Propulsion at Low Reynolds numbers
Unit operation in droplet-based microfludics
Much attention has been drawn recently to various droplet-based microfluidic techniques as an alternative technology for “lab-on-a-chip” systems based upon micromanipulation of discrete droplets. Despite enormous experimental progress, the theoretical description of basic microfluidic operations in such systems is still quite limited, majorly, due to the complex nature of the confined flows and the effect of the boundaries. We investigate some basic “unit operations” of droplet-based microfluidics, such as droplet generation, motion and controlled breakup in confined geometries.
Artificial nanomotors and low Reynolds-number locomotion Modern technology is about the control of tiny objects. The benefits of tiny artificial swimmers for medicine, for example, could be enormous. A tiny robot may swim through the arteries, digestive system, spinal canal, etc., transmit images and deliver microscopic payloads to parts of the body, or perform minimally invasive microsurgeries outside the reach of existing technologies. Our research currently focuses on various aspects of locomotion of artificial (magnetic) micro- and nano-swimmers and study of optimal propulsion gaits of biological microswimmers. Selected topics in viscous flows Understanding of hydrodynamics at microscopic scale is great importance in modern research and technology. We study various processes, such as dynamics and stability of thin liquid films, thermo- and soluto-capillary (Marangoni) flows, droplet spreading on surfaces, hydrodynamic interaction and diffusion of particles in a viscous dispersion, bacterial deposition on surfaces and other topics.
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K. I. Morozov and A. M. Leshansky, “Chiral Magnetic Nanomotors”, Nanoscale 6, 1580 (2014)
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T. Qiu, T.-C. Lee, A. G. Mark, K. I. Morozov, A. M. Leshansky, and P. Fischer, “Swimming by Reciprocal Motion at Low Reynolds Number”, Nature Comm. 5, 1 (2014)
E. Margalit, A. M. Leshansky, V. Freger, “Modeling and analysis of hydrodynamic and physico-chemical effects in bacterial deposition on surfaces”, Biofouling, 29, 977 (2013).
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O. Assad, A. M. Leshansky, T. Stelzner, S. Christiansen and H. Haick, “A Spray-Coating Route for Highly Aligned and Large-Scale Arrays of Silicon Nanowires”, ACS Nano, 6, 4702 (2012)
A. M. Leshansky, “Enhanced low-Reynolds-number propulsion in heterogeneous viscous environments”, Phys. Rev. E, 80, 051911 (2009)
A. M. Leshansky and L. M. Pismen, “Breakup of drops in a microfluidic T-junction”, Phys. Fluids, 21, 023303 (2009)
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D. J. Pine, J.P. Gollub, J.F. Brady and A.M. Leshansky, “Chaos and threshold for irreversibility in sheared suspensions”, Nature 438, 997 (2005)