The printing dead

They’re quite a bit cheaper than manufactured nozzles if you can dissect them.

Necrobotics is a field of engineering that builds robots out of a mix of synthetic materials and animal body parts. It has produced micro-grippers with pneumatically operated legs taken from dead spiders and walking robots based on deceased cockroaches. “These necrobotics papers inspired us to build something different,” said Changhong Cao, a mechanical engineering professor at the McGill University in Montreal, Canada.

Cao’s team didn’t go for a robot—instead, it adapted a female mosquito proboscis to work as a nozzle in a super-precise 3D printer. And it worked surprisingly well.

Fangs and stings

To find the right nozzle for their 3D necroprinting system, Cao’s team began with a broad survey of natural micro-dispensing tips. The researchers examined stingers of bees, wasps, and scorpions; the fangs of venomous snakes; and the claws of centipedes. All of those evolved to deliver a fluid to the target, which is roughly what a 3D printer’s nozzle does. But they all had issues. “Some were too curved and curved for high-precision 3D printing,” Cao explained. “Also, they were optimized for delivering pulses of venom, not for a steady, continuous flow, which is what you need for printing.”

Continuous flow optimization, on the other hand, was a feature of some proboscises, the tube-like mouth parts some insects use to draw blood from their prey. These, the scientists found, were usually very thin and robust to enable piercing through thick skin and straight to make feeding easier. That’s why the final choice of nozzle donors came down to a decision between tsetse flies, sandflies, aphids, bed bugs, assassin bugs, and female mosquitoes. The mosquitoes ended up winning the competition.

The researchers found the female mosquito proboscis has an inner diameter measuring 20–30 microns, far smaller than most stingers or fangs, and it had a straight, long structure, making it easy to align as a nozzle. “It’s also stiff and strong, which allows it to withstand printing pressures,” Cao said. The only problem left was building a 3D printer around it.

Necroprinting

Cao and his colleagues called the device they created a “3D necroprinter.” It was based on an Aerotech precision motion stage, a mechanical positioning system that can move the printing head with ten-nanometer resolution over a stable, vibration-isolated platform. The extrusion mechanism itself was simple: a syringe-based direct ink writing system that pushed their printing material through a small plastic tip.

“To integrate the proboscis, we first removed it from an already euthanized mosquito under a microscope,” Cao explains. Then the proboscis/nozzle was aligned with the outlet of the plastic tip. Finally, the proboscis and the tip were bonded with UV-curable resin.

The necroprinter achieved a resolution ranging from 18 to 22 microns, which was two times smaller than the printers using the smallest commercially available metal dispensing tips. The first print tests included honeycomb structures measuring 600 microns, a microscale maple leaf, and scaffolds for cells.

But there were still areas in which human-made technology managed to beat Mother Nature.

Glass and pressure

The first issue with mosquito nozzles was their relatively low resistance to internal pressure. “It was impressive but still too low to accommodate some high viscosity inks,” Cao said.

These inks, which look more like a paste than a typical fluid, hold shape better, which translates into more geometrically accurate models that do not slump or spread under their own weight. This was a problem that Cao’s test prints experienced to an extent.

But this wasn’t the only area where human-made technology managed to beat nature. While mosquito nozzles could outperform plastic or metal alternatives in precision, they could not outperform glass dispensing tips, which can print lines below one micron across and withstand significantly higher pressures.

The researchers already have some ideas about how to bridge at least a part of this gap, though. “One possible solution is to use mosquito proboscis as the core and coat it with ceramic layers to provide much higher strength,” Cao said. And if the pressure problem is solved, the 18–22 microns resolution should be good enough for plenty of things.

Cao thinks that in the future, printers like this could be used to print scaffolds for living cells or microscopic electronic components. The idea is to replace expensive, traditional 3D printing nozzles with more affordable organic counterparts. The key advantages of mosquito nozzles, he says, are low cost and ubiquity.

Mosquitoes live almost everywhere on Earth and are easy to rear. The team estimates that organic 3D printing nozzles made from mosquito proboscises should cost around 80 cents; the glass and metal alternatives, the researchers state in the paper, cost between 32 and 100 times more.

“We already started doing more research on mosquitoes themselves and hope to develop more engineering solutions, not only to leverage their deceased bodies but also to solve practical problems they cause,” Cao said.

Science Advances, 2025. DOI: 10.1126/sciadv.adw9953

Jacek Krywko is a freelance science and technology writer who covers space exploration, artificial intelligence research, computer science, and all sorts of engineering wizardry.