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Oscillatory coalescence of droplets in an alternating electric field
Phys. Rev. Fluids 2, 063603 – Published 8 June, 2017
DOI: https://doi.org/10.1103/PhysRevFluids.2.063603
Abstract
Partial coalescence of microdroplets is of interest for a number of microfluidic applications where a controlled fluid transfer from one droplet to another is required for mixing, dispensing, and metering of chemical and biological fluids. We report a phenomenon of oscillatory coalescence of water droplets situated in an alternating electric field. The oscillatory coalescence exists in a range of electric capillary numbers and fluid conductivities and proceeds through a finite number of cycles. Each cycle includes attractive and repulsion stages and results in a partial fluid transfer through a liquid bridge formed between droplets during the repulsion stage. We propose an energy model to describe the phenomenon and define its limit of existence.
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