Butterflies may be fascinating beacons of springtime but they are more than just fluttering insects. Researchers say they have identified specialized behaviors and wing scales in these organisms which equate to living parts in the wings. These wing scale nanostructures could be a great source of inspiration for radiative-cooling materials that scientists believe could help develop excessive heat management strategies.
Study co-lead investigator Nanfang Yu explains, “Butterfly wings are essentially vector light-detecting panels by which butterflies can accurately determine the intensity and direction of sunlight, and do this swiftly without using their eyes.”
The Columbia Engineering associate professor of applied physics goes on to describe how butterfly wings are made up of a relatively complex network of living cells whose function requires a restricted temperature range in order to effectively operate. This small thermal capacity can cause butterfly wings to rapidly overheat in the sun when they stop flying. But it can also cause them to cool down too much when flying in a colder environment.
For this experiment, Yu’s lab designed a noninvasive technique using infrared hyperspectral imaging. This process isolates each pixel of an image to represent an entire infrared spectrum which enabled them to make accurate measurements of temperature distribution over butterfly wings for the first time. Indeed, this is the first study to explore the relevant implications of how temperature can shape wing structure and the overall behavior of butterflies.
Study co-leader Naomi E Pierce discusses how the team has determined that butterflies have a “wing heart”. This androconial organ, so to speak, beats several dozen times every minute, facilitating the directional flow of blood (hemolymph) through what equates to a “scent pad”.
The Harvard University Hessel Professor of Biology in the Organismic and Evolutionary Biology Department and Museum of Comparative Zoology Curator of Lepidoptera goes on to say, “Most of the research on butterfly wings has focused on colors used in signaling between individuals. This work shows that we should reconceptualize the butterfly wings as a dynamic, living structure rather than as a relatively inert membrane. Patterns observed on the wing may also be shaped in important ways by the need to modulate temperatures of living parts of the wing.”
The results of this study have been published in the journal Nature Communications.