Efficient and reliable particle separators and concentrators are needed to support a wide range of analytical functions including pathogen detection, sample preparation, high-throughput particle sorting, and biomedical diagnostics. The advent of lab-on-a-chip devices based on the phenomenon of dielectrophoresis offers advantages that can meet several of the challenges associated with cell sorting and detection. The majority of the devices presented in the scientific literature have used glass-based devices for these applications, but there has been recent activity that indicates that polymer-based devices can operate as effectively as their glass progenitors. Processing and operational advantages motivate the transition from glass and silicon to polymer microdevices: mechanical robustness, economy of scale, ease of thermoforming and mass manufacturing, and the availability of numerous innate chemical polymer compositions for tailoring performance. We present here a summary of the developments toward, and results obtained from, these polymeric dielectrophoretic devices in the selective trapping, concentration, and gated release of a range of biological organisms and particles.

Computational modeling is a ubiquitous technique in materials science, but until recently this approach has not been widely applied to the drug development process. The formation of particles, their kinematics, and their response to processing stresses are increasingly being studied using computational techniques (computational fluid dynamics and discrete element analysis). These computational techniques can be predictive tools to guide scientists who are designing pharmaceutical dosage forms with specific macroscopic properties. This article gives an overview of the types of computational methods that are used in pharmaceutical materials science and provides examples of their application to some problems from the literature and the authors' own work.

Holographic storage is considered a promising successor to currently available optical storage technologies. Enabling significant gains in both data transfer rates and storage densities, holographic storage and its capabilities have gained a great deal of recent attention.One of the primary challenges in the advancement of holographic storage has been the development of suitable recording materials.In this article, we provide a brief introduction to holographic storage and its potential advantages over current technologies, outline the requirements for recording materials, and survey candidate materials.We end by highlighting recent progress in photopolymer materials that has produced materials that satisfy the requirements for holographic storage and have enabled significant demonstrations of the viability of this technology.

Reasearch and technology developments in the field of spintronics have grown tremendously in the past 10-15 years and already have had a major impact on the data storage industry.The future looks even brighter, as many new spintronic discoveries have been recently made that promise an even bigger impact in the future.This article summarizes the past accomplishments, describes some of the major discoveries that will have a lasting impact on the field, and discusses some of the technologies that may revolutionize data storage in the next decade.

High-throughput experimentation is effective in systematically producing large and diverse data sets. The marriage of combinatorial materials science and informatics is a natural one, and results are beginning to emerge from the integration of elements of materials informatics with data from combinatorial libraries. We discuss data management issues in high-throughput experimentation and highlight recent examples where data-mining tools are being implemented for extracting knowledge and predicting new compounds, with an emphasis on electronic materials.

The following article is an edited transcript based on the Von Hippel Award presentation by Robert Langer of the Massachusetts Institute of Technology on November 30, 2005, at the Materials Research Society Fall Meeting in Boston. Langer was honored with MRS's highest award for his “pioneering accomplishments in the science and application of biomaterials in drug delivery and tissue engineering, particularly in inventing the use of materials for protein and DNA delivery, and for his achievements in interdisciplinary research which have generated new medical products, created new fields of biomaterials science, and inspired research programs throughout the world.”

Solid-supported lipid bilayers hold strong promise as bioanalytical sensor platforms because they readily mimic the same multivalent ligand-receptor interactions that occur in real cells. Such devices might be used to monitor air and water quality under real-world conditions. At present, however, supported membranes are considered too fragile to survive the harsh environments typically required for non-laboratory use. Specifically, they lack the resiliency to withstand air exposure and the thermal and mechanical stresses associated with device transport, storage, and continuous use over long periods of time. Several successful strategies are now emerging to make supported membranes tougher. These strategies incorporate mimics of the cytoskeleton and glycocalyx of real cell membranes. The promise of these more robust lipid bilayer architectures indicates that future materials should be designed to more fully resemble the actual structure of cell membranes.

Historically, thermoelectric technology has only occupied niche areas, such as the radioisotope thermoelectric generators for NASA's spacecrafts, where the low cooling coefficient of performance (COP) and energy-conversion efficiency are outweighed by the application requirements.Recent materials advances and an increasing awareness of energy and environmental conservation issues have rekindled prospects for automotive and other applications of thermoelectric materials.This article reviews thermoelectric energy-conversion technology for radioisotope space power systems and several proposed applications of thermoelectric waste-heat recovery devices in the automotive industry.

In this article, we present summaries of the evolution of surface morphology resulting from the irradiation of single-crystal silicon with femtosecond laser pulses. In the first section, we discuss the development of micrometer-sized cones on a silicon surface irradiated with hundreds of femtosecond laser pulses in the presence of sulfur hexafluoride and other gases. We propose a general formation mechanism for the surface spikes. In the second section, we discuss the formation of blisters or bubbles at the interface between a thermal silicon oxide and a silicon surface after irradiation with one or more femtosecond laser pulses. We discuss the physical mechanism for blister formation and its potential use as channels in microfluidic devices.

The development of a hydrogen-based economy would generate a substantial necessity for efficient means of collecting hydrogen with a relatively high purity. Membrane separations play a major role in the separation of hydrogen gas from various gas mixtures, and this article discusses the use of polymeric materials to produce these membranes. After a review of the historical use of polymeric membranes and some background information regarding mechanisms of gas transport in membranes, this article will review the work that has been done in the two major classes of hydrogen separation membranes: hydrogen-selective membranes and hydrogen-rejective membranes. In hydrogen-selective membranes, the very small size of the hydrogen molecule is exploited to allow rapid diffusion of hydrogen through the membrane while excluding other gases. Hydrogen-rejective membranes use the significantly higher sorption of other gases to overcome the advantages of the small size of the hydrogen molecule. The discussion of these two types of membranes will be followed by a presentation of the current state of the art with regard to polymeric membranes for hydrogen separation and a discussion of the predictions for future applications and advancements in this area.

The use of ultrafast laser pulses is having an impact on materials processing in profound ways. “Machining” with femtosecond pulses affords considerable advantages over nanosecond pulses, such as subdiffraction-limited material ablation, where ablated spot dimensions are below that achievable when longer pulses are focused to the minimum spot size dictated by optical physics. These properties have been exploited to address what had become a critical problem in the semiconductor industry, the repair of patterned photomasks. We will describe how the fundamentals of femtosecond laser ablation have been implemented in a machine designed to repair photomasks. We will also describe experiments designed to deposit Cr metal onto fused-silica substrates using 100-fs, 400-nm light pulses at atmospheric pressure. Multiphoton dissociation of Cr(CO)6 adsorbed on fused-silica substrates initiates Cr deposition. The mechanisms for deposition on both transparent (fused silica) and absorbing (Cr metal) substrates are discussed. Finally, we describe experiments that were carried out to extend the photomask repair process to shorter wavelengths (below 200 nm) using light generated by frequency-mixing of ultrashort, 30-fs pulses in an Ar-filled capillary.

By the end of 2006, the areal density of magnetic recording on tape will approach that seen in hard disk drives of the early to mid-1990s.These operating conditions are reviewed in relation to the operating conditions deemed necessary for the future of magnetic data storage on tape.What results is a clear set of tasks, encompassing both materials and systems architecture issues, to achieve very high-density data storage on magnetic tape, leading to 10 Tbyte tape cartridge capacities and higher.The key to achieving on tape the areal densities of tens to hundreds of Gbit in.2, common in hard disk drives (HDDs), lies primarily in the properties of the medium itself.As for volumetric density of the storage entity, HDDs and tape cartridges are roughly equivalent.The mechanical dimensional uncertainties that accompany the use of flexible, as opposed to rigid, media means that both the mechanical and magnetic properties of materials play a key role in the future of tape.The need for new architectures to overcome the track placement problem that results from increasing track density on flexible media are reviewed, as well as the “particles in a binder” concept that has served so well as the physical basis of tape media over the past 50 years.

The most widely used method of hydrogen production, steam methane reforming, yields a product stream consisting mainly of hydrogen (H2) and carbon dioxide (CO2). Purification of this product is currently accomplished using amine-based acid gas scrubbers or pressure swing adsorption technology. Membranes are well suited to bulk CO2 removal and offer a viable alternative to these established technologies. This review considers one type of such membranes, polymeric facilitated transport membranes. These membranes selectively permeate CO2 by means of a reversible reaction between the gas and the membrane material. In addition, the membrane provides a barrier to H2 permeation. The result is removal of the CO2 contaminant and recovery of the H2 product at high pressure, eliminating the need for recompression prior to use or storage. A wide range of polymeric materials have been investigated, including ion-exchange resins, hydrophilic polymers blended with CO2-reactive salts, polyelectrolytes, fixed-site carrier polymers, and biomimetic materials. This review provides a description of the reaction chemistry of facilitated transport, a summary of membrane permselective properties, and suggestions for future research efforts.

Recordable CDs and DVDs have become household items, and business depends on optical recording technologies for data interchange and archiving. This broad use of optical recording media has been enabled by the development of compatibility standards. Compliance with these standards enables data interchange between products from different manufacturers and between products of different vintages.

This article will discuss what optical recording standards are and describe the standard development organizations that exist to create them. Further, it will provide an overview of the most common standards development process for removable optical recording media. The article will conclude with a discussion of how optical recording media standards enable asset protection and how new optical recording media standards meet the market demand for higher capacities.

Molecules in the cell membrane are key targets for therapeutic intervention. Technologies that enable the preservation of membrane-bound targets in their biomimetic and pharmacologically active states for screening of potential drug compounds are of great interest to bio-pharmaceutical companies. This review discusses emerging biomembrane technologies with a focus on biomembrane microarrays that enable the parallel analysis of multiple membrane-bound targets.