Researchers 3D-printed the smallest ship on Earth

The route to microswimmer research needs a microscopic guide.

Soft Matters

It looks like researchers at Leiden University really enjoy their work. As part of exploratory research on microswimmers, like bacteria, the team 3D-printed several shapes outside of the spherical norm. Along with spirals and helices, they also created a tiny Benchy tugboat. The ship is a common test for 3D printers, but the other tugboats aren’t 30 micrometers long — small enough to luge through a strand of human hair.

Finding a way to harness microswimmers could provide innovative ways to deliver medicine, a research field increasingly embracing microrobots. A particular avenue for this research favors battery-less drug delivery.

The microswimmers — The ship is a marvel in and of itself, complete with an intricate cockpit, but all of the researchers’ creations are impressive. Made with a Nanoscribe Photonic Professional printer, the tugboat and its sibling prints (including a wonky Starship Enterprise) are the product of intricate lasers honed on droplets. This allows for microswimmer particles with even tinier serrated tails and a flawless interior in the tugboat.

a) spiky sphere, b) spaceship, c) spiral, d) helix, e) trimer, and f) benchy tugboat.Soft Matter

“A laser is focused inside a droplet that locally hardens in the focal spot of the laser,” researcher Daniela Kraft told Gizmodo. “By moving the laser through the droplet in a controlled way, we can write the swimmer shape that we want. Because the print is taking place inside the droplet, and we are printing layer by layer, we can maintain the open space.”

The record-breaking, sailable tugboat doesn’t have a propeller; like everything researchers built, it moves forward as a result of platinum reacting with hydrogen peroxide. With 3D-printing, scientists are routinely able to expand knowledge around the microscopic world.