Smallest boat

The smallest boat ever sailed is a 11.5-micrometer-long (0.0004-inch) reproduction of "Benchy the Tugboat", a ship's model used to test 3D printers. This tiny ship was made by a team at Leiden University's Huygens-Kamerlingh Onnes Laboratory led by Dr Daniela Kraft and Dr Rachel Doherty. Benchy made her maiden voyage on 30 October 2020.

Benchy the Tugboat was made using a process called two-photon polymerisation as part of study examining the properties of anisotropic (i.e. irregularly shaped) colloidal microswimmers (tiny particles that propel themselves through water). The ships were created as part of a construction technology test during an academic research project, but not tested in water until after the research had been published. Before being placed in the water, the body was plated with a patch of platinum which, with the addition of a tiny amount of hydrogen peroxide, makes Benchy self-propelling.

Kraft's research is focussed on how shape affects the motion and interactions of biological microswimmers, such as bacteria and algae. Synthetic microswimmers such as Benchy are a great model system for that, because they are much simpler than their biological cousins. In addition, they provide answers to interesting questions in non-equilibrium systems (they are inherently out-of-equilibrium because they consume energy to propel). Kraft hopes to learn about the design principles for creating efficient swimmers, which could be used one day for drug delivery applications. The study was published in the journal Soft Matter on 12 October 2020.