Bright-field illumination is widely used as standard technique for examination of transparent specimens characterized by an appropriate optical density so that the transmitted light is partially absorbed when passing the specimens (for example, stained histological sections and blood smears). On the other hand, thin and colorless low-density specimens, such as unstained living cells that do not reduce the amplitude of the transmitted light, cannot be well perceived in bright field because of their ultra-low natural contrast. These so-called phase specimens can be examined when an apparatus for phase contrast is used. Phase contrast can be carried out with special objectives fitted with a phase ring situated within or near their back focal plane. Moreover, the condenser must be fitted with annular light masks (light annuli) that are projected onto the plane of the objective's phase ring so that both components, light annuli and phase rings, are optically congruent and conjugate.

Ground state depletion (GSD) microscopy is a form of super-resolution light microscopy suggested almost a decade ago but demonstrated practically in 2007. In principle, this is a parallel recording wide-field approach that temporarily switches the majority of fluorophores off to allow the precise localization of single fluorophores. Almost all fluorophores in the sample are turned dark by high-intensity laser excitation, leaving only single, well-separated fluorophores emitting fluorescence. The precise localization of the fluorescent dyes is then determined to produce images with a resolution in the 20- to 50-nanometer range. One of the key advantages of this method over other localization techniques is that it can be used with standard fluorescence labels routinely applied in biomedical research.

Computed tomography (CT) has been commonly used in medicine for assessing the anatomy of humans in conventional computer axial tomography (CAT) scans. It is also a very common tool for assessing the architecture of trabecular bones for diagnosis of conditions such as osteoporosis. More recently, high-resolution CT (micro-CT) has found increasing use in materials science for the evaluation of the internal structure of a variety of advanced materials for industrial applications. Knowledge of the micro-architecture of these materials is extremely important to better understand their performance. Micro-CT is a non-destructive 3D characterization tool that uses X rays to determine the internal structure of objects through imaging of different densities within the scanned object. High-resolution laboratory-based micro-CT or nano-CT provides image resolution on the order of 300 nm. Such high resolution allows one to visualize the internal 3D structure of fine-scale features. The data from micro-CT results in a virtual rendering of the object under investigation, which allows one to travel through the volume in any direction and angle, revealing complex hidden structures within the object. Thus, micro-CT can be an important complementary technique for a microscopy laboratory.

Microscope users can become fatigued by awkward sitting positions and complicated controls. This affects many users in microbiology, cytology, hematology, and pathology labs. In recent years researchers have conducted studies to examine microscope ergonomic issues for users with various body heights. This research is critical because data from occupational and medical literature clearly indicate that occupational-based injuries at the workplace are common where microscopes are used extensively. Muscular-skeletal conditions, including shoulder, neck, and back aches, are the most prevalent injuries, with more than 77% of users experiencing these issues.

What have we achieved in this period?

We demonstrate in this article an exciting new method for obtaining electron Kikuchi diffraction patterns in transmission from thin specimens in a scanning electron microscope (SEM) fitted with a conventional electron backscattered diffraction (EBSD) detector. We have labeled the method transmission EBSD (t-EBSD) because it uses off-the-shelf commercial EBSD equipment to capture the diffraction patterns and also to differentiate it from transmission Kikuchi diffraction available in the transmission electron microscope (TEM). Lateral spatial resolution of less than 10 nm has been demonstrated for particles and better than 5 nm for orientation mapping of thin films. The only new requirement is a specimen holder that allows the transmitted electrons diffracted from an electron transparent sample to intersect the EBSD detector. We briefly outline our development of the technique, followed by descriptions of sample preparation techniques and operating conditions. We then present examples of t-EBSD patterns from a variety of specimens, including particles of diameter <10 nm, wires of diameter <80 nm, and films with thicknesses from ~5 nm to 300 nm. Finally, we discuss the phenomenon in the context of Monte Carlo electron scattering simulations.

Atomic force microscopy (AFM) has been widely used in both industry and academia for imaging the surface topography of a material with nanoscale resolution. However, often little other information is obtained. Contact resonance AFM (CR-AFM) is a technique that can provide information about the viscoelastic properties of a material in contact with an AFM probe by measuring the contact stiffness between the probe and sample. In CR-AFM, an AFM cantilever is oscillated, and the amplitude and frequency of the resonance modes of the cantilever are monitored. When a probe or sample is oscillated, the tip sample interaction can be approximated as an ideal spring-dashpot system using the Voigt-Kelvin model shown in Figure 1. Contact resonance frequencies of the AFM cantilever will shift depending on the contact stiffness, k, between the tip and sample. The damping effect on the system comes from dissipative tip sample forces such as viscosity and adhesion. Damping, η, is observed in a CR-AFM system by monitoring the amplitude and Q factor of the resonant modes of the cantilever. This contact stiffness and damping information can then be used to obtain information about the viscoelastic properties of the material when fit to an applicable model.

As electron microscopists, many of us become engrossed in observing the shape, size, and atomic structure of nanoparticles every day. With our focus on the atoms in a single quantum dot, it is easy to lose sight of the broader physical perspective. This short essay highlights some wider connections as a way of linking electron microscopy to the quest for knowledge on other length scales. The scientific enterprise relies on images that expand the range of human vision, from the galactic to the atomic, from the origins of the universe to the discovery of new materials. From this viewpoint, it is interesting to look at some connections across nearly 30 orders of magnitude.

Cosmic ray particles were discovered by Victor Hess on August 7, 1912, leading to his co-winning the Nobel Prize in Physics in 1936. Initially thought to be rays (photons), in the 1920s they were recognized as being charged particles. I describe in this article how I acquire and process images of cosmic ray particles (CRPs) on a microscope with a digital camera in the imaging core facility I manage.

Since our beginning close to 30 years ago, Electron Microscopy Sciences has been specializing in the manufacturing, preparation, and distribution of only the highest quality chemicals, supplies, and equipment, for microscopy and histology as well as all of its related fields.

Scanning electron microscopy (SEM) and ion beam milling techniques are mature nanoscale measurement technologies, whereas atomic force microscopy (AFM) is a developing technology generating intense interest in the scientific community for basic research and development. These techniques have generally existed in separate worlds. This article discusses a capability that marries these technologies through an instrument recently introduced by Nanonics, the 3TB4000.

The microspectrophotometer can be described as a type of hyphenated instrument: it is a hybrid that combines the magnifying power of a light microscope with a UV-visible-NIR (ultraviolet–visible–near infrared) range spectrophotometer. These instruments are used to measure the molecular spectra from microscopic samples, from the deep ultraviolet to the near infrared region. Microspectrophotometers can be configured in many different ways and used to measure absorbance, reflectance, and even emission spectra, such as fluorescence, of sub-micron-sized sample areas. With the addition of specialized algorithms, the microspectrophotometer can also be used to measure the thickness of thin films or to act as a colorimeter for microscopic samples.

Traditional electron detectors for scanning electron microscopes (SEMs) are the Everhart-Thornley detector located on one side of the specimen and the overhead backscattered electron detector (BSED), usually mounted under the final lens. In 2011 PulseTor introduced an efficient BSED based on scintillator/silicon photomultipler technology that is small enough to be mounted on the tip of an X-ray detector. The scintillator converts the electron signal to light, which is in turn converted to an electrical current in the silicon photomultiplier (SiPM). Silicon photomultipliers were initially developed in Russia in the 1990s. The review article by Dolgoshein et al. cites much of the historical development. Following the recent work of Piemonte and others, the SiPM consists of an array of many identical and independent detecting elements (microcells) connected in parallel on a common Si substrate. Each microcell is an avalanche photodiode only tens of micrometers in size.

X-ray microfocus computer tomography (μ-CT) is a non-destructive experimental technique that reveals the 3D internal microstructure of the sample under study. The experimental set-up consists of an X-ray source, an X-ray detector, and set in between is a sample that is placed on a rotation stage. With this set-up multiple X-ray projection images can be obtained from the sample at different angles. In between the acquisition of two successive images, the sample is rotated over a small angle, typically between 0.2° and 1°. This set of projection images is then used as input for the reconstruction algorithm, which calculates a reconstruction of the internal microstructure of the sample with (sub-) micrometer sensitivity.

The global consumer market wants smaller, faster, more reliable, lower-cost products. The semiconductor industry has responded by the doubling of chip transistor density every two years, closely following Moore's Law. To meet their goals, the industry has made huge investments in R&D and manufacturing to miniaturize components, increase the size of substrates (wafers), improve the productivity of factories, and invent new packaging technology.

Hitachi High Technologies America, Inc. (HTA) provides technologically advanced solutions to meet the diverse and complex challenges of materials science, biological research, and industrial manufacturing. HTA supports our satisfied customers with a wide range of reliability-proven instrumentation, including scanning electron microscopy (SEM), analytical and biological transmission electron microscopy (TEM), dedicated STEM, focused ion beam (FIB), tabletop SEM microscopes, and microanalysis sample preparation systems.

Recently there has been a lot of discussion on the Microscopy Listserver about the fact that it frequently seems to take forever for a vacuum system to pump down to an operating level. It turns out that there are several interesting and fundamental reasons for this. Because of the widespread interest in this topic, it would seem worthwhile to review these reasons briefly. I think that anyone who works with an instrument that has a vacuum system could find this article useful. I am afraid, however, that the fact that it contains a number of mathematical equations will scare some people away. This should not be so, because no difficult mathematical manipulations are involved, and all the equations form the basis for interesting and important relationships, which I hope are described in straightforward, understandable terms.

Up to now, researchers performing analytical investigations in the transmission electron microscope typically had to choose between analytical spectroscopy techniques. They might choose energy dispersive X-ray spectroscopy (EDS) analysis when working with thick samples containing high-Z elements or choose electron energy-loss spectroscopy (EELS) when studying low-Z materials in thin samples. With the advent of STEM instruments possessing both high-mechanical stability and high-brightness probes, coupled with the latest generation of fast, efficient X-ray and EELS detectors, choosing between complementary techniques is a significant restriction. The acquisition systems available up to now have forced a choice because EELS, EDS, and fast scanning have not been designed to work together, resulting in inefficient data collection.

Recently, a highly sensitive imaging mode for, complex, calibrated electrical and spatial measurements was made available to atomic force microscope (AFM) users. Scanning microwave microscopy (SMM), an award-winning AFM mode of operation developed by Agilent Technologies, combines the comprehensive electrical measurement capabilities of a microwave vector network analyzer (VNA) with the nanoscale spatial resolution of an AFM.

Energy-dispersive X-ray spectrometry (EDS) is an analytical technique used to determine elemental composition. It is a powerful, easy-to-use, non-destructive technique that can be employed for a wide variety of materials. In this technique the electron beam of the scanning electron microscope (SEM) impinges on the sample and excites atomic electrons causing the production of characteristic X rays. These characteristic X rays have energies specific to elements in the sample. The EDS detector collects these X rays as a signal and produces a spectrum. Samples also can be excited by X rays. Collimated and focused X rays from an X-ray source produce characteristic X rays that can be detected by the same EDS detector. When X rays are used as the source of excitation, the method is then called X-ray fluorescence (XRF) or micro-XRF.