Sometimes the most innovative solutions to technological problems are hiding right under our noses, or rather, in our own backyard. This is the case of leafhoppers, common insects which produce mysterious particles called brochosomes. These tiny jewels of nature could be the key to developing revolutionary optical materials, come on invisibility devices to coatings to capture solar energy more efficiently.
A team of researchers from Penn State University has shed light on the secrets of brochosomes, paving the way for a new generation of bioinspired technologies.
The magical anti-reflection “balloons”.
Imagine a tiny hollow sphere, just 600 nanometers in size (about half the size of a bacterium), with a surface dotted with 200 nanometer holes. A marvel of natural engineering: it is the brocosome, the particle produced by leafhoppers to cover their body.
But what are these strange, microscopic "balloons" for? For decades, scientists have puzzled over this question. Some hypothesized that they were used to keep insects clean, others to make them water-repellent.
Today, thanks to the work of the team led by professor Tak Sing Wong, we have a surprising answer. Brochosomes are a very sophisticated anti-reflex system, capable of absorbing up to 94% of incident light!
Leafhoppers: invisible to predators (and not only)
Why on earth should leafhoppers worry about reflecting light? Simple: to avoid being seen by predators. Many animals that hunt these insects, such as birds and reptiles, have vision that extends into the ultraviolet. And guess what? Brochosomes are perfect for absorbing precisely UV wavelengths, making leafhoppers practically invisible to their enemies.
But that's not all. The researchers found that the size of the holes on the surface of the brochosomes is also crucial for dispersing visible light, creating a sort of all-round "anti-reflection shield". In short, thanks to these prodigious particles, leafhoppers can literally "disappear" from sight. Feel it too that good smell of biomimetics, True? The science that "copies" nature's ingenious solutions to solve engineering problems. I'm crazy about it.
From buzzers to the technologies of the future
I know, someone (who paradoxically perhaps won't even read the article, stopping at the headlines on social media) will say: all very fascinating, but what does it have to do with us humans? Well, very much. Understanding the mechanisms underlying the optical properties of leafhopper brochosomes could pave the way for myriad technological applications.
Think of devices that can make us invisible, just like the invisibility cloaks in the Harry Potter films. Or super-efficient coatings for solar panels, which capture light without reflecting it. And what about ultra-powerful sunscreens, or optical encryption systems, where data is only visible under certain wavelengths? The possibilities are practically endless.
How to build artificial brochosomes?
Before they could fully exploit the potential of brochosomes, researchers had to overcome a significant obstacle: being able to replicate them in the laboratory. Their geometry is so complex that reproducing them has long been a puzzle for scientists.
But the Penn State team didn't give up. Using highly advanced 3D printing techniques they managed to create synthetic "photocopies" of brochosomes, enlarged 20.000 times compared to their natural size (about a fifth of the diameter of a human hair). A true masterpiece of "reverse engineering", which allowed the optical behavior of these particles to be studied in detail.
In short (Italian only)
As emphasized Lin Wang, first author of the study (that I link to you here), nature is an incredible teacher for materials scientists. Leafhoppers are just one of many examples of animals that hold precious secrets for technological innovation. “It's not just insects,” Wang says. “I am a source of inspiration.”
Behind the tiny body of a leafhopper lies a marvel of optical engineering, the result of millions of years of evolution. A prodigy that, who knows, one day could give us technologies worthy of a science fiction film.
