Organic-based interfaces can possess a range of surprising electronic properties that are of intense interest from both the basic science and the applied research points of view. In this issue of MRS Bulletin, we provide state-of-the-art overviews of selected topics involving three complementary aspects of the electronic properties of organic-based interfaces: the nascent electronics technologies that would gain from improved understanding and control of such interfaces; the novel properties that organic-based interfaces may possess; and the experimental and theoretical challenges afforded by such studies.

Recent advances in x-ray and neutron sources, optics, and scattering methods are heralding a new age in the study of the structure and properties of complex materials. By providing unprecedented resolution in real space, reciprocal space, and time, new techniques address materials characterization challenges beyond anything possible before, at length scales ranging from the atomic scale to the mesoscale, and at times as short as femtoseconds. The high degree of coherence of third-generation synchrotron sources permits a new level of precision in the quantitative description and analysis of diffraction and scattering and allows beams with sizes probing individual nanostructures to be produced. As a result, in situx-ray and neutron analysis techniques now provide insight into the structure of nanomaterials and yield a more precise set of metrics describing the nanometer-scale structure of materials. Time resolution and in situ studies allow application of these techniques to materials driven far from equilibrium and to the challenging environment associated with materials processing.

To explore higher, farther, and faster, scientists and engineers have developed advanced materials for manned spacecraft and satellites for a range of sophisticated applications in transportation, global positioning, exploration, and communication. Materials used in space are exposed to vacuum, intense ultraviolet radiation from the sun, and ionizing radiation that results in material damage as well as charging (electrostatic discharge effects), micrometeoroids and debris impacts, and thermal cycling (typically from -175 to 160°C). In terms of materials degradation in space, the low Earth orbit (LEO), where LEO is defined as 200—1000 km above the Earth’s surface, is a particularly challenging synergistic environment, since atomic oxygen (AO) is present along with all other environmental elements. Hence, this special issue focuses primarily on the materials issues experienced in LEO by space environmental exposure, such as on the exterior of the International Space Station and the Hubble Space Telescope, and the challenges and opportunities of ground-based laboratory sources to mimic LEO. The combination and comparison of both in-flight and groundbased experiments are needed for the development of predictive understanding of the materials degradation and AO passivation mechanisms in LEO. Such insights are essential for the development of advanced materials and coatings to ensure the longterm durability and performance of vehicles employed in space.

In biology, organic-inorganic hybrid materials are used for several purposes, in particular, for protection and mechanical support. These materials are generally optimized for their function through precise control over the structure, size, shape, and assembly of the component parts and can be superior to many synthetic materials. The shapes and forms of minerals encountered in nature strongly contrast with those that are generally formed in a synthetic environment. According to current understanding, this is achieved through different modes of control: their shape can be controlled by restricting their growth to a confined space or by influencing their preferred direction of growth; in addition, for crystalline materials, polymorph selection and oriented nucleation are achieved through specific interactions between a template or additive and the developing nucleus. Also, controlled arrangement of nanoparticles into superstructures can lead to a complex structure. The understanding and, ultimately, the mimicking of these processes will provide new synthetic routes to specialized organic-inorganic hybrid materials. On the other hand, transformation of existing complex hierarchical natural structures such as wood or diatom frustules into other materials using shape-preserving chemistry is another approach toward minerals with complex biomimetic structure. The theme topic in this issue will focus on recent biomimetic and bioinspired approaches used to achieve control over the shape and organization of mineral and organic-inorganic hybrid materials. The different contributions will also highlight the advantages of these methods for advanced materials synthesis, and possible applications will be discussed.

For more than two decades, scientists and engineers have focused on impending limitations (from high-power densities and heat distribution to device patterning) that constrain the future miniaturization of conventional silicon technology. Thus far, academic and industrial efforts have risen to the challenge and continue to advance planar silicon processing, pushing traditional microtechnology to the nanometer scale. However, insurmountable limitations, both of physical nature and cost, still loom and motivate the research of new nanomaterials and technologies that have the potential to replace and/or enhance conventional silicon systems. As time has progressed, another Group IV element has emerged as a front-runner, looking beyond silicon, in the form of carbon-based nanotechnology. The focus of this issue is to provide a comprehensive look at the state-of-the-art in carbon-based nanomaterials and nanotechnologies and their potential impact on conventional silicon technologies, which are not limited to electronics but also encompass micro- and nanoelectromechanical systems, optoelectronics, and memory. Recent advances in carbon nanotube growth, sorting, and optoelectronics will be discussed, and the relatively new and surging area of graphene research will be introduced. In addition, progress in controlling the growth and properties of ultrananocrystalline and nanocrystalline diamond thin films will be reviewed. These efforts are multidisciplinary, heavily materials focused, and tend to translate information and ideas to other carbon-based studies (e.g., graphene is the building block of carbon nanotubes).

When MRS Bulletin published its expanded special issue in April 2008, “Harnessing Materials for Energy,” it was not a project done lightly. The impetus for this effort was the desire to describe the veritable options that materials provide in energy technologies. These options can then be evaluated in the context of other imperatives such as economic viability and environmental concerns, which all interact to determine societal choices for energy.

A central goal of materials science is to reveal how a material deforms under mechanical stress and how the deformation is related to its microstructure. This goal is best achieved by “seeing” the evolving microstructure when the property is measured quantitatively. Mechanical testing methods have thus evolved over time to test materials at the micro- and nanoscale while observing the changes in the specimen. Recent advances in microtechnology offer a new generation of microscale sensors and actuators that allow in situ studies of both living and nonliving materials in analytical instruments. Such experiments are providing new and fundamental insights on the structure-property relations in materials and revealing remarkable links between the mechanical properties of living cells and their functions. This issue presents five articles that discuss state-of-the-art methodologies for in situ mechanical tests and highlights new findings through the use of these techniques.

Exciting and far-reaching experiments in sustainable energy have been conducted for the last 100 years in many parts of the world. Many of the initiatives work in their respective regions because of the availability of raw products or intense political will, as seen in Germany's solar effort and France's nuclear policy. Others result from the need to be self-reliant, such as the Brazilian effort to produce ethanol with their plentiful sugarcane crop and the Danish efforts to harvest offshore wind. Many of these experiments have been carried out at a large scale with the goal of producing more than 10–30% of the regions' energy needs.

Actinide materials, which are the backbone of nuclear energy, are being examined with growing interest due to the pressing need for carbon-free energy production. Prospects for advanced fuels for next-generation reactors demand a solid understanding of the physical properties of actinide materials, including thermodynamics and quantum mechanics. In this issue of MRS Bulletin, six articles give a broad overview of the current state of actinide science, illustrating current advances and emerging areas of interest in this class of materials, and how this fundamental understanding supports nuclear energy.

The mammalian physiology represents a level of sophistication in materials design, assembly, and function that has yet to be replicated by the modern tools of materials science. Although, the building blocks of our body (pluripotent stem and progenitor cells) are still available within our tissues, the absence of the biological and structural cues that drove the development process early on, in an adult, limits our ability to regenerate after an injury. The goal of regenerative medicine is therefore to recapitulate embryonic events within an artificially defined materials space (i.e., the niche) so that the repair processes can be triggered using our reservoir of stem cells. This engineering of the regenerative niche will require an interdisciplinary exercise involving materials scientists, biologists, and clinicians. The success of this exercise will hinge on our ability to develop materials that incorporate principles of wound healing, lessons from immunology and developmental biology, and knowledge of cellular mechanics and molecular biology such that they can mimic the cellular environment, instruct cells to make fate decisions, and direct the hierarchical organization of tissues. This article presents the current state of this challenge in the implementation of regenerative therapies.

The drive for greater use of renewable materials is one that has recently gained momentum due to the need to rely less heavily on petroleum. These renewable materials are defined as such since they are derived from plant-based sources. Some renewable materials also offer properties that conventional materials cannot provide: hierarchical structure, environmental compatibility, low thermal expansion, and the ability to be modified chemically to suit custom-made applications. Nature's materials, particularly from plant- and animal-based polysaccharides and proteins, have hierarchical structures, and these structures can be utilized for conventional applications via biomimetic approaches. This issue begins with an article covering renewable polymers or plastics that can be used to generate block copolymers (where two polymers with specific functions are combined) as an alternative to conventional materials. Applications of renewable polymers, such as cellulose from plants, bacteria, and animal sources, are also covered. Also presented are the use of bacterial cellulose and other plant-based nanofibers for transparent electronic display screens and, in a wider sense, the use of cellulose nanofibers for composite materials, where renewable resources are required to generate larger amounts of material. Finally, this issue shows the use of biomimetic approaches to take the multifunctional properties of renewable materials and use these concepts, or the materials themselves, in conventional materials applications.

Hybrid macromolecules composed of two or more covalently connected segments have the ability to self-assemble into nanostructured materials. These fascinating materials are used in applications ranging from footwear to bitumen modification to microelectronics. The number of technologies that utilize or could benefit from multiphase polymers is expanding at a rapid rate. This growth is due to the development of simple scalable synthetic technologies, a deeper understanding of their structure-property relationships, and their effectiveness as low-level additives. As industrial uses of self-assembled polymers become more prevalent, there will be a heightened focus on alternative preparative approaches that do not rely on petroleum feedstocks. Therefore the development of biorenewable multiphase polymers is an important research endeavor. In this article, we will explore the synthesis, self-assembly, and properties of renewable block and graft copolymers that contain aliphatic polyesters, as well as bio-sourced segmented polyurethanes. These two classes of multiphase polymers are the most promising and practical candidates for implementation in the next generation of sustainable materials.

When we think of space, we typically think of a vacuum containing very little matter that lies between the Earth and other planetary and stellar bodies. However, the space above Earth's breathable atmosphere and beyond contains many things that make designing durable spacecraft a challenge. Depending on where the spacecraft is flying, it may encounter atomic oxygen, ultraviolet and other forms of radiation, charged particles, micrometeoroids and debris, and temperature extremes. These environments on their own and in combination can cause degradation and failure of polymers, composites, paints and other materials used on the exterior of spacecraft for thermal control, structure, and power generation. This article briefly discusses and gives examples of some of the degradation experienced on spacecraft and flight experiments as a result of the space environment and the use of ground and space data to predict durability.

Microorganisms moderate local chemical conditions and alter forms of metals indirectly or directly to meet their cellular, species, and consortia needs. The diversity of microorganisms and the complexity of biogeochemical systems ensures that bacterially mediated processes yield a wide range of products, which await discovery by material scientists. Few types of materials produced by environmental bacteria have been analyzed by modern chemical and material science methods. Research on actinide biomaterials has focused on the biomineralization of a few chemical forms of uranium, neptunium, and plutonium. The materials produced are molecular complexes, microcrystalline minerals (most commonly oxides and phosphates) within cells and biofilms, and mineral adsorbates. The actinide biomaterials that emerge from this new research area will impact nuclear waste isolation and increase our understanding of environmental and geological metal cycles and may yield new bioremediation methods and industrially useful materials.

This article is devoted to recent progress in the area of in situ electron microscopy (scanning and transmission) and will focus on quantitative aspects of these techniques as applied to the deformation of materials. Selected recent experiments are chosen to illustrate how these techniques have benefited from improvements ranging from sample preparation to digital image acquisition. Known for its ability to capture the underlying phenomena of plastic deformation as they occur, in situ electron microscopy has evolved to a level where fully instrumented micro- and nanomechanical tests can be performed simultaneously.

Surfaces and buried interfaces play critical roles in many environmental, catalytic, and tribological processes and in a wide variety of applications, including microelectronics and optoelectronics. Interfacial structure and composition are closely coupled to their surroundings, and probes that yield information about materials in situ are essential to obtain a thorough understanding of interface functions and properties. The highly brilliant, hard x-rays available from synchrotron light sources can easily penetrate through gas or liquid environments, or even solid thin-film overlayers, and enable real-time monitoring of the evolving chemistry and structure of the interface with atomic-scale resolution. Here we review the in situ study of interfaces by a variety of synchrotron x-ray scattering techniques and provide several examples of their application in electrochemical processes and thin-film island growth. We also discuss recent advances in analytical techniques and x-ray optics that are facilitating the in situ study of surfaces and buried interfaces with direct imaging.

Amorphous silica is (next to CaCO3) the second most abundant biologically produced inorganic material. A certain group of photosynthetic microalgae, called diatoms, forms complex 3D silica architectures (frustules) containing regularly arranged nanoscale features (pores, channels, protuberances). Recently, biomolecules involved in diatom silica formation have been characterized, and first insights into their structure-function correlations have been obtained. This has spurred the development of synthetic (bio)polymers capable of directing the in vitro formation of silica and other inorganic materials from aqueous precursor solutions under mild conditions. Here we present a summary of current insight into the mechanism of silica formation by diatom biomolecules and provide examples of synthetic (bio)polymers for the formation of silica and titania materials with complex structures.

Improved battery technology, innovative recharging strategies, and generous financial incentives are making electric vehicles more attractive to consumers than ever before.