Shaping high-speed Marangoni flow in liquid films by microscale perturbations in surface temperature

The authors show that a variety of controlled flow patterns, including toroidal cells and surface doublets, can be generated in 80 - 400 μ m thick liquid films by placing scanning microscopy probes with integrated heaters just above the surface ( < 400 μ m separation). The probes project sharp te...

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Bibliographic Details
Published in:Applied physics letters 2007-01, Vol.90 (3), p.034102-034102-3
Main Authors: Basu, Amar S., Gianchandani, Yogesh B.
Format: Article
Language:English
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Summary:The authors show that a variety of controlled flow patterns, including toroidal cells and surface doublets, can be generated in 80 - 400 μ m thick liquid films by placing scanning microscopy probes with integrated heaters just above the surface ( < 400 μ m separation). The probes project sharp temperature gradients on the liquid surface which drive Marangoni flow. Flow velocities approaching 3000 μ m ∕ s are experimentally demonstrated on length scales of 20 - 200 μ m with < 20 mW input power. For liquids such as water and oil, in which the surface tension coefficient is ≈ 0.2 mN ∕ m K , flows > 1000 μ m ∕ s can be accomplished with surface temperature perturbations < 1 ° C . This technique enables microfluidic manipulation on unpatterned substrates.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.2430777