Scanning Electron Microscopes (SEM)

How Does a Scanning Electron Microscope Work?

A scanning electron microscope (also commonly abbreviated as SEM) uses beams of electrons to create magnified images of samples, as opposed to beams of light that a traditional microscope uses. SEMs use electrons that are bounced off near the surface region of a sample. Because the wavelength of electrons is notably smaller than that of light, the resolution of SEMs is greatly superior to that of a light microscope.

What Are Scanning Electron Microscopes Used For?

Because the SEM can magnify a sample up to 500,000 times its normal size and determine its chemical makeup, scanning electron microscopes have a wide range of applications. They are used for quality control in both the pharmaceutical and semiconductor industries, sample comparisons in forensics, diagnostics in medical labs, and in research labs to determine the composition of samples treated in different ways.

What Types of Scanning Electron Microscopes Are There?

Scanning electron microscopes have different kinds of signal detectors available that include back-scattered electrons (for imaging), characteristic X-rays (for determining types and amounts of elements present in the sample), transmitted electrons, and cathodoluminescence. Other variations in different scanning electron microscopes include availability of low or high vacuum mode and imaging options for bright field samples and/or dark field samples.

Check out this article "Integrated SEM Workflow Creates Powerful 'Nano-lab' " to see more ways in which SEM can be a valuable tool for your lab.