Nanotechnology and smart-coating technologies have been reported to show great promise for improved performance in critical areas such as corrosion resistance, durability, and conductivity. This article exemplifies nanofilms and nanomaterials used in coatings applications, including carbon nanotubes, silica, metals/metal oxides, ceramics, clays, buckyballs, graphene, polymers, titanium dioxide, and waxes. These can be produced by a variety of methods, including chemical vapor deposition, plasma arcing, electrodeposition, sol-gel synthesis, and ball milling. The application of nanotechnology and the development of smart coatings have been dependent largely on the availability of analytical and imaging techniques such as Raman spectroscopy, scanning and transmission electron microscopy, atomic force microscopy, and scanning tunneling microscopy.

This article provides a brief introduction to lubrication as a method to reduce friction between two surfaces. It discusses the surface characteristics of parts and explores how lubrication helps separate two contacting surfaces and thereby decreases the coefficient of friction. The article details the classifications of lubrication regimes, namely, boundary, mixed, hydrodynamic, and elastohydrodynamic lubrications. It discusses the various types of lubricant materials and additives, including liquid lubricants, solid lubricants, gaseous lubricants, greases, green lubricants, and nanomaterials. The article also reviews the properties of lubricants. It describes the tribological evaluation of lubricants, including stribeck test, four-ball test, block-on-ring test, pin-in-vee test, and reciprocating motion test.

The biocompatibility of a material relates to its immunological response, toxicity profile, and ability to integrate with surrounding tissue without undesirable local or systemic effects on a patient. This article underscores the transformation of the medical device design ecosystem engaged as an integral part of the device ecosystem. It discusses the applications of biomaterials, including orthopedic, cardiovascular, ophthalmic, and dental applications. The article describes four major categories of biomaterials such as metals, polymers, glass and ceramics, and composites. A discussion on natural materials, nanomaterials, and stem cells is also provided. The article concludes with examples of biomaterials applications, such as endovascular devices, knee implants, and neurostimulation.

This article is an overview of the division Surface Analysis of this volume. The division covers various developed surface-analysis techniques, such as scanning probe and atomic force microscopy. The division focuses on the analysis of surface layers that are less than 100 nm. A quick reference summary of surface-analysis methods is presented in this article.

This article discusses electrospinning as a method for obtaining nanofibers, some of the challenges and limitations of the technique, advancements in the field, and how it may be used in key functional applications. The key drawbacks of traditional electrospinning processes include relatively slow speed of nanofiber production, low product yield, and relatively high cost. The article also addresses novel high-throughput techniques and methods designed for the scalable synthesis of nanofibers and nanofibrous mats that are of reasonable cost.

Additive manufacturing (AM) has been adopted as one of the most versatile and rapid design-to-manufacturing approaches for printing a wide range of two- and three-dimensional parts, devices, and complex geometries layer by layer. This article provides insights into the current progress, challenges, and future needs of AM of electronics from the space, defense, biomedical, energy, and industry perspectives.

This article introduces various techniques commonly used in the characterization of semiconductors, namely single-crystal, polycrystalline, amorphous, oxide, organic, and low-dimensional semiconductors and semiconductor devices. The discussion covers material classification, fabrication methods, sample preparation, bulk/elemental characterization methods, microstructural characterization methods, surface characterization methods, and electronic characterization methods.

This article briefly discusses popular techniques for metals characterization. It begins with a description of the most common techniques for determining chemical composition of metals, namely X-ray fluorescence, optical emission spectroscopy, inductively coupled plasma optical emission spectroscopy, high-temperature combustion, and inert gas fusion. This is followed by a section on techniques for determining the atomic structure of crystals, namely X-ray diffraction, neutron diffraction, and electron diffraction. Types of electron microscopies most commonly used for microstructural analysis of metals, such as scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy, are then reviewed. The article contains tables listing analytical methods used for characterization of metals and alloys and surface analysis techniques. It ends by discussing the objective of metallography.

This article presents an overview of the science and engineering of materials along with suitable definitions, descriptions, and examples for better understanding for corrosionists with limited field knowledge. It begins with a detailed description of various categories of engineering materials and moves into the discussion of physical properties of materials, such as the phases, strength, conductivity, and wear. The article describes the methods used in the fabrication of engineering materials and summarizes the materials and their properties in a tabular form. The article concludes with information on material design, materials applications, and materials failure analysis.

This article discusses the application of friction stir processing (FSP) and friction surfacing for tribological components. It describes the three critical aspects involved in the application of FSP for near-surface material modifications intended for tribological applications. These include tools, processing parameters, and machines. The article also discusses the equipment and processing parameters for friction surfacing. It describes various hybrid stir processing techniques that involve preheating of the workpiece material, especially relatively hard and high-strength ones. The article presents a partial list of surface-modification methods based on FSP. The partial list includes surface hardening, surface composites, and additive coating. The article also provides information on generation of residual stresses in metallic materials and alloys form different variants of FSP.

This article introduces various analytical techniques commonly used in the characterization of organic solids and liquids and discusses the challenges in performing the analysis, with examples. Some general advice in approaching a material analysis is also provided.

An ankle-foot orthosis (AFO) is a support designed to regulate the ankle's position and mobility, compensate for weakness, or rectify abnormalities. This article focuses on the biomechanical affects and mechanical properties of custom-made 3D-printed AFOs and compares them to traditionally created AFOs. Investigations in the fields of 3D scanning, 3D printing, and computer-aided design and analysis for the production of custom-made AFOs are also covered.

Aerosol jet printing (AJP) can digitally fabricate intricate patterns on conformal surfaces with applications that include flexible electronics and antennas on complex geometries. Given the potential performance and economic benefits, aerosol jetting was studied and compared with the well-known and competing inkjet printing (IJP). More than 35 of the most relevant, highly cited articles were reviewed, focusing on applications requiring fine features on complex surfaces. The following performance indicators were considered for the comparison of AJP and IJP, because these aspects were the most commonly mentioned within the included articles and were identified as being the most relevant for a comprehensive performance assessment: printing process, line width, overspray, complex surface compatibility, diversity of printable materials, and deposition rate. This article is an account of the results of this comparison study in terms of printing capabilities, ink requirements, and economic aspects.

This article presents a summary of the current and new materials and processing techniques for thermal barrier coatings (TBCs) and environmental barrier coatings (EBCs). Different thermal spraying and postspraying processing techniques are required to produce coatings with optimal performance. For TBCs and EBCs, the elastic modulus, mechanical strength, and toughness values are extremely important in predicting failure behavior under stress and strain conditions, mainly for modeling purposes. Sand and/or volcanic ash particles are molten in the hot zones of turbines and deposited over TBCs and EBCs. They form calcium-magnesium-aluminosilicate (CMAS) glassy deposits.

Materials resulting from thermal spray processes are often different from their wrought, forged, and cast counterparts. Assessing the usefulness of thermal spray coatings requires understanding, developing, and using appropriate testing and characterization methods that are generally borrowed from other materials science disciplines. This article focuses on commonly used testing and characterization methods: metallography, image analysis, hardness, tensile adhesion testing, corrosion testing, x-ray diffraction, non-destructive testing, and powder characterization. It provides information on how the materials themselves respond to the various test methods. The article focuses on the test methods themselves, including those test parameters that can be varied and the influence of each on the results obtained.

The thermomechanical processing (TMP) of conventional and advanced nickel and titanium-base alloys is aimed at altering or enhancing one or more metallurgical features within the material and component. This article presents a number of examples of the TMP of nickel-base superalloys and titanium alloys. The TMP techniques include retained-strain processing, dual-microstructure processing, and dual-alloy processing. The article also describes the TMP of alpha-beta titanium alloys, including fine-grain processing, hybrid-structure processing, dual-microstructure processing, and dual-alloy processing. It concludes with a discussion on computer simulation of advanced TMP processes.

Piezoelectric jetting is a common form of additive manufacturing technology. With the development of material science and manufacturing devices, piezoelectric jetting of biomaterials has been applied to various fields including biosensors, tissue engineering, deoxyribonucleic acid (DNA) synthesis, and biorobots. This article discusses the processes involved in piezoelectric jetting of biosensors and biorobots and the applications of piezoelectric jetting for tissue engineering and producing DNA. In addition, it reviews the challenges and perspectives of piezoelectric jetting.

Additive manufacturing (AM) security is considered an integral part of several broader security fields, including supply chain security and critical infrastructure security. This article presents a general guide to the types of data and locations of data as they may exist in a typical AM-using organization. It discusses the following threat categories: technical data theft, sabotage, illegal part manufacturing, and data infiltration and exfiltration. The article also presents a detailed discussion on countermeasures against threat categories.