This is cool and great and all, but isn't it a bit ... stretched to motivate this by the fact that the nozzle is biodegradable?

I mean for a printing nozzle with an inner diameter of 20 µm, how much material would be wasted if it was made out of plastic or metal? I get that no such nozzle is available and/or easily made, but shouldn't that be the point of the invention, rather than "yay, it's biodegradable so we save a microgram of plastic/metal"?

Yes, it's silly. They surely use orders of magnitude more consumables (latex gloves, plastic bottle tops for chemicals...) in preparing a batch of mosquito proboscides than the hypothetical nozzle would take up.

The university's marketing department has been instructed to emphasize sustainability in its press releases, and the website reporting it has, like most news organisations that have survived, made the choice not to hire journalists with critical thinking skills but to have them rephrase press releases.