The tiny boat is only 30 micrometers long; about a third the thickness of a hair.

Researchers from Leiden University have built a boat. But not just any one: a miniscule small specimen. The boat is so unique that it is even the smallest 3D-printed ship in the world. So we cannot go out into the ocean with it. But the boat can provide us with many new insights about so-called “microswimmers”.

The micro boat

The micro boat is incredibly small: from bow to stern, this boat measures only 30 micrometers. For your own imaging, that’s about a third the thickness of a hair. With this size, the researchers set a real world record. Because no one has ever succeeded in manufacturing such a small boat using a 3D printer.

Photo from 3DBenchy; the tiny boat that measures only 30 micrometers from bow to stern. Image: Leiden University

As you can see in the picture above, the boat looks like a normal ship. Moreover, it can really sail, the researchers say. “We called the boat 3D benchy,” says Leiden researcher Daniela Kraft in an interview with Scientias.nl. “It has a very challenging design. The house is hollow and the chimney is very small. ”

3D printer

The researchers manufactured the boat using a 3D printer. 3DBenchy is a standard 3D design, intended to put 3D printers to the test. “We wanted to know if our printer would be able to make swimmers a few micrometers tall,” explains Kraft. The team used the new Nanoscribe Photonic Professional printer. And as the end result shows, the researchers have succeeded brilliantly.

Microswimmers

The miniscule boat is part of an experimental study of so-called microswimmers. These are small particles that move in the water and that you can follow with a microscope. One of the goals of the research is therefore to better understand the behavior of biological microswimmers, such as bacteria. For example, researchers want to clarify how bacteria move. “I find microswimmers fascinating,” says Kraft. “I would like to understand how their shape affects their behavior. The shape, for example, seems to be important for their individual locomotion, for example to get close to food or light sources. ”

Swarm

But that’s not all. “Their shape is also important to their collective behavior,” Kraft continues. “For example, bacteria form so-called ‘swarms’ in which they swim together to a new place. Their shape seems to make this movement more efficient. ” Yet we do not yet know the details. “We can therefore best investigate these questions with synthetic swimmers,” Kraft emphasizes. “In that case we don’t have other active mechanisms with which to adjust their movement. Moreover, we can investigate non-equilibrium systems with synthetic microswimmers. ”

Drive

The researchers made different shapes swim during their experiments. In addition to the special boat, they also printed microscopic wokkels that turn like a screw while they are propelled. “The screws were quite fast compared to the other shapes,” says Kraft. Neither of these shapes used moving parts. “They are all powered by a chemical reaction, which is to convert hydrogen peroxide (the ‘fuel’) on a platinum surface (the ‘engine’) to water and oxygen,” Kraft continues. “During this reaction there is an uneven distribution of the molecules around the particle, which causes a movement of the liquid and thus drives the particle.”

The study has multiple implications. “With this project we showed that the special 3D printer can be used to build microswimmers of all shapes,” concludes Kraft. Usually research on microswimmers is done with spherical particles. But as the study shows, 3D printed microswimmers offer new opportunities. And such a funny little sailing boat that also breaks world records is of course great fun.