Assembly and manipulation of mesoscopic particles using micro bubbles in thermo-optical tweezers

Micro bubbles can be used to generate and manipulate flows in the ambient fluid in optical tweezers. Here, we develop a novel technique of generating micro bubbles in a controlled manner in thermo-optical tweezers, where the temperature variation of the surface tension at the liquid-gas interface generates tangential thermo-capillary stress. This produces flows in the surrounding fluid, which can be controlled using the bubble. An analytical solution of the thermocapillary problem, based on the Stokes and heat equations, yields the flow profile around the bubble, which is realized experimentally in single and two-bubble systems.