When the drone flies onto a flower, pollen grains stick lightly to the gel, then rub off on the next flower visited.
Scientists in Japan have now designed a small drone - that actually looks nothing like a bee - capable of picking up pollen from a lily and depositing it at another lily flower by using a particularly sticky gel, they report in a paper published in the journal Chem. This pollen exchange in different parts of flowers is what allows the plants to form seeds. Expanding the scope of the project from one tiny drone pollinating a large flower to a giant fleet of robotic pollinators would be challenging. Just last month and for the first time in USA history, the rusty patched bumblebee that was so prevalent two decades ago officially became a struggling bunch.
Still, despite the urgency posed by climate change and other threats to insect pollinators, some experts believe artificial methods would be less effective and economically feasible to preserve bee populations. The hope is that someday an automated version of this robot could be used to cross-pollinate crops. One of his attempts generated a gel as sticky as hair wax, which he considered a failure. Clearly this wouldn't do, and so Miyako stuck it in a storage cabinet in an uncapped bottle. But it clearly portends for a future with whirring machines flitting from bloom to bloom - though Miyako envisions bumblebots as giving bees an assist, not replacing them altogether.
"I was so surprised, because it still had a very high viscosity", Miyako said.
The next step to robo-bees required a flying object, so the team bought a tiny $100 drone with four propellers and placed a strip of coarse bristles to mimic the fuzziness of bee hairs.
They collected ants and put a drop of the substance on their bodies and let them roam free in a box of tulips. As it was expected, ants with the test material on their back gathered much more pollens than those without gel.
The gel-coated hairs created more surface area with which to pick up pollen. To find out, researchers ordered a small drone online and souped it up with a strip of fuzz made from a horsehair paintbrush covered in a sticky gel.
"A certain amount of practice with remote control of the artificial pollinator is necessary", the study authors noted.
Critics aren't so convinced pollinating drones is the best solution to the worrying bee crisis.
"In combination is the best way", he says. Miyako also said "it will be perfectly feasible" to pollinate plants with a drone, but it still needs improvements, such as high-resolution cameras, Global Positioning System and maybe artificial intelligence, which could be hard to implement on a small airborne robot.
There's a lot of work to be done before that's a reality, however.