This weekend was the Cincinnati Museum Center's annual BugFest. Together with my son Cameron we had a great time showing visitors a sampling of butterflies from the zoology department's entomology collection (see photo left). Public presentations of museum collections should introduce the role of museum collections in scientific research. Museum collections and other collections-based field work can have uses that will come as a surprise to many. Focusing on butterflies Cameron and I chose to present the role collections can play not only in gaining a basic understanding of nature but also their potential role in very practical applications in materials science.
High magnification images of the wing of a Morpho butterfly were fed to an LCD screen and used to show visitors the intricate scales that make up a butterfly wing. The very fine micro-structure of these wing scales is what creates the iridescent blues and greens of butterfly wings. While many colors in nature are due to pigments embedded within biological structures like hair, feathers or scales other colors are purely structural created by the particular scatter of light reflected from a structured compound like keratin in birds' feathers or layers of chitin in insect scales. Many blues and greens in bird feathers and insect scales tend to be determined by structure rather than pigments. The very fine microscopic structure of a blue feather or scale therefore determines the wavelengths of light it reflects and thus it's color.
Believe it or not a knowledge of how nature produces colors is useful in nanotechnology. Nanotechnology deals with the engineering of very tiny machines on the size scale of a cell. Mimicking nature can be very useful in producing components for these tiny nano-devices. Butterfly wing scales are studied by engineers to create nano-parts with very particular optical properties. Jingyun Huang et al. in 2006 in the journal Nano Letters found that the wing scales of the iridescent blue butterfly Morpho peleides could be used as a template for making tiny artifical scales of aluminum oxide. These artificial aluminum oxide butterfly scales had identical reflective properties to their natural counterparts and they could be used in nanotechnology to split beams of light. Radislav Potyrailo et al. in the journal Nature Photonics in 2007 published a paper describing the ability of the wing scales of Morpho sulkowskyi to act as components in tiny optical gas sensors.
Of course museum collections act as accessible storehouses of biological diversity and the holdings in collections, like those at Cincinnati Museum Center, can provide material for numerous applications (many of which would have never been anticipated by the original collectors) in both basic and applied research.
Potyrailo, R.A., Ghiradella, H., Vertiatchikh, A., Dovidenko, K., Cournoyer, J.R., Olson, E. (2007). Morpho butterfly wing scales demonstrate highly selective vapour response. Nature Photonics, 1(2), 123-128. DOI: 10.1038/nphoton.2007.2
Huang, J., Wang, X., Wang, Z. (2006). . Nano Letters, 6(10), 2325-2331. DOI: 10.1021/nl061851t