Visualization of Motion Inside Droplets

Abstract

Droplets are encountered in several natural systems, i.e. dew formation, cloud formation and practical applications such as inkjet printer, condenser, Protein Crystalprotein crystallization systems, digital microfluidic systems, disease diagnosis, droplet lenses, nano-patterning and droplet-based manufacturing systems. The internal hydrodynamics of droplets influence the behaviour and performance of these applications. Visualization of internal dynamics inside droplets is challenging due to the small-scale and curvature effect. The present study reports the ongoing work carried out at IITK on the interesting fluid flow dynamics inside droplets. Some of the case studies related to evaporating droplets, like a single evaporating droplet, two evaporating droplets, dryingDrying pattern and protein crystallization, have been reported. Marangoni stresses and buoyancy-driven Rayleigh convection are primarily responsible for motion inside droplets. The internal hydrodynamics inside a droplet shows several complexities irrespective of its simple symmetrical geometry.