Shrimp shells are a waste product of the fishing and aquaculture industries. But they are far from useless! Shrimp shells mainly consist of a compound called chitin, made up of tiny rod-shaped nanocrystals which can be extracted and purified using acid. Remarkably, these chitin nanocrystals can assemble, by themselves, into twisting helix-like shapes when put in water under the right conditions.
This is an image of a cross-section through a thin layer of these self-assembled chitin nanocrystals, taken with a scanning electron microscope. The scale bar, in the bottom right corner, is 50 millionths of a metre long, roughly the width of a human hair. With the help of magnetic fields, these helical nanocrystals structures can better align to form large and uniform regions, or domains, of neatly ordered helices. We can see the results of this well-aligned structure in the microscope image, in the form of clear, even layers between each turn of the helix. Here, in this image, because of the imperfect break of the material, we can see both parallel layers in the right bottom, as well as the gentle arches from an angled cut in the upper-left corner.
See, we can all be a nanoscale architect building amazing structures.