issues facing the packaging of high-performance digital and rf electronics.
New Possibilities for Ferromagnetic Semiconductors
Authors: Chambers Scott A. , Farrow Robin F.C. 
Published: February 2011

AbstractNew candidate ferromagnetic semiconductors have recently been grown by doping semiconducting transition-metal oxides with magnetic impurities. Some of these exhibit ferromagnetism at and above room temperature. The critical question is why? In many cases, complex solid-state chemistry is involved in the synthesis and drives the resulting properties. The observation of room-temperature ferromagnetism in these materials must be accompanied by a careful identification of the phases and structures present in order to accurately identify the origin of the magnetism.
Combinatorial Investigation of Spintronic Materials
Authors: Matsumoto Y. , Koinuma H. , Hasegawa T. , Takeuchi I. , Tsui F. , Yoo Young K. 
Published: February 2011

AbstractHigh-throughput synthesis and characterization techniques have been effective in discovering new materials and performing rapid mapping of phase diagrams. The application of the combinatorial strategy to explore doped transition-metal oxides has led to the discovery of a transparent room-temperature ferromagnetic oxide in Co-doped anatase TiO2. The discovery has triggered a wave of studies into other metal oxide systems in pursuit of diluted magnetic semiconductors. In this article, we describe recent combinatorial studies of magnetic transition-metal oxides, germanium-based magnetic semiconductors, and Heusler alloys.
Drop-on-Demand Printing of Protein Biochip Arrays
Authors: Zaugg Frank G. , Wagner Peter 
Published: February 2011

AbstractProtein biochips have recently gained a lot of attention as bioanalytical tools in the life sciences. The creation of such biochips has been made possible by the integration of scientific approaches and methodologies in microfabrication, organic interface chemistry, protein engineering, detection physics, and—last but not least—advances in microarrays and microfluidic dispensing technologies. This article reviews some of the current drop-on-demand technologies developed for printing biomolecular arrays, with an emphasis on proteins and the technical challenges associated with them.
Applications of Neutron Reflectivity Measurements to Nanoscience: Thin Films and Interfaces
Authors: Ankner John F. , Zabel Hartmut 
Published: February 2011

AbstractNeutron reflectivity has matured in recent years from an exotic method used only by a few experts to an essential tool for the investigation of thin films and interfaces on the nanoscale. In contrast to x-ray reflectivity, which provides electron density profiles, neutron reflectivity reveals the nuclear density profile. This is an essential difference when exploring hydrogenous materials such as polymers, Langmuir–Blodgett films, and membranes. Furthermore, neutrons carry a magnetic moment that interacts with the magnetic induction of the film, revealing, in addition to the nuclear density profile, the magnetic density profile in layers and superlattices. Recent developments in the analysis of off-specular neutron reflectivity data enable the characterization of chemical and magnetic correlations within the film plane on nanometer to micron length scales. A new generation of pulsed neutron sources, featuring flux enhancements of factors of 10–100 over existing sources, will make these types of measurements even more exciting, while kinetic studies, pump-probe, and small-sample experiments will become feasible, opening new windows onto nanoscale materials science.
Single-Event Upsets in Microelectronics
Authors: Tang Henry H.K. , Olsson Nils 
Published: February 2011

AbstractThis article introduces the February 2003 issue of MRS Bulletin on “Single-Event Upsets (SEUs) in Microelectronics.” These radiation effects in devices and circuits have been recognized in recent years as a key reliability concern for many current and future silicon-based technologies. This introduction sets the scope for critical discussions on this subject. The articles in the issue reflect the interdisciplinary nature of SEU research. The contributing authors include experts from several specializations: technology reliability, materials science, device physics, circuit designs, and theoretical and experimental nuclear physics. We review the current understanding of SEU problems from the perspectives of radiation physics, circuit design issues, and global technology developments. The discussions cover the key areas of modeling, circuit analyses, accelerator tests and experiments, basic nuclear data, and environmental neutron measurements.