Butterfly wings have already inspired engineers looking for advances in optical surfaces that can reflect brilliant colors (see here). Now they are inspiring materials scientists wanting to create better waterproof surfaces for electronics.
An article on Science Daily, “Butterfly Wings Inspire Design of Water-Repellant Surface” (note the word “Design”), begins:
The brilliant blue wings of the mountain swallowtail (Papilio ulysse) easily shed water because of the way ultra-tiny structures in the butterfly’s wings trap air and create a cushion between water and wing. Human engineers would like to create similarly water repellent surfaces, but past attempts at artificial air traps tended to lose their contents over time due to external perturbations. [emphasis added]
A team of scientists from South Korea, Sweden and the U.S. has now succeeded, the article continued, by etching tiny geometric shapes in a silicon substrate that can trap air for more than a year: “The intricate structure of pores, cones, bumps, and grooves also succeeded in trapping light, almost perfectly absorbing wavelengths just above the visible range.”
The new design thus mimics two advantages of butterfly wings: optical enhancement and water resistance. The team’s new “biologically inspired surface … could find uses in electro-optical devices, infrared imaging detectors, or chemical sensors,” the article boasted. Now, if they can get it to find its own energy, lay eggs and resist damage when flapping in the wind, they’ll really be onto something.