bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conjugated-Polymer Micro- and Milliactuators for Biological Applications
Authors: Immerstrand C. , Holmgren-Peterson K. , Magnusson K.-E. , Jager E. , Krogh M. , Skoglund M. , Selbing A. , Inganäs O. 
Published: February 2011

AbstractThe development of new conjugated-polymer tools for the study of the biological realm, and for use in a clinical setting, is reviewed in this article. Conjugated-polymer actuators, based on the changes of volume of the active conjugated polymer during redox transformation, can be used in electrolytes employed in cell-culture media and in biological fluids such as blood, plasma, and urine. Actuators ranging in size from 10 μm to 100 μm suitable for building structures to manipulate single cells are produced with photolithographic techniques. Larger actuators may be used for the manipulation of blood vessels and biological tissue.
Blue and Near-Ultraviolet Vertical-Cavity Surface-Emitting Lasers
Authors: Nurmikko Arto , Han Jung 
Published: February 2011

AbstractVertical-cavity surface-emitting lasers (VCSELs) based on gallium nitride semiconductor heterostructures represent a contemporary focus of research, the aim of which is to develop a new class of planar microdevices in the blue, violet, and near-ultraviolet ranges. We review recent progress in this exploratory area, to highlight the challenges and scientific excitement associated with the efforts that are under way to create flexible, short-wavelength sources for applications expected to range from biomedical diagnostics to solid-state displays and lighting.
Vertical-Cavity Surface-Emitting Lasers: Light for the Information Age
Authors: Choquette Kent D. 
Published: February 2011

AbstractThe emergence of miniature light sources such as the vertical-cavity surface-emitting laser (VCSEL) is poised to advance the information age. The development of VCSELs has stimulated a wide range of materials research into epitaxial growth and device-fabrication technologies. In this article, current and emerging applications that are guiding the commercial development of VCSELs are first considered, followed by discussions of the VCSEL epitaxial structure and fabrication technologies. This brief overview will also mention recent efforts aimed at achieving long-wavelength VCSELs grown on GaAs substrates, as well as approaches for achieving a high modulation rate.
Infrared Vertical-Cavity Surface-Emitting Lasers: An Industrial Perspective
Authors: Kisker David W. , Bisberg Jeff E. 
Published: February 2011

AbstractOptical components based on vertical-cavity surface-emitting lasers (VCSELs) are moving from 850-nm wavelengths to 1.31-μm and 1.55-μm wavelengths. These long-wavelength devices, enabled by new developments in materials technology, will compete directly with distributed-feedback (DFB) and Fabry-Pérot (FP) laser technologies in fiber-optic markets. In addition, the unique properties of VCSELs are opening up a new category of optically integrated components that are not possible with traditional edge-emitting laser source technologies. These VCSEL structures, such as linear and two-dimensional arrays, have the potential to dramatically reduce the cost structure of traditional optical networking equipment and provide a path for rapid growth in optical bandwidth.
Dislocation Plasticity in Thin Metal Films
Authors: Kraft O. , Freund L. B. , Phillips R. , Arzt E. 
Published: February 2011

AbstractThis article describes the current level of understanding of dislocation plasticity in thin films and small structures in which the film or structure dimension plays an important role. Experimental observations of the deformation behavior of thin films, including mechanical testing as well as electron microscopy studies, will be discussed in light of theoretical models and dislocation simulations. In particular, the potential of applying strain-gradient plasticity theory to thin-film deformation is discussed. Although the results of all studies presented follow a “smaller is stronger” trend, a clear functional dependence has not yet been established.
Distributed Bragg Reflectors for Vertical-Cavity Surface-Emitting Lasers
Authors: Breiland W.G. , Allerman A.A. , Klem J.F. , Waldrip K.E. 
Published: February 2011

AbstractDistributed Bragg reflectors (DBRs) not only serve as high-reflectance mirrors to define the laser cavity of a vertical-cavity surface-emitting laser (VCSEL), but they also must conduct electricity, confine currents, and provide a single-crystal template for the gain region of the laser. Basic optical and electrical properties of DBRs are presented in this article. Three examples of DBR structures used in VCSEL applications from the ultraviolet to the infrared are given to illustrate the complexity and range of materials science issues that are encountered in DBR growth. Fabrication issues are also discussed.
Mechanisms Active during Fracture under Constraint
Authors: Cook Robert F. , Suo Z. 
Published: February 2011

AbstractMany advanced technologies center on devices of small feature sizes made of diverse materials. Internal stresses that arise in the devices during fabrication and use can result in fracture. Fracture of an individual feature in such a device may impair the function of the device. The materials surrounding the feature have a constraining effect on the elastic energy available to drive the fracture, the plastic flow associated with the fracture, and sometimes even the atomic processes at the crack tip. This article reviews fracture behavior in small structures, several distinct roles played by plasticity, and bond-breaking kinetics. Research challenges are alsooutlined.
Lithium Batteries for Biomedical Applications
Authors: Takeuchi Esther S. , Leising Randolph A. 
Published: February 2011

AbstractLithium batteries have been successfully used in implantable biomedical devices for the last 30 years, and in some cases the use of lithium power sources has significantly contributed to the viability of the device. These battery systems fall into two major categories: primary, or single-use, cells containing lithium-metal anodes; and secondary, or rechargeable, systems utilizing lithium-ion chemistry. Primary lithium batteries have been used for implantable devices such as cardiac pacemakers, drug pumps, neurostimulators, and cardiac defibrillators. Rechargeable batteries have been used with left ventricular assist devices and total artificial hearts. All of these cells share the characteristics of high safety, reliability, energy density, and predictability of performance. Additionally, state-of-charge indication and low self-discharge are important features, along with charging safety and high cycle life for rechargeable cells.
Issues in Energy Storage for Electric-Based Transportation
Authors: Nazri Gholam-Abbas 
Published: February 2011

AbstractThe key to market success for electric vehicles (EVs) has always been the energy-storage device, which limits driving range and vehicle acceleration. In many respects, rechargeable lithium batteries are the most attractive technology for storing energy and delivering it on demand in an automobile. Past and ongoing efforts to develop electric-based automotive propulsion systems are chronicled in this article.
Organic Materials Science
Authors: Whitesides George M. 
Published: February 2011

AbstractThe following article is based on the presentation given by George M. Whitesides, recipient of the 2000 MRS Von Hippel Award, the Materials Research Society's highest honor, at the 2000 MRS Fall Meeting in Boston on November 29, 2000. Whitesides was cited for “bringing fundamental concepts of organic chemistry and biology into materials science and engineering, through his pioneering research on surface modification, self-assembly, and soft lithography.” The article focuses on the growing role of organic chemistry in materials science. Historically, that role has been to provide organic polymers for use in structures, films, fibers, coatings, and so on. Organic chemistry is now emerging as a crucial part of three new areas in materials science. First, it provides materials with complex functionality. Second, it is the bridge between materials science and biology/medicine. Building an interface between biological systems and electronic or optical systems requires close attention to the molecular level of that interface. Third, organic chemistry provides a sophisticated synthetic entry into nanomaterials. Organic molecules are, in fact, exquisitely fabricated nanostructures, assembled with precision on the level of individual atoms. Colloids are a related set of nanostructures, and organic chemistry contributes importantly to their preparation as well.
Metallic Hydrides II: Materials for Electrochemical Storage
Authors: Joubert J.-M. , Latroche M. , Percheron-Guégan A. 
Published: February 2011

AbstractFor a century, nickel-cadmium (Ni-Cd) batteries have been widely used as electrochemical energy-storage cells. However, due to the rapid development of portable electronic devices and the increasing search for cleaner electric vehicles, new generations of batteries have been investigated during the last few decades. Among them, nickel metal hydride (Ni-MH) batteries, with their larger capacities and improved environmental compatibility, have shown their ability to replace Ni-Cd cells. The negative electrodes of Ni-MH batteries are made of reversibly hydride-forming intermetallic compounds. In this article, the crystallographic and thermodynamic properties of these compounds will be reviewed. Their hydrogen-absorption properties, their electrochemical performance, and the solutions that have been found to achieve reliable cycle life will be presented. The industrial market for Ni-MH batteries will also be discussed in comparison with other battery systems.
Metallic Hydrides III: Body-Centered-Cubic Solid-Solution Alloys
Authors: Akiba E. , Okada M. 
Published: February 2011

AbstractHydrogen-absorbing alloys with bcc (body-centered-cubic) structures, such as Ti-V-Mn, Ti-V-Cr, Ti-V-Cr-Mn, and Ti-Cr-(Mo, Ru), have been developed since 1993. These alloys have a higher hydrogen capacity (about 3.0 mass%) than conventional intermetallic hydrogen-absorbing alloys. Generally, bcc metals and alloys exhibit two plateaus in pressure–composition isotherms, but the lower plateau is far below atmospheric pressure at room temperature. Many efforts have been made to increase hydrogen capacity and raise the equilibrium pressure of this lower plateau. The crystal structure and morphology of Laves-phase-related bcc solid-solution alloys are reviewed.
Fundamentals of Slurry Design for CMP of Metal and Dielectric Materials
Authors: Singh Rajiv K. , Lee Seung-Mahn , Choi Kyu-Se , Bahar Basim G. , Choi Wonseop , Chen Zhan , Moudgil Brij M. 
Published: February 2011

AbstractThe formulation of slurries for chemical–mechanical planarization (CMP) is currently considered more of an art than a science, due to the lack of understanding of the wafer, slurry, and pad interactions involved. Several factors, including the large number of input variables for slurries and the synergistic interplay among input variables and output parameters, further complicate our ability to understand CMP phenomena. This article provides a fundamental basis for the choice of chemical additives and particles needed for present-day and next-generation slurry design. The effect of these components on nanoscale and microscale interaction phenomena is investigated. Methodologies are suggested for the development of next-generation slurries required to overcome CMP challenges related to defectivity and the surface topography of soft materials such as Low-κ dielectrics and copper.
Advances in Characterization of CMP Consumables
Authors: Moinpour Mansour , Tregub Alex , Oehler Andrea , Cadien Ken 
Published: February 2011

AbstractChemical–mechanical polishing, or planarization (CMP), has emerged as an increasingly important technology for integrated-circuit manufacturing. Consumables used during CMP interact in a complex manner with the polishing tool, the process conditions, and the wafer being polished. In this article, several advanced analytical methods are used to analyze the properties of slurries and pads under conditions similar to those found during CMP processing. Some of the key findings are that under these process conditions, pads can be stabilized with a heat treatment prior to installation on the polisher; pads absorb slurries at different rates, and slurries also react with the pads; and the mechanical properties of the pads are dependent on the orientation of the grooves on the pad. Dynamic rheometry was used to detect de-agglomeration in sheared slurries.
Development and Application of an Abrasive-Free Polishing Solution for Copper
Authors: Hanazono Masanobu , Amanokura Jin , Kamigata Yasuo 
Published: February 2011

AbstractAn abrasive-free polishing (AFP) solution for chemical–mechanical planarization (CMP) of copper films on semiconductor wafers has been developed to overcome such disadvantages of conventional CMP as dishing, erosion, Cu and oxide loss, and microscratching. Electrochemical methods are an effective way of understanding the role of each chemical component in the AFP solution in order to optimize its performance. Analysis of the reaction layer of Cu elucidates the reasons for the excellent results that have been obtained. By applying the AFP solution for Cu CMP in combination with a slurry for CMP of the metal barrier layer, seven-level multilayer Cu interconnections can be successfully fabricated.
Integration Challenges for CMP of Copper
Authors: Bajaj Rajeev , Zutshi Ajoy , Surana Rahul , Naik Mehul , Pan Tony 
Published: February 2011

AbstractAs the minimum feature size of microelectronic devices shrinks down to 130 nm, copper has been successfully adopted into logic applications.1–3 Copper requires damascene processing, which involves etching features into a dielectric substrate, filling the features with metal, and removing any excess metal. Therefore, chemical—mechanical planarization (CMP) is a key process in the final definition of the inlaid copper wires on a circuit. A second advance in the back-end processing of copper is the changing of the dielectric from SiO2 to a Low-κ material, which allows a thicker layer of dielectric to be used. Low-k dielectric films have much lower mechanical properties than SiO2; consequently, this poses new challenges in developing integration schemes.1,3–8
Advanced Flat-Panel Displays and Materials
Authors: Kuo Yue , Suzuki Kouji 
Published: February 2011

AbstractThis introductory article reviews the topics covered in this issue of MRS Bulletin on advanced flat-panel displays and materials. The common requirements of flat-panel displays are compact dimensions, low power consumption, light weight, and high performance. Flat-panel displays are incorporated in many consumer products as well as in a large range of industrial, medical, military, transportation-related, and scientific instruments. In recent years, there have been dramatic improvements in flat-panel display technology due to an enhanced understanding of various new or existing materials as well as fabrication processes. “Flat-panel display” is a general term that includes many different types of technologies. It includes panels that are in mass production, such as passive or active addressed liquid-crystal displays or plasma displays, and those in the early production or development stages, such as organic light-emitting devices or electrophoretic displays. It also includes novel products that are based on the principle of flat-panel display technology, such as solid-state x-ray imagers. The articles in this issue cover a range of these topics.
Improving Color Tracking in In-Plane Switching Mode Liquid-Crystal Displays
Authors: Utsumi Yuka , Komura Shinichi , Hiyama Ikuo , Tsumura Makoto , Kondo Katsumi 
Published: February 2011

AbstractColor tracking describes the ability of a display to faithfully reproduce the color quality of the source image. In liquid-crystal displays (LCDs), color tracking is dependent on brightness. In order to achieve high-performance color reproduction in LCDs, the accuracy of color tracking needs to be improved. By analyzing the characteristics of twisted-nematic (TN) and in-plane switching (IPS) modes of display, the cause of poor color tracking in each mode and the differences in their causes can be clarified. In TN mode displays, both chromaticity and brightness relate to the director configuration, that is, the directional alignment of the rod-like molecules of the liquid crystals, which varies with applied voltage. The ideal IPS LCD, by virtue of its operating principle, theoretically achieves perfect color tracking; however, in actual use, the color tracking is less than optimal due to twist deformation caused by the fixed directors on the alignment layer. Based on our analysis of these phenomena, we propose strategies for improving color tracking in IPS LCDs.
Low-Temperature Polycrystalline Silicon Thin-Film Transist or Technologies for System-on-Glass Displays
Authors: Uchikoga Shuichi 
Published: February 2011

AbstractThe elimination of conventional peripheral LSI (large-scale integration) drivers is considered essential to the development of future low-cost, energy-efficient, lightweight, and thin displays. System-on-glass (SOG) displays are a type of display with various functional circuits integrated on a glass substrate. Low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) make the integration of circuits possible because they can be assembled into complex, high-current driver circuits. Furthermore, LTPS TFTs are attracting attention for driving organic light-emitting devices (OLEDs). This article introduces present and future LTPS TFT technologies for SOG displays.
Solid-State X-Ray Imagers
Authors: Izumi Yoshihiro , Yamane Yasukuni 
Published: February 2011

AbstractNew solid-state x-ray imagers known as digital flat-panel x-ray detectors are about to be launched in the field of medical diagnostics. The combination of active-matrix technologies developed for active-matrix liquid-crystal displays and x-ray detection materials constitutes the basis of the detectors. Recently, two kinds of direct-conversion detectors have been developed in order to improve their performance. One is a detector using a thick x-ray photoconductor (∼1 mm) made of amorphous selenium, and the other is a novel hybrid panel detector using an x-ray photoconductor made of polycrystalline Cd(Zn)Te. As a result, excellent resolution and good linear sensitivity have been achieved. These detectors have great promise as next-generation digital imaging systems for fluoroscopy and radiography.
Paperlike Microencapsulated Electrophoretic Materials and Displays
Authors: Kazlas Peter T. , McCreary Michael D. 
Published: February 2011

AbstractMicroencapsulated electrophoretic (MEP) materials exhibit high optical reflectance and contrast, wide viewing angle, high resolution, and excellent image stability. MEP materials can be easily printed on large plastic sheets and laminated to a variety of electronic backplanes to construct displays. The combination of a MEP material with flexible transistor technologies enables displays that offer both the look and form of the printed page. This article reviews the basic architecture and properties of MEP materials and describes the integration of MEP materials with transistor backplanes to produce high-resolution, low-power, paperlike displays. Recent developments in ultrathin flexible displays are also reported.
Plasma Display Materials
Authors: Nonomura Kinzo , Higashino Hidetaka , Murai Ryuichi 
Published: February 2011

AbstractRecent trends in the development of plasma display panels (PDPs) are reviewed in this article with special emphasis on materials. New developments in the panel structure, discharge gases and phosphors used, and drive methods have improved many of the display characteristics over a wide range of operating conditions. As a result, much progress has been seen in large-scale panel development; for example, 50-in. and 61-in. PDPs have been commercialized. Improvements in phosphor longevity, discharge gas efficiency, and characteristics of the protective layers can be attributed in part to materials solutions. The longevity of the blue phosphor has been improved by the development of new materials and a greater understanding of the phosphor deterioration mechanism. The luminous efficiency has been greatly increased by the use of high-density Xe gas. The protective-layer characteristics have been improved as a result of advancements in processes, materials, and analytical methods.
Testing the Fundamental Theories of Surface Dynamics
Authors: Bartelt N. C. 
Published: February 2011

AbstractThe following article is based on the MRS Medal talk by Norm Bartelt (Sandia National Laboratories, California), presented at the 2001 Materials Research Society Fall Meeting on November 29 in Boston. Bartelt received the Medal for his “contributions to the statistical mechanics of materials surfaces.” A long-standing goal of materials science research has been to predict the long-term evolution of the microstructure of materials from a knowledge of atomic processes. This is usually extremely difficult to do in any detail because of the large number of atomic processes to consider, many of which are poorly understood. On solid surfaces, however, progress in the prediction of microstructural evolution can now be made because of advances in real-time microscopy that allow the characterization of the time evolution of microstructure in unprecedented detail. These observations directly reveal the complex relationships between collective thermal fluctuations on atomic scales and deterministic behavior on macroscopic scales. In this presentation, attempts to construct models of these observations are discussed.
The Use of Superelasticity in Modern Medicine
Authors: Duerig T. W. 
Published: February 2011

AbstractThe value of Nitinol (Ni-Ti) in the field of medicine has proven to be far greater than just as the simple “springy metal” it was once considered to be. In particular, its use in vascular implants highlights many valuable yet subtle behaviors, including a “biased stiffness,” enhanced fatigue resistance, low magnetic susceptibility, and good biocompatibility. Nitinol today is nearly as well known to medical-device designers and physicians as are stainless steel and titanium, and it is the enabling ingredient in a growing number of successful and profitable life-saving devices.
Understanding Precursor Phenomena for the R-Phase Transformation in Ti-Ni-Based Alloys
Authors: Shindo Daisuke , Murakami Yasukazu , Ohba Takuya 
Published: February 2011

AbstractPrecursor phenomena are critical issues for martensitic transformations. In this article, we show recent progress in understanding precursor phenomena to the R-phase transformation, which is important for both fundamentals and applications. Structural modulation in the parent phase was intensively studied by means of detailed analyses of the weak diffuse scattering of electrons with the aid of recently developed energy-filtered transmission electron microscopy coupled with x-ray diffraction. A peculiar domain-like structure, which originates from static transverse atomic displacements in the parent phase, was discovered by virtue of these advanced methods. The characteristics of this structure (e.g., size, shape, and temperature-dependence), as well as its role in the subsequent R-phase transformation, are discussed.