An electron microscope is a microscope that uses a beam of accelerated electrons as a source of light.
At Times the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a much higher resolving power than light microscopes and can thus easily reveal the structure of smaller objects.
Electron microscopes are used to investigate the structure of a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals, and crystals. Industrially, electron microscopes are often used for quality control and failure analysis.
To learn more about why electron microscopes are an excellent piece of equipment and the varying cost of buying one, read on as we have compiled a full breakdown in this article!
What Is An Electron Microscope?
When the electron beam interacts with the specimen, it loses energy by a variety of mechanisms.
The lost energy is converted into alternative forms such as heat, emission of low energy secondary electrons and high-energy backscattered electrons, light emission (cathodoluminescence) or X-ray emissions, all of which provide signals carrying information about the properties of the specimen surface, such as its topography and composition.
The image displayed by an SEM maps the varying intensity of any of these signals into the image in a position corresponding to the position of the beam on the specimen when the signal was generated.
Electron microscopes are expensive to build and maintain, but the capital and running costs of confocal light microscope systems now overlap those of basic electron microscopes.
The samples largely have to be viewed in a vacuum, as the molecules that make up air would scatter the electrons.
Scanning electron microscopes operating in conventional high-vacuum mode usually image conductive specimens; therefore non-conductive materials require conductive coating (gold/palladium alloy, carbon, osmium, etc.).
The low-voltage mode of microscopes makes the observation of non-conductive specimens without coating possible.
Non-conductive materials can also be imaged by a variable pressure (or environmental) scanning electron microscope.
Small, stable specimens such as carbon nanotubes, diatom frustules and small mineral crystals (asbestos fibers, for example) require no special treatment before being examined in the electron microscope.
Samples of hydrated materials, including almost all biological specimens have to be prepared in various ways to stabilize them, reduce their thickness ultrathin sectioning) and increase their electron optical contrast.
Applications Of An Electron Microscope
- Electron microscopes are used to investigate the ultrastructure of a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals, and crystals.
- Industrially, electron microscopes are often used for quality control and failure analysis.
- Modern electron microscopes produce electron micrographs using specialized digital cameras and frame grabbers to capture the images.
- The science of microbiology owes its development to the electron microscope. The study of microorganisms like bacteria, virus, and other pathogens have made the treatment of diseases very effective.
The Cost Of An Electron Microscope
The price of a new electron microscope can really vary between $80,000 to $10,000,000 depending on certain settings and the overall quality, but the average cost of an electron microscope is $294,000.
The price of electron microscopes can also vary by type of electron microscope.
There can be a high degree of variation in the cost of an electron microscope between manufacturers and models.
Pricing for electron microscopes is typically only available upon request for quotation after requirement analysis and specifications are taken from the potential buyer.
However, I have gathered some prices from used electron microscopes and included the estimated cost if the microscope were new to give you a sense of the different costs by electron microscope type and model.
Factors That Go Into The Cost Of A Microscope
The main factors that tend to affect the cost of a microscope will be the configurations, customizations, sample accommodation and achieved resolution.
The better these are in the microscope, the higher the price point is likely to be. There are some other costs that should definitely not be overlooked and these include; training, setup and deployment.
You should also be factoring in any logistical costs which can contribute to the overall cost of owning and electron microscope.
Configurations
It is best to remember that an Electron microscope is a highly specialized machine, that is usually bought for specific purposes so certain configurations can be elected that can affect the price.
For instance, choosing a higher contrast high resolution lens over the more common, standard lens can contribute to a noticeable cost variance.
Some transmission electron microscopes often include a configuration option that allows for a specialized triple beam system. There are also configurations that can dictate where the detector is placed that affect cost.
Some electron microscopes even offer a single or dual monitor configuration that are more geared to productivity instead of image resolution.
Customization
Various microscope manufacturers will offer all sorts of different customizations and special features that can be applied to the electron microscope.
Of course, depending on how many customizations and the complexity of them they can really start to add up and will add to the price of the microscope. Some examples of customizations are:
- Static electronic backscatter diffraction (EBSD)
- Custom design for a fully focusing WDS spectrometer
- Tensile and heating stages
- Radiation shielding known as hot cells
Sample Accommodation
One major Another factor that affects the cost of electron microscopes is sample accommodation.
Depending on the type of specimens being observed there may be special requirements regarding weight, size, ventilation, or barriers required to accommodate the specimen.
Depending on the requirements for specimen accommodation this can dictate either customizations to the electron microscope or picking a different electron microscope altogether.
Resolution
Often some high resolution electron microscopes can resolve images at around 0.18 nanometers. There are specific objective lens and imaging systems that are required to achieve these high levels of resolution and they are not cheap.
High end electron microscopes will have low kilovolt specifications that allow high resolution on specimens that are beam sensitive.
Components
There are many different components that can contribute to price differences among electron microscopes, but the majority of variation can come from these components:
- Emitter – The emitter is the source of the electrons and can come in three different types. The first type is a tungsten filament. This is the most common type of emitter and is made out of high grade tungsten. The other two types are a solid state crystal and a field emission gun.
- Detectors – In short, several detectors are used to detect scattered electrons that help to produce the electron microscope image.
- Stage controls – Stage controls allow the specimen to be rotated, raised, lowered, and tilted. Depending on the type of stage controls there may be 5 axes of control.
- Image display – Depending on the electron microscope there could be a wide variety of image displays that could come with the system. Some common configurations are large screen, single image, dual image, and quad image displays.
Advantages Of An Electron Microscope
Electron microscopy has several main advantages. These include:
- Magnification and higher resolution – as electrons rather than light waves are used, it can be used to analyze structures which cannot otherwise be seen. The resolution of electron microscopy images is in the range of up to 0.2 nm, which is 1000x more detailed than light microscopy.
- Diverse applications – Electron microscopy has a diverse range of applications in many different fields of research including technology, industry, biomedical science and chemistry. Examples of applications include semiconductor inspection, computer chip manufacturer, quality control and assurance, analysis of atomic structures, and drug development.
- High-quality images – With proper training, an electron microscope operator can use the system to produce highly detailed images of structures which are of a high quality, revealing complex and delicate structures that other techniques may struggle to reproduce.
Disadvantages Of An Electron Microscope
However, there are several disadvantages which may mean that other techniques, especially light microscopy and super-resolution microscopy, are more advantageous to the researcher. These include:
- Inability to analyze live specimens – As electrons are easily scattered by other molecules in the air, samples must be analyzed in a vacuum. This means that live specimens cannot be studied by this technique. This means that biological interactions cannot be properly observed, which limits the applications of electron microscopy in biological research.
- Black and white images – Only black and white images can be produced by an electron microscope. Images must be falsely colorized.
- Artifacts – These may be present in the image produced. Artifacts are left over from sample preparation and require specialized knowledge of sample preparation techniques to avoid.
- Cost – Electron microscopes are expensive pieces of highly specialized equipment. As most projects have limited budgets, it may prove detrimental to use an electron microscope in the research. However, running costs can be similar to alternatives such as confocal light microscopes, so the investment in a basic electron microscope is still worth considering even if budgetary concerns are a major factor in decisions against utilizing the technology.
- Size – Despite the advantages in technology over the years, electron microscopes are still large, bulky pieces of equipment which require plenty of space in a laboratory. Also, as electron microscopes are highly sensitive, magnetic fields and vibrations caused by other lab equipment may interfere with their operation. Consideration must be given to this if the researcher is looking to install an electron microscope in their laboratory.
- Training – Specialist operators are required to operate electron microscopes, and these can undergo years of training to properly use this technology.
Ever since I was a little girl, I have been fascinated by science. Every holiday I would ask for the newest science kit, and spend weeks learning with it.
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