2008-04-25

Thanks to my university's annual SEM image competition, I had the rare opportunity to use a scanning electron microscope for fun.

One of the things I was curious to see under the microscope was the protein powder I use to supplement my mostly-vegetarian diet.

In order to predictably interact with the microscope's electron beam, the sample had to first be secured with an electrically conductive adhesive and then coated in gold:

The microscope stage slides into a vacuum chamber on a vibration damped workbench. I'm told that at high zoom levels the image can still be distorted by people walking around the building, so sensitive work is scheduled after-hours.

The electron beam scans quickly enough that a low resolution image can be displayed in near–real time. At the lowest zoom level, the entire stage is visible:

Zooming in to an approximately 2-mm wide view, the protein powder begins to appear heterogeneous, like a field of debris:

In the center is something that looks like a cell. It's about 100 μm in diameter, and littered with the shattered pieces of something shell-like:

Returning to the 2-mm wide view, a crystal stands out:

It's about 300 μm long:

At a 100-μm wide view, more of the shattered fragments are visible. For the next images I tried increasing the resolution of the scan. The results are clearer, but each image takes several minutes to capture.

Looking around more, most of the powder is comprised of these rounded, globular clumps. This 100-μm long piece has been broken open to reveal air bubbles:

Time is short on the electron microscope, so that's all I was able to capture of the protein powder. I'm not sure what to make of it, but I'm quite thankful for the experience.