Mankind’s innate curiosity and our desire to learn and grow has continuously pushed us to figure out better ways of doing things, and this includes being able to see things smaller and smaller, hence the invention of the microscope.
The definition of a microscope is a piece of optical instrument that is designed to view very small objects by magnifying it several times, so that its details that are not visible to the naked eye can be seen and analyzed.
But, which of the many different types of microscopes does this task best? Which microscope achieves the highest magnification and greatest resolution?
The electron microscope
Out of all types of microscopes, the electron microscope has the greatest capability in achieving high magnification and resolution levels, enabling us to look at things right down to each individual atom.
This microscope has the power to magnify almost any type of material for hundreds of thousands up to millions of times, and has the resolution of less than a single nanometer, far superseding any other microscope out there.
It’s the only microscope that is equipped with this kind of power, which allows us to see things that have never been seen before, and therefore propelling science and technology into a whole new era filled with new information and tools that shape our lives and our understanding of the universe.
When was the electron microscope invented?
The first-ever electron microscope was invented in the year 1931 by a pair of scientists and engineers named Ernst Ruska and Max Knoll. This prototype worked similar to a modern light microscope, with a magnification power of 400 times.
This enabled the first-ever physical demonstration of the principles of atom and electron microscopy, fields of study which were then only mere concepts. Several other attempts by other individuals were made to create an electron microscope, some of which were successful.
For the succeeding years, the electron microscope was continuously developed and improved, led by Ernst Ruska, until it became capable of reaching the magnification and resolution powers that it boasts of today, as well as compatible with most types of materials and specimens.
How does the electron microscope work?
The basic underlying principle of electron microscopes is a special type of microscopy aptly named as electron microscopy. This makes use of a concentrated beam of accelerated electrons that are projected onto the specimen being viewed.
The exact process is dependent on the type of electron microscope, but the general rule is that the specimen is prepared and placed inside a vacuum chamber, and is bombarded with charged electrons.
These electrons come from an electron gun and are transmitted to the specimen so it can either scan the specimen or pass right through it much like how a light microscope works. The electrons then get tracked by a detector, which is what creates the magnified image.
What makes an electron microscope powerful?
Electron microscopes have an exceedingly high magnification and resolution superior to any other microscope, and this is made possible by two things- the microscope’s special lens system, and its use of electrons.
What makes electron microscopes able to achieve such a high level of magnification is its use of shaped magnetic fields that create special optical electron lens systems, which magnify the specimen image hundreds of thousands of times.
Meanwhile, when it comes to resolution, electron microscopes use a beam of electrons to act as its “light source”, since electrons have the capability to behave like as waves, and when they do, these electrons have a wavelength that is thousands of times shorter than that of visible light.
What can you see with an electron microscope?
Since electron microscopes achieve the highest magnification and greatest resolution, there is virtually no limit as to what can be seen through it. In fact, electron microscopes are often used to look at materials at the nanoscale.
What makes this even better is that these microscopes can be used to image almost any type of material ranging from organic microorganisms to inorganic compounds and elements, which include a variety of plant and animal life, minute specimens such as cells, viruses, and pathogens, as well as chemicals and particulates.
Hence, a wide variety of microscopic and nanoscale details can be seen such as the structural makeup of the material, its properties and behavior, its reaction to its environment or with another material, and most importantly, its atomic structure.
What are the types of electron microscopes?
There are actually three main types of electron microscopes, each with different features, functions, and capabilities. These are the scanning electron microscope, the transmission electron microscope, and the scanning transmission electron microscope.
The first one works by scanning the emitted electrons of three-dimensional specimens, while the second one transmits electrons through the specimen and imprints its image onto a screen. The last type of electron microscope is a unique combination of the first two.
Apart from these three, there are many other variations of electron microscopes that are designed for specific purposes, such as for studying liquids, gasses, minerals, and magnets. An electron microscope may also be combined with other technologies to improve its function.
Overview
The microscope that can achieve the highest magnification and greatest resolution is the electron microscope, which is an optical instrument that is designed to enable us to see microscopic details down to the atomic scale (check also atom microscopy).
Electron microscopes function by utilizing electron beams that are shined on the specimen. This, coupled with special magnetic field formed lenses, is what gives electron microscopes its superior magnification and resolution power.
This powerful imaging tool is a product of the mid 20th century and has evolved so far to allow us to view almost any type of material imaginable, as well as observe things and gather the information that we have never been able to do so before. It’s also highly adaptable and compatible with a variety of tools, techniques, and devices that can further improve its ability.