SEM & Imaging

A scanning electron microscope (SEM) can be used across a number of industrial, commercial, and research applications. It’s a type of microscope that produces images of a sample by scanning the surface with a focused beam of electrons. The electrons interact with the atoms in the sample, producing various signals that contain information about the surface topography, morphology and composition of the sample. Various types of signals are produced, including secondary electrons (SE), reflected or back-scattered electrons (BSE), characteristic X-rays and light (cathodoluminescence) (CL), absorbed current (specimen current), and transmitted electrons.

SEMs have become a powerful and versatile tool for material characterisation. This is especially so in recent years due to the continuous shrinking of the dimension of materials used in various applications.

SEM & imaging techniques

There are a number of different SEM & imaging techniques, with three of the major ones discussed below:

Static image analysis

In particle characterisation, a distinction is made between static and dynamic image analysis. Dynamic image analysis is ideal for the routine analysis of bulk solids. With high sample throughput and low susceptibility to errors, this method is a great alternative to conventional sieve analysis.

Static image analysis is generally used for narrow size distributions, with a focus on the precise characterisation of mostly fine particles. This method acquires high-resolution particle images that allow for size and shape measurement with the highest level of accuracy. Static image analysis is based on a microscopic procedure in which a slide is photographed step by step and the particle images evaluated automatically.

Ptychographic quantitative phase imaging

Phase imaging techniques are an invaluable tool in microscopy for quickly examining thin, transparent specimens.

Quantitative phase imaging detects minute changes in phase when light propagates through the cell morphology, and it has become the most common approach for fine cell structure distinction without employing higher radiation powers thereby reducing phototoxicity.

Ptychography employs a technique that uses the intensity of light that is scattered, or diffraction patterns of light created, to produce a pattern on a CCD camera. This scattering pattern of light is passed through the Ptychography algorithm to build a high contrast image. It’s recognised as a unique technique, offering several advantages over traditional QPI. Collecting these scattering patterns and processing them through the algorithm elucidates many advantages over traditional microscopy, namely post acquisition focus, high contrast images and minimal light damage to the sample.

Desktop SEM

Desktop SEM provides direct access to the high-resolution and high-quality imaging and analysis required in a large variety of applications. This user friendly tool bridges the gap between the optical microscope and ultra high-resolution electron microscopes. The Phenom Pro Desktop SEM, for example, exceeds the resolution of optical microscopes and eliminates the expense, delay and difficulty associated with operating a traditional SEM. With an integrated X-ray analysis system, sample structures can be physically examined and their elemental composition determined.

Instruments used in SEM & imaging

There are a number of different instruments used in SEM & imaging, including the following:

• Malvern Morphologi 4
• Malvern Morphologi 4-ID
• Phasefocus Livecyte
• Phenom Pharos Desktop SEM
• Phenom GSR Desktop SEM
• Logos Biosystems Celena X
• Logos Biosystems LUNA FX7

Application areas of these instruments include immunological, neurobiological, cancer and basic cell biology research.

ATA Scientific and SEM & imaging

At ATA Scientific our suppliers include some of the world’s most well-regarded companies such as Malvern Panalytical, Phenom World (now part of Thermo Fisher Scientific), Avestin, Phasefocus, Logos Biosystems, Cellbox Solutions and Micromeritics.

Our people have an extensive range of skills and experience in analytical technologies, especially particle and protein characterisation. As well as supplying modern SEM and imaging instruments, we can support you with ongoing applications assistance and encouraging the adoption of standard operating procedures. Advice regarding instrument operation and optimisation of data quality are freely available by phone and email.

If your research or scientific organisation is looking for the world’s best laboratory equipment and expert support for SEM & imaging, contact us to discuss your requirements.