Related Experiment Video
Updated: Feb 11, 2026

On the Preparation and Testing of Fuel Cell Catalysts Using the Thin Film Rotating Disk Electrode Method
Published on: March 16, 2018
Rotation of a floating hydrophobic disk: influence of line tension
Janine Emile1, Hervé Tabuteau, Olivier Emile
1UMR CNRS 6251 IPR, Université Rennes 1, 35042 Rennes, France.
Abstract:
The rotation of a sub-millimeter size disk over a water bath is reported. The origin of the rotation arises from the transfer of angular momentum from a plane wave diffracted by an asymmetrical picture printed on the disk. Because of its hydrophobic character, the viscous friction contribution to the rotational motion of the object floating on the air/liquid interface is weak. From the driving optical torque and the steady-state rotation, we measure the contribution of the line tension in the femto-Newton range.
Related Concept Videos
Surface Tension, Capillary Action, and Viscosity
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
Tension
Faraday Disk Dynamo
Electric Field of a Charged Disk
The system's symmetry is in the cylindrical directions across the plane of the charge. As a result, the electric fields created by various surface charge elements nullify each other in the direction parallel to the surface. Thereby, the resulting electric field is perpendicular to the plane. Since the disk is...
Surface Tension of Fluid
Surface tension varies...
Buoyancy and Stability for Submerged and Floating Bodies

