Objects and materials that can be measured in nanometers are extremely tiny. When compared to other scales of measurement, a nanometer is one billionth of a meter. Things this tiny cannot be seen with the human eye. Advanced microscopes allow scientists to observe and even manipulate objects at the nanoscale. 


Unlike optical microscopes that use visible light to illuminate magnified objects, electron microscopes use electrons so they can magnify nanoparticles. Scanning Electron Microscopes (SEM) and Scanning Probe Microscopes (SPM) use an electron beam or tips to send scanned information to computers that produce images of nanoscale objects.


The images in the Yuck Factor category include objects that might make us squirm or look away or just say “Yuck!” In reality, they are very close-up photographs of things we might see any day, anywhere. Every year, people who own scanning electron microscopes from microscope maker FEI enter their best microscopic images in the FEI Image Contest. The images in this collection are from that contest.


About Scale

Learn how to measure the size of the objects in this collection. Click and drag to move the image in order to see the very bottom—or download the image—and note the scale bar. This bar will be different for every image. The scale is noted most often in micrometers (μm), but sometimes in millimeters (mm) or nanometers (nm). These scale bars are used much like the scale bars on maps—where one inch might equal 100 miles, for example. Use a piece of paper, a ruler, or other measuring device to determine the size of the object according to the scale on the image. Note that the scale might be indicated in millimeters, micrometers, or nanometers. Then list the images on paper, or place downloaded images in order, according to size—from largest to smallest.


About Electron Microscope Images

All images taken with electron microscopes are black and white because of the absence of light in the process. Color is added in post-processing phases.

When enlarging or cropping images with scale bars, such as the microscopic images in this collection, be sure to maintain the original aspect ratio of the image—ensuring that everything in the image is reduced or enlarged proportionally.

  • Bright red sunsets are caused by nanoparticles in the atmosphere, much of which come from volcanic eruptions.
  • The word nanotechnology comes from the Greek word nanos (dwarf) and describes the work that scientists and engineers undertake to manipulate these minute objects to make useful products.
  • Nanoscale materials have been used for over a millennium. For example, nanoscale gold was used in stained glass in medieval Europe and nanotubes were found in blades of swords made of Damascus steel. However, ten centuries passed before high-powered microscopes were invented, allowing us to see things at the nanoscale and begin working with materials at the nanoscale.
  • Nanotechnology is used in many commercial products and processes; for example, nanomaterials are used to manufacture lightweight, strong materials for applications such as boat hulls, sporting equipment, and automotive parts. Nanomaterials are also used in sunscreens and cosmetics.

system of land management combining the cultivation of both crops and trees.


metric unit of measurement, equal to about .34 inch.


a unit of length equal to one millionth of a meter—also called micron.


a unit of length equal to 11000 meter.


(nm) billionth of a meter.


length scale whose relevant unit of measurement is the nanometer (nm), or a billionth of a meter. Also called the nanoscopic scale.


distinctive relative size, extent, or degree.

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This material is based in part upon work supported by the National Science Foundation under Grant No. DRL-0840250. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.