Self-Propelling Rotator Driven by Soluto-Capillary Marangoni Flows

TL;DR

This paper reports a polymer tubing rotator driven by solutocapillary Marangoni flows from camphor dissolution, demonstrating long-lasting rotation, supported by a phenomenological model and experimental scaling laws.

Contribution

It introduces a new self-propelling rotator driven by solutocapillary flows, with a validated phenomenological model and experimentally tested scaling laws.

Findings

Rotation lasts for dozens of hours.

Surface tension change due to camphor dissolution is about 0.3 mN/m.

Model and scaling laws accurately describe the self-propulsion.

Abstract

The self-propelled, longstanding rotation of the polymer tubing containing camphor continuing for dozens of hours is reported. The rotator is driven by the solutocapillary Marangoni flows owing to the dissolution of camphor. The phenomenological model of self-propulsion is suggested and verified. Scaling laws describing the quasi-stationary self-propulsion are proposed and tested experimentally. The change in the surface tension, arising from the dissolution of camphor and driving the rotator is estimated as 0.3 mN/m.