Marangoni effect visualized in two-dimensions Optical tweezers for gas bubbles.

摘要: In the report we demonstrate how, using laser light, effectively trap gas bubbles and transport them through a liquid phase to desired destination by shifting beam position. The physics underlying effect is complex but quite general as it comes from limited two-dimension, well-known, Marangoni effect. experimental microscope-based system consists of thin layer placed between two glass plates containing dye dissolved in solvent light that strongly absorbed dye. This point-like heat source locally changes surface tension nearby liquid-air interface. Because temperature gradients photo-triggered flows are induced leading self-amplification formation large-scale whirls. interface bending toward position allowing bubble upon suitable steering. Using various techniques (employing luminescent particles or crystals), visualize propelled tangential forces. helped us understand phenomenon analyze accompanying effects trapping. manipulation sessile droplets moving on via controlled with (i.e. "droplet catapult") demonstrated well.