What is an electron microsope?
A kind of biology microscope that utilizes electrons in order to iluminate and make the image of the specimen that is being observed through the eyepiece is called an electron microscope. Its magnification is higher and more powerful than the average optical microscope.

An electron microscope can also let one see minute objects in much greater detail because it utilizes glass lenses in order to focus the light. It also uses electromagnetic and electrostatic lenses in controlling the imaging and illumination of the subject that is being observed.

History of the electron microscope
In 1931, the first prototype of the electron microscope was built by the engineers Max Knoll and Ernst Ruska of Germany. It was inspred by the discoveries of Louis de Broglie, a French physicist who first presented the idea of the microscope. It might have been quite primitive and impractical, but the electron microscope of 1931 could still magnify objects 400 times greater than usual.

The same year, Reinhold Rudenberg, Siemens research director, filed for the patent of the electron microscope. Siemens started funding Ruska and Bodo von Borries in developing an electron microscope in 1937.

In 1938, the first electron microscope was built in the University of Toronto by students Cecil Hall, James Hillier and Albert Prebus and their professor Eli Franklin Burton.

Kinds of Electron Microscopes

1. Transmission Electron Microscope

Abbreviated as TEM, this original kind of electron microscope which utilizes electrons of high voltage beams that are emitted by the cathode. The cathode is generally a flimant that contains tungsten. It focuses the electromagnetic and electrostatic lenses. The beams of electrons that have been transmitted into the specimen being observed is transparent to the electrons that carry the information into the inside structure of observed specimen. The electron beam brings images into the microscope system.

The image is magnified through the electromagnetic lenses and is recorded in the flourescent screen. The image may be detected by the device cameras that are couply charged. There are some transmission electron microscopes that are hooked into the PC. These kinds of microscopes make it easier to upload the image into the computer.

The resolution is limited to the spherical abberation. However, aberration correctors were invented  in order to overcome the problem and to also increase the resolution. Some software has also been created in order to project the image in the Highest Resolution possible.

2. Scanning Electron Microscope

Abbreviated as SEM, the electrons in the beams of high voltages complete the image of the subject that is being observed. It produces the images that are detected through the lower energy and seconday electrons which have been emmited form the specimen’s suface because of the premiere electron beams.

The electron beams in SEM is plastered across the specimen being observed and the detectors create an image that is mapped out in such a way that detects the signals of the positions of all the beams.

The resolution in the TEM may be more powerful than the SEM however the images that are projected from the SEM has a surface process that is easily transmitted by bulks. The SEM also has a greater view of the specimen and can produce the images and represent this in a 3D manner.

3. Reflection Electron Microscope

Abbreviated as REM, this is similar to the TEM because the process used is the involvement of the electron beams that are evident on the suface. Howeveer, unlike the SEM and the TEM, the beam being reflected is easily detected in the REM. This is then partnered up with the Reflection High Energy Electron Diffraction which promotes the energy loss of the spectrum in the REM.

4. Scanning Transmission Electron Microscope

Abbreviated as the STEM, this combines TEM’s hgh resolution and SEM’s rastering function. With this, it lets in the analytical technique that is not possible in the other electron microscopes.

Disadvantages of Electron Microscopy

First and foremost, electron microscopes are quite expensive to purchase. Not only that, they are also expensive to maintain. Yes it is true that these are dynamic and not static in their conducted procedures, however these microscopes require high-voltage supplies. Not to mention the fact that every electromagnetic lens must be continuously pumped up. Cooling water must also be continuously supplied.

The specimen must also be viewed in the vacuum because the air can built up particles that will affect the molecules of what will be observed. Recent studies show that electron microscopes lessen the chances of this happening because it only lets in the hydrated samples after scanning it.

Those who wish to purchase electron microscopes and get into electron microscopy must observe each detail. Simply because, the sample must be prepared in ways that will allow it to promulgate in the best way possible.