Measuring Lateral Capillary Forces on Floating Particles using the Moses Effect

TL;DR

This paper introduces a new technique to measure lateral capillary forces on floating particles by using magnetic fields to induce surface curvature, analyzing equilibrium positions through classical mechanics and force balance equations.

Contribution

It presents a novel, user-friendly method combining magnetic manipulation and force analysis to detect capillary forces on floating particles, supported by theoretical modeling.

Findings

Successful measurement of lateral capillary forces using the proposed method

Agreement between experimental equilibrium positions and theoretical predictions

Demonstration of the technique's effectiveness for analyzing particle interactions

Abstract

This study presents a novel and user-friendly technique for detecting the lateral capillary force on a floating spherical particle. The technique leverages the interplay between the capillary attracting forces, hydrostatic pressure forces, and magnetic repulsion forces. A magnetic field is applied to induce a surface curvature in the liquid, resulting in a non-uniform distribution of capillary and hydrostatic pressure forces across the particle's surface. This leads to a stable equilibrium position of the particle at a specific distance from the magnet. The study analyzes the equilibrium position and other relevant parameters in comparison with the developed theory. Classical mechanics and intermolecular forces are applied to establish the theoretical basis for the method, modeling the behavior of the particle in response to the magnetic field, surface curvature, and hydrostatic pressure. The equilibrium position of the particle is determined by numerically solving the balance of forces equation.