This article presents an overview of various material models used to represent the mechanical behavior of arteries and the inverse problems posed by the identification of their constitutive parameters. After briefly defining inverse problems and describing the general features of arteries, this article addresses three main queries involving inverse problems and arterial wall characterization: (1) macroscopic identification of the parameters of sophisticated constitutive models from traditional uniaxial and biaxial experiments; (2) mesoscopic identification of regional variations in the material parameters of arteries, tracking the effects of functional adaptation or lesions; and (3) how constitutive models and inverse problems allow information to be obtained on the arterial microstructure and how the structural constituents interact in the mechanical response. Finally, the article shows that while significant effort has been made to relate the complex mechanical behavior of arteries to their microstructure, a new class of inverse problems has recently appeared related to the identification of mechanobiological parameters, which are involved in the numerical models of growth and remodeling.

Multiferroic magnetoelectric nanostructures with coupled magnetization and electric polarization across their interfaces have stimulated intense research activities over the past decade. Such interface-based magnetoelectric coupling can be exploited to significantly improve the performance of many devices such as memories, tunable radio-frequency/microwave devices, and magnetic sensors. In this article, we introduce a number of current or developing technologies and discuss their limitations. We describe how the use of magnetoelectric nanostructures can overcome these limitations to optimize device performance. We also present challenges that need to be addressed in pursuing practical applications of magnetoelectric devices.

Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) exhibit unique electrical, optical, thermal, and mechanical properties, which enable them to be used as building blocks in compact and lightweight integrated electronic systems. The controllable and reliable synthesis of atomically thin TMDCs is essential for their practical application. Recent progress in large-area synthesis of monolayer TMDCs paves the way for practical production of various 2D TMDC layers. The intrinsic optical and electrical properties of monolayer TMDCs can be defined by stoichiometry during synthesis. By manipulating the lattice structure or layer stacking manner, it is possible to create atomically thin van der Waals materials with unique and unexplored physical properties. In this article, we review recent developments in the synthesis of TMDC monolayers, alloys, and heterostructures, which shine light on the design of novel TMDCs with desired functional properties.

This article addresses recent advances in the application of microscopy techniques to characterize crystallization processes as they relate to biomineralization and bioinspired materials synthesis. In particular, we focus on studies aimed at revealing the role organic macromolecules and functionalized surfaces play in modulating the mechanisms of nucleation and growth. In nucleation studies, we explore the use of methods such as in situ transmission electron microscopy, atomic force microscopy, and cryogenic electron microscopy to delineate formation pathways, phase stabilization, and the competing effects of free energy and kinetic barriers. In growth studies, we emphasize understanding the interactions of macromolecular constituents with growing crystals and characterization of the internal structures of the resulting composite crystals using techniques such as electron tomography, atom probe tomography, and vibrational spectromicroscopy. Examples are drawn from both biological and bioinspired synthetic systems.

The ability to understand and control matter at the nanoscale has enabled the development of revolutionary new materials and devices. While nanotechnology is rapidly becoming pervasive in applications such as consumer electronics, health care, and cosmetics, there are only a limited number of examples in which nanotechnology has found its way into aerospace applications. This article discusses the potential of nanotechnology to impact future aerospace missions and vehicles, as well as the technical barriers to its wider use in aerospace.

Crystalline silicon dominates the solar panel industry today but remains relatively expensive to manufacture. If devices could be fabricated from inexpensive materials by a simple solution process without the need for high-temperature annealing, their cost could be considerably reduced. Recently, inorganic–organic (I/O) hybrid systems based on inorganic nanoparticles (including quantum dots) and perovskite materials as light harvesters with organic hole-conducting materials have shown great potential for efficient solar cells due to the combination of superior optical properties and solution-based processes. In this review, we describe the relevant morphological factors and the performance of perovskite solar cells with tuned heterojunctions. In particular, we describe the mediator retarding the rapid crystallization of perovskite layers for a bilayer configuration. Appropriate processes and chemical engineering induced the formation of well-crystallized perovskite materials with extremely uniform and dense perovskite layers and remarkably improved the performance of the cells with a National Renewable Energy Laboratory (NREL)-certified record efficiency of 20.1%.

This article reviews the development of SiC and GaN devices for power-switching applications in the context of four specifically identified application requirements: (1) high-blocking voltage, (2) high-power efficiency, (3) high-switching speed, and (4) normally OFF operation. Specific device and material characteristics, such as ON resistance, parasitic capacitances, and energy-gap values, are compared and discussed in relation to the identified application requirements. Following a review of the fundamental limitations of silicon as a material, this article describes the material advantages that motivated the development of commercially available Schottky diodes and transistors using SiC. The last section analyzes the potential of GaN to enable further technical progress beyond the theoretical limit of Si and to significantly reduce the cost of power-electronic switches.

Efficient, reproducible, and precise methodologies for fabricating tissue engineering (TE) scaffolds using three-dimensional (3D) printing techniques are evaluated. Fusion deposition modeling, laser sintering, and photo printing each have limitations, including the materials that can be used with each printing system. However, new and promising resorbable materials are surfacing as alternatives to previously studied resorbable TE materials for 3D printing. One such resorbable polymer is poly(propylene fumarate) (PPF), which can be printed using photocross-linking 3D printing. The ability to print new materials opens up TE to a wide range of possibilities not previously available. The ability to control precise geometries, porosity, degradation, and functionalities present on 3D printable polymers such as PPF shows a new layer of complexity available for the design and fabrication of TE scaffolds.

The need to understand fast, complex physical phenomena through direct in situ observation has spurred the development of high-time-resolution transmission electron microscopy (TEM). Two complementary approaches have emerged: the single-shot and stroboscopic techniques. Single-shot TEM has advanced through the development of dynamic transmission electron microscopy (DTEM) and, more recently, by the advent of movie-mode DTEM, which enables high-frame-rate in situ TEM experimentation by capturing nanosecond-scale sequences of images or diffraction patterns. Previous DTEM studies produced only single snapshots of fast material processes. Movie-mode DTEM provides the ability to track the creation, motion, and interaction of individual defects, phase fronts, and chemical reaction fronts, providing invaluable information on the chemical, microstructural, and atomic-level features that govern rapid material processes. This article discusses movie-mode DTEM technology, its application in the study of reaction dynamics in Ti–B-based reactive nanolaminates, and future instrumentation.

Superconductivity and magnetism at intermediate (“mesoscopic”) length scales between atomic and bulk have a long history of interesting science. New science emerges due to the presence of multiple length scales, especially when these become comparable to relevant geometric sizes. New phenomena may appear due to topological interactions, geometric confinement, proximity between dissimilar materials, dimensional crossover, and collective effects induced by periodicity. In this review, we select a few, recent highlights that illustrate the type of novel science that can be accomplished in superconducting and magnetic structures. These materials can serve as model systems and provide new ideas, which can be extended to other systems such as ferroelectrics and multiferroics. We also highlight general open questions and new directions in which the field may move.

The field of electronics packaging is undergoing a significant transition to accommodate the slowing down of lithographically driven semiconductor scaling. Three-dimensional (3D) integration is an important component of this transition and promises to revolutionize the way chips are assembled and interconnected in a subsystem. In this article, we develop the key attributes of 3D integration, the enablers and the challenges that need to be overcome before widespread acceptance by industry. While we are already seeing the proliferation of applications in the memory subsystem, the best is yet to come with the heterogeneous integration of a diverse set of technologies, the mixing of lithographic nodes and an economic argument for its implementation based on overall system function, and cost rather than a narrow component-based analysis. Finally, an extension to monolithic 3D integration promises even further benefits.

The methodologies, results, and status of investigations for the development of solvothermal, vapor-phase transport, and solution techniques for bulk crystal growth of large diameter GaN and AlN crystals are presented. This work is being driven by (1) the anticipated need for the initial homoepitaxy of ever-thicker GaN films having very low densities of both threading dislocations and unintentionally introduced, electronically important impurities for devices operating at high and very high load levels; (2) the desire to move from lateral to vertical device structures; and (3) recent results of near theoretical breakdown behavior and near system-level performance in vertical GaN diodes grown on GaN substrates. The choice of the substrate dictates the technique and process routes for the growth of Group III-nitride-based thin films and material device structures. Organometallic vapor-phase epitaxy is the commercial process route of choice for the growth of Group III-nitride films. A review of the precursor gases used in this technique, their stability in the growth reactor and reactivity with nitrogen-containing gases, and the choice of diluent for the growth of films of different nitrides is also presented.

Complex oxides provide an ideal playground for exploring the interplay among the fundamental degrees of freedom: structural (lattice), electronic (orbital and charge), and magnetic (spin). In thin films and heterostructures, new states of matter can emerge as a consequence of such interactions. Over the past decade, the ability to synthesize self-assembled nanocomposite thin films of metal oxides has provided another pathway for creating new interfaces and, thus, new physical phenomena. In this article, we describe examples of such materials systems explored to date and highlight the fascinating multifunctional properties achieved. These include enhanced flux pinning in superconductors, strain-enhanced ferroelectricity, strain- and charge-coupled magnetoelectrics, tunable magnetotransport, novel electrical/ionic transport, memristors, and tunable dielectrics.

Self-assembled epitaxial oxide composite films represent a new material form in which very high-quality mesoscopic structures can be created. The main focus has been on coupled electronic devices, but so far, only a very narrow range of compositions and structure types have been explored. Insufficient attention has been paid to the very wide window of possible materials combinations or to the novel materials properties that could be induced. Both of these aspects need to be addressed before we attain mesoscale devices with new properties. In this article, we review the unique materials properties of these epitaxially directed mesoscale composite structures, discussing their very high crystallinity, structural uniformity, and orientation. We also review how the structures can be size-tuned, from ∼2 nm up to ∼50 nm, and how they can be spatially ordered. We discuss how unusual strain states can be induced in the structures, and how epitaxial stabilization of the mesoscale surfaces within the films eliminates problems of surface degradation inherent to “free” nano/mesostructures. Several exemplar systems are given to show that composite films represent an unrivaled new approach to engineering new properties into mesoscale systems.

Perovskite solar cells based on organolead halide perovskite light absorbers have been considered a promising photovoltaic technology due to their superb power-conversion efficiency along with cheap material cost. Since the first work on long-term durable solid-state perovskite solar cells, a tremendous volume of research on perovskite solar cells has been carried out. A high photovoltaic performance is mainly attributed to the high-quality CH3NH3PbI3 (MAPbI3) material that is strongly dependent on the fabrication method used. MAPbI3 can be prepared by either a single-step procedure or a sequential two-step deposition technique. The two-step method was found, in general, to show better coverage, morphology, and infiltration into a mesoporous oxide layer, which led to high-quality perovskites with desirable optoelectronic properties and thereby high-efficiency perovskite solar cells.