On a bush walk more than 10 years ago we found a dead cicada, and started to ask questions about it. The trail we began to follow has now led to the discovery of materials that are self-cleaning, repel water, kill bacteria and can serve as a base for culturing cells. They may well provide the blueprint for many useful materials.
We began our investigation by exploring what the cicada surface looked like with an atomic force microscope. The wing consisted of tiny bumps of similar height spaced around 200 nm apart (Fig. 1). Why would this insect evolve such fine structuring of its wing?
We noticed that the wings didn’t seem to reflect light very well. We knew that moths had evolved similar nano-patterning on their eyes, so it seemed reasonable that the cicada structuring may serve a similar purpose. Not shining in the sunlight or moonlight would help the insect to avoid predators such as birds – a good stealth technology.
We used our instrumentation to physically scrape away...
