Mosquito inspired injection

How would medical researchers build the perfect needle, for sensitive injections or brain-tissue sampling? Of course, they’d look to nature.

And where in nature would they find the perfect needle? On the sharp end of a mosquito!

Mosquitoes are the most dangerous creatures on Earth, carrying diseases that infect 700 million people a year and kill 2 million.

This is because, for millions of years, they’ve been so good at sticking their beaks into us.

They do this with a special six-part proboscis:

There’s a pair of maxillae, tiny serrated blades that vibrate to quickly saw into the tissue. A pair of mandibles holds the tissue apart as the maxillae cut, so they can continue deeper.

A tubelike hypopharynx injects saliva, which contains a numbing agent, an anticoagulant, and a blood-vessel dilator. And a V-shaped labrum draws up the blood.

Scientists analyzed these parts, then set out to copy them.

They built tiny saw blades of glass crystals and vibrated them with a piezo motor, like in a wristwatch. Two tiny needles held the puncture apart, while a third, ultrafine needle made the injection or drew the sample.

These are lubricated with a topical anesthetic and constructed to be flexible like a mosquito’s proboscis, which reduces the pressure at the puncture site by 30 percent.

The result is a completely painless microneedle for the most sensitive uses—a comforting gift from that most bothersome insect.