Self-Propulsion of a Metallic Superoleophobic Micro-Boat

TL;DR

This paper demonstrates a metallic micro-boat capable of self-propulsion driven by solutocapillary Marangoni flow, achieving velocities up to 0.05 m/s through alcohol-induced surface tension changes.

Contribution

It introduces a metallic superoleophobic micro-boat that self-propels using alcohol-induced surface tension gradients, supported by experimental and phenomenological modeling.

Findings

Maximal velocities of 0.05 m/s achieved.

Surface tension changes due to alcohol condensation drive motion.

A dynamic model describing the propulsion mechanism is provided.

Abstract

The self-propulsion of a heavy, superoleophobic, metallic micro-boat carrying a droplet of various aqueous alcohol solutions as a fuel tank is reported. The micro boat is driven by the solutocapillary Marangoni flow. The jump in the surface tension owing to the condensation of alcohols on the water surface was established experimentally. Maximal velocities of the self-propulsion were registered as high as 0.05 m/s. The maximal velocity of the center mass of the boat correlates with the maximal change in the surface tension, due to the condensation of alcohols. The mechanism of the self-locomotion is discussed. The phenomenological dynamic model describing the self-propulsion is reported.