Capillary Dipoles: Towards Thermocapillary Micromanipulation of Multiple Particles Floating at the Free Surface

Abstract

We present a contribution to thermocapillary micromanipulation of floating particles at the free surfaces. Based on a physical model for the so-called capillary dipole interaction, the force between two floating particles is predicted with a Bessel function, whose magnitude can be calculated from the measured distance between particles. This force is then considered as a disturbance force and rejected in the control scheme thanks to a feedforward strategy. Theoretical results for this strategy as well as an experimental proof of concept are given.