In Part 1 of this series, I discussed the giant Arapaima fish which is inspiring better designs for body armor. In this episode, we leap from the fresh waters of the Amazon and other parts of the world to the skies of southern and southeast Asia, to learn about how butterflies are providing their own source of inspiration.
In the BBC podcast series “30 Animals That Made us Smarter”, butterflies are (so far) featured not once, but three times. The first two:
- Paint and textiles inspired by the Blue Morpho butterfly
- Butterfly eggs inspiring architectural designs from the White Royal butterfly
This episode, however, is about biomimicry threaded through a project to significantly improve solar panel efficiency thanks to the Common Rose butterfly, featured in the top photo in the blog post.
So - what’s the story here?
Butterflies have no way to generate heat internally – they are cold-blooded. They are constantly ‘harvesting’ solar energy – it’s a heat tactic to warm up their internal temperature. California Institute of Technology scientist Radwanul Hasan Siddique explains, in the paper, “Bioinspired phase-separated disordered nanostructures for thin photovoltaic absorber”,
“The nanopatterned absorbers achieve a relative integrated absorption increase of 90% at a normal incident angle of light to as high as 200% at large incident angles, demonstrating the potential of black butterfly structures for light-harvesting purposes in thin-film solar cells.”
This team was able to create the structure organically – creating plastics which naturally organize itself into a lattice structure. Doubled the amount of light collection, especially at “off angles” or indirect sunlight.
Below you can see figures depicting the process, and a closeup of the structure – something that is not an ‘obvious engineering solution’ – something we’re taught about from …butterflies:
Could your project use some bio-inspiration? Check out the podcast, 30 Animals That Made Us Smarter!
Overall source: R.H. Siddique el al., "Bioinspired phase-separated disordered nanostructures for thin photovoltaic absorbers," Science Advances (2017). advances.sciencemag.org/content/3/10/e1700232