If you're interested in microscopes you may have heard about a device called an electron microscope: a high-powered scientific device used to create detailed images (like the image of bacteria above).

If you'd like to learn more, here are some interesting electron microscope facts, including how an electron microscope works, how electron microscopes are used, and the 4 types of electron microscopes scientists commonly use.

Electron Microscope Definition

An electron microscope is a scientific instrument. This style of microscope utilizes a beam of electrons to magnify objects for careful examination.

Electron Microscope vs. Optical Microscope

Optical microscopes are wonderful tools to magnify subjects for examination, but they are limited in that the wavelength of light restricts the maximum possible magnification. Since electrons have a smaller wavelength than light, an electron microscope can produce a higher magnification than an optical microscope. Electron microscopes can see objects around 1,000 times smaller than the smallest objects you can examine with an optical microscope.

How Do Electron Microscopes Work?

Electron Microscopes work by revealing the outline of objects via a flow of electrons. This outline is transformed into a picture scientists can examine using visible light.

Types of Electron Microscope

You may be surprised to learn that there are actually 4 kinds of electron microscope. Each serves a unique purpose for scientists.

TEM – Transmission Electron Microscope

When using a Transmission Electron Microscope or TEM, an electron beam is sent toward the object you wish to examine. Some of these electrons are reflected by the object and others pass through. The TEM’s electrons which pass through the object create an image of your specimen at a magnification of up to 5 million times its actual size.

REM – Reflection Electron Microscope

Reflection Electron Microscopes work in a similar way to Transmission Electron Microscopes. The difference (you may have guessed this already) is that REMs reveal an image of your specimen based on the electrons that are reflected. Reflection Electron Microscopes are great if you want to carefully examine the surface of an object.

SEM – Scanning Electron Microscope

Scanning Electron Microscopes, or SEMs, function differently in that a narrow beam of electrons slowly passes over the object which you are examining. A magnified image is gradually revealed based on how electrons are reflected or absorbed by your specimen as the beam passes over it.

STEM – Scanning Transmission Electron Microscope

Scanning Transmission Electron Microscopes combine the amazing surface detail of an SEM with the high magnification of a TEM. Scientists can use a STEM to perform complex analysis of a specimen which cannot be performed using a Transmission Electron Microscope alone.

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