BACTERICIDAL INSECT WINGS

INSECT WING NANO-KNIVES

Most flying insects have wings with waterrepellent qualities, made possible by tiny knife-like structures that sluice water away from them while they’re in flight.

“That’s quite important,” says Eser Akinoglu, a physicist at the Centre of Excellence in Exciton Science. “If water droplets adhere to the wings, then the weight of that water droplet is quite substantial in comparison to the weight of the insect itself, so it wouldn’t be able to fly.”

A scanning electron micrograph

(inset) of a cicada’s wing at 300,000x magnification reveals hexagonally spaced pillars that cause water droplets to bounce several times before sliding away – the perfect natural self-cleaner. Any bacteria not washed away are penetrated by the nanopillars and killed in three to five minutes. Fast, lethal and ripe with potential. Akinoglu and his team hope to harness this ability to create coatings for surgical implants that prevent bacteria.

Bacterial build-up (known as “biofilm”) on surgical implants is extremely hard to treat, often requiring revision surgery, which has a mortality rate of around one in every 50 patients.

This isn’t the first time these structures have inspired technological solutions.

In 2017, a team of French and American scientists created a material that had natural anti-fogging properties based on the hydrophobic nano-knives on cicada wings.

Bactericidal abilities vary from insect to insect. Dragonflies have nano-knives with great medical potential: they’re so strong they can rupture the usually unbreakable, jelly-like skins of grampositive type bacteria – a group including Staphylococcus and Streptococcus.