Man’s innate curiosity has pushed humanity over many obstacles via inventions that beg the question of which type of microscope achieves the greatest resolution and highest magnification? From the invention of electricity, cars, aircraft, the internet, lens, and various engines until papers, we have always desired a better way of doing things.
As with these other inventions, seeing things smaller than the eyes can capture led to the invention of the microscope. Different types of microscope have been developed and identifying the best of all leads us to ask the question: which type of microscope achieves the greatest resolution and highest magnification?
The Invention Of The Electron Microscope
Inventions such as this must be studied in-depth. This would require knowing the inventor, in this case, inventors and contributors. Scientists and Engineers Ernst Ruska and Max Knoll developed the first-ever electron microscope in 1931.
The prototype resembled a modern light microscope in terms of similar 400X magnifying power. As a result, principles of atom and electron microscopy could be practiced and demonstrated. A bid deal in the early 1900s because these two fields were absolutely abstract and merely concepts.
Despite the success of the first electron microscope model, several individuals made attempts to create an electron microscope with few successes recorded. Ernst Ruska and German physicist Bodo von Borries kept working on improving the quality of the electron microscope until it became the powerful tool it is today.
The electron microscope’s magnification and resolution powers are unmatched, and its compatibility with different types of materials and specimens.
The Effectiveness Of Electron Microscopes
There was an age when computers had to fill an entire room before the smallest bytes of data could be processed, and over a long time at that. But now, all it takes is a MacBook or high-end gaming PC to get things done. The desire to see the innermost parts of the tiniest particles led to the invention of the microscope.
By definition, a microscope is an optical instrument that allows you to view small objects via magnification so you can see and make sense of things invisible to the human eye. Now, the electron microscope can achieve the highest resolution and magnification of all the microscopes ever built. Thus, only the electron microscope allows us to view things down to the nitty-gritty of its atom.
With this magnifying power, the electron microscope can view any material hundreds o thousands up to millions of times its actual size. That’s not all there is about this microscope; although it can zoom in and show you intricate details, it does so in a vividly clear way.
Being the only microscope with this capability, it has propelled science and technology into a new age: one filled with full access to information hidden from previous ages.
This tool breaks the rank and joins the elite group of devices that can shape our lives and understanding of the universe. And you must not be oblivious about the different types of the electron microscope, how it works, what makes it powerful, and the kind of materials you can view with it.
Types Of Electron Microscope
Electron microscopes can be grouped into three based on their different features, functionality, and capabilities. And they are:
- Scanning electron microscope (SEM): magnifies and produces resulting images from the specimen by scanning the backscattered beam of electrons.
- The transmission electron microscope (TEM): transmits electrons through the specimen and a penetrative beam of electrons is used to produce the resulting image on a screen.
- The scanning transmission electron microscope (STEM): combines the mode of operation of the other two electron microscopes.
Electron microscopes aren’t limited to these three types. There are other models developed for special functions. Some of the specially designed models include microscopes for viewing fluids, minerals, and even magnetic objects.
Furthermore, electron microscopes are combined with other technological specs for a wide range of applications. In advanced and rare cases, electron microscopes are coupled with other technological components for increased functionality.
Understanding The Workings On An Electron Microscope
The underlying principle aiding the effectiveness of electron microscope is electron microscopy. This special type of microscopy uses a concentrated beam of accelerated electrons projected onto the object to be viewed. While describing the types of electron microscopes, we discussed the dependency of this tool on electron microscopy.
However, the general rule of operation involves;
- Prepare the specimen and place it in the microscope’s vacuum chamber, where it will be bombarded with a charged beam of electrons. Preparing the specimen means they must be cut to immensely thin slices due to the microscope’s powerful magnification. The placement must be on the designated specimen holder.
- Released from an electric gun, these charged particles are projected onto the object to either scan or pass through it.
- The electron gun produces the charged electrons while two condenser lenses focus the electron beam solely onto the specimen. Afterward, the electron beam is focused into a thin tight beam.
- Since the electron has to move with the vacuum chamber, an accelerating voltage between the tungsten filament and an anode is applied, usually between 100kV and 1000 kV.
- In most cases, the charged beam penetrates the specimen, and the electron particles are dispersed based on the thickness and refractive index of the specimen.
- The thicker the specimen is, the more the electron particles are dispersed, and thus, the resulting image appears dark. However, transparent regions allow more electrons to strike that area of the screen, so the resulting image appears brighter.
- The specimen’s dispersed and penetrative electron beam is passed unto an objective lens that creates the intermediary version of the magnified image.
- The final and clearer resulting image is created by the ocular lens and made visible to your eyes when you look into the microscope.
which type of microscope achieves the greatest resolution and highest magnification?
The Power Of An Electron Microscope Explained
The magnification and resolution of an electron microscope are superior to other types of microscopes. Here, we’d look into possible reasons for this superiority; otherwise, we’d never know which type of microscope achieves the greatest resolution and highest magnification, more so, why it can.
The two possible factors for such powerful performance are
- Unique lens setup in the microscope.
- A beam of electrons it uses.
An electron microscope uses shaped magnetic fields that create different optical electron lens systems, giving the device the ability to magnify any image several times. In terms of resolution, a beam of electrons is used as a light source. When compared with visible light, electrons have a shorter wavelength which means image resolution is at the highest possible value.
How Much Detail Can You Capture With An Electron Microscope?
With an electron microscope being the most powerful magnifying tool out there, you can expect to see through virtually anything. In fact, with an electron microscope, you can view specimens at the nanoscale.
That’s not all there is because the microscope can also view any material from inorganic elements & compounds to microorganisms. This broad classification includes all plants and animals and tiny specimens like cells, viruses, and pathogens.
Therefore, you can expect to see a wide scale of intricate details with an electron microscope. The structural makeup of any specimen, nano details, properties, and behavioral patterns are all visible under the electron microscope.
Importantly, the atomic structure can be studied concerning the specimen’s reaction to the environment.
Parts Of Electron Microscope
An overview of the electron microscope is like a tall vacuum column vertical mounted, and it has the following components:
- Electron gun: a heated tungsten filament, which generates electrons projected onto the specimen.
- Electromagnetic lenses: 3 variants will be described.
- Condenser lens: which focuses the charged electron beam on the specimen to be studied.
- A second condenser lens: which condenses the beam of electrons produced by the first lens into a thin beam. Charged beams pass through a second magnetic coil (objective lens) which forms the intermediary version of the magnified image.
- The projector lenses otherwise called ocular lenses produce the resulting final image which is further magnified.
These three lenses are magnetic and help create the magnified image while keeping the clarity and resolution at the best available result.
- Specimen Holder: where you place the specimen: an immensely thin film of carbon kept in place by a metal grid.
- Image viewing and Recording System: with the aid of digital cameras and frame grabbers, the resulting final image is clearly presented on a fluorescent screen. Underneath this screen is a camera that records the image produced.
FAQs About Electron Microscope
1. How much does it cost an electron microscope?
Electron microscopes are powerful tools, and owning one can cause to be $100,000 on your savings. However, you do not necessarily have to own one before you can use one. High-end laboratories in top universities and designated professions always have one available for rental use. Although there are always strict guidelines, you have to follow them.
2. How do you operate an Electron Microscope?
Understanding how this optical works can help you operate it without any hassle.
- First, you have to obtain a sample to be viewed. Usually, micro-thin slices of the specimen are recommended.
- The Scanning electron microscope must be brought down to atmospheric pressure before you can put the specimen in place.
- Always put on gloves as a means of precaution and efficient use of the tool.
- Use the EVAC button to put the specimen in place and the chamber under vacuum. Wait a few minutes before proceeding with other steps.
- After a few minutes, release the charged electronic particles onto the specimen and take pictures.
- The sample height can be adjusted, and the zoom function can capture as many details as you desire.
- After all, turn of the electric beam, open the chamber, remove your sample and return the blank sample.
3. Is an Electron Microscope dangerous to humans?
A damaged microscope can pose a threat to human life because of radiation concerns. Backscattered electrons from the sample can escape through damaged interlocks as well as X-rays created in the process. The increased exposure can affect the unprotected human skin.
4. What Are The Radiation Safety Concerns?
As described above, backscattered electrons from the sample and x-rays are hazardous. However, electron microscopes are usually well shielded and produce exposure rates that are harmless when contained. Therefore, the integrity of the microscope’s shielding must be maintained and interlocks functioning properly.
5. Can You Use An Electron Microscope On Living Tissue?
No, because Electron microscopes project electrons on specimens, and this destroys the samples.
6. Can Electron Microscopes Produce X-Rays?
Primarily, electron microscopes do not produce X-rays. However, as the primary electron beam hit metal parts with enough energy, they are excited and behave as characteristic X-rays.
7. Can You View Anything Under An Electron Microscope?
Electron microscopes allow you to view biological samples: cells, tissues, small organisms, and even inorganic substances. Unfortunately, living samples cannot be viewed as they are destroyed in the process.
8. What Are Some Limitations Of Electron Microscope?
As beneficial as electron microscopes can be, the cost, size, maintenance are limitations to watch out for. They are large, cumbersome, expensive, and very sensitive and must be handled with utmost care.
9. Are Colors Visible Under Electron Microscopes?
Electron microscopes have only been able to produce red and green colors. However, the machine saves other unique colors as artificial, especially when a metal loses electrons.
10. Is A Light Microscope Better Than An Electron Microscope?
Electron microscopes are known to have achieved the greatest magnification and resolution. Unfortunately, they are best for viewing everything except living samples. On the other hand, light microscopes have an edge because they can study living cells at low magnification and resolution.
Electron Microscope: One Foot Towards The Future We Desire
Without a doubt, whenever you are asked which type of microscope achieves the greatest resolution and highest magnification, you know for sure that it’s the electron microscope. This powerful optical instrument is designed to give us access to microscopic details of specimens down to the atomic level.
Like the sun shines on us, electron microscopes shine charged electrons on the specimen. Asides from this, a special magnetic field in the device gives the resulting image from powerful magnification and resolution.
As a product of the mid-20th century, this powerful imaging tool has enabled advancement in science and technology. With access to information like never before, man has furthered our superiority and dominance on earth. With this invention, man has taken a step further in the direction of our desired future.