The Marriage of Art and Science: Scanning Electron Microscopy

By Joseph


As both an aspiring artist and scientist, I find special appreciation for technologies like the scanning electron microscope, or SEM.  In addition to fueling scientific discovery, the SEM illuminates the tiniest of nature’s beauties.  Although it is difficult to avoid a SEM image every once in awhile in our modern lives, I’d like to give you what I think is a top hits list.

Image courtesy Iowa State University

But first, a little background on the SEM. The SEM is a type of microscope that creates an image by bouncing electrons off an object instead of light.The microscope produces an electron beam that travels vertically through a vacuum inside of the microscope, focused along the way by electromagnetic fields and lenses.  When the electron beam hits the specimen on the stage, it causes electrons and X-rays to be emitted from the sample.  Detectors then catch these “backscattered” electrons and X-rays and convert them into an image.  As the electron beam is interacting with individual atoms in the sample, the SEM enables extremely high-resolution images.  The narrow beam of electrons is moved across the sample in successive rows, thereby “scanning” the sample.  The detector reading the “backscattered” electrons is a combination of a scintillator and photomultiplier in which the accelerated electrons cause the scintillator to emit flashes of light which are captured, amplified, and displayed by the photomultiplier.  In addition, the narrow width of the electron beam causes SEM images to have a very large depth of field, enabling images that convey the full 3-dimensional character of the sample.

Now that you have a general concept of how the images are produced, let’s take a look at what I think are the TOP 5 SEM images (note:  SEM images are black and white, so any color is “pseudo-color” applied by a computer):

Ant.  So svelte.   Image courtesy Dartmouth Electron Microscopy Facility.

Human sperm.  As the story goes, when the microscope was first invented in the 17^th century, one of the first things that was examined was human sperm (most likely of the inventor).  I’d like to think the same thing happened with the SEM.Image courtesy Science Photo Library, Barcroft Media L.

Spiny-headed worm.  Yeah this could be in your gut.  Right now.  Image copyright Museum of Science, Boston, 1996.

Mammalian lung epithelium.  Red blood cells are sitting on top of ciliated and non-ciliated bronchiolar cells.  Image courtesy Dartmouth Electron Microscope Facility.

Human eyelashes, mostly awesome because they look gross.  Image courtesy Science Photo Library, Barcroft Media L.


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