Someone pointed me to this interesting article on pigment vs structural coloring found in the animal kingdom.
Blue Animals Are Different from All the Rest
https://www.theatlantic.com/science/arc ... ay/619243/
The last paragraph cites a paper in Nature Photonics on an improved method of dark-field imaging microscopy inspired by the nanoscale grooves in the wing scales of butterflies. The full text of the paper, which describes using a luminescent micropatterned photonic surface to provide darkfield illumination particularly useful at higher magnifications, can be found at:
Luminescent surfaces with tailored angular emission for compact dark-field imaging devices
https://bioinspiredoptics.mit.edu/wp-co ... missio.pdf
"Here, we propose to simplify and miniaturize dark-field microscopy instrumentation by integrating the dark-field light source into the sample substrate. . . We call this dark-field imaging technique,
which relies on the unique light-emission characteristics of the substrate, ‘substrate luminescence-enabled dark-field’ imaging (SLED)."
Interesting stuff.