“By moving the laser through the droplet in a controlled way, we can write the swimmer shape that we want,” said researcher Daniela Kraft. “Because the print is taking place inside the droplet, and we are printing layer by layer, we can maintain the open space [inside the tugboat cockpit].”
The team created the boat because it was “fun,” but also developed more research-specific shapes, including a spiral less than 5 microns in diameter. By tracking the motion, they were able to measure the speed and path of different types of particles.
The 3D printing technique opens the door to the creation of very specific shapes in order to emulate biological microswimmers or optimize their motion through fluids. “Ultimately, it will allow a greater control and design of the behavior of synthetic microswimmers, useful for applications in therapeutic diagnostics and drug delivery,” according to the research paper.