Using an electron microscope and a high-resolution 3D printer a team from Leiden University imaged and then constructed the vessel as part of research into potential designs for vehicles that could travel inside the human body, for example to administer medical treatments.
It is a tiny copy of the “Benchy” boat, a test structure often used to test the effectiveness of 3D printers.
“We focused a laser inside a droplet,” Daniela Kraft, a physicist at the Dutch university told CNN. “If we move the laser through the droplet, we write the structure that we want,” she explained. “For example, if we move it in a helix, we are writing a helix.”
The boat was just one of many structures created by the researchers conducting investigations into microswimmers: small particles that can move through fluids, and be followed by a microscope.
Biological microswimmers are microorganisms that propel themselves, including bacteria, algae and sperm.
Synthetic, self-propelled microswimmers could have a range of uses, including delivering drugs in the human body, Kraft told CNN.
Experts created several shapes, including a spiky sphere, a starship, a spiral, a helix, a trimer and and a 3D Benchy boat.

Researchers conducted the study, published in the Soft Matter journal, to understand how certain shapes of synthetic self-propelled microswimmers affected motion and traction, and better understand the behavior of bacteria. Experts were able to create objects measuring just 4 micrometers. One micrometer is equal to 0.001 mm, or about 0.000039 inch.
“We hope to learn about what is now a good design principle for creating a little drug delivery vehicle — if you have a little particle that goes to a specific part of the body to deliver drugs, then it has to propel itself, and it may have to deal with the environment in your body, which is very complex,” Kraft told CNN.
“What we are trying to answer is: what would be a good design? What would be a great shape so that it can go around and be efficient?”
Kraft told CNN that particles created in a helix shape showed promising movement.
“When it moves forward, often it needs to rotate, and that helps, for example, to speed it up. If you think about applications, if you want to have a little machine that goes somewhere, it might be more useful to have a helix shape, because it swims faster,” she said.