Levich Institute Seminar Announcement, 03/25/2014
Tuesday, 03/25/2014
2:00 PM
Steinman Hall, Room #312
(Chemical Engineering Conference Room)

Dr. Hassan Masoud
The Courant Institute (NYU) and
Princeton University

"Individual and Collective Surfing of Chemically Active Particles "


We study theoretically the motion of particles located at a liquid-gas interface. These particles release a chemical species that locally changes the surface tension. The consequent gradients in surface tension and the associated Marangoni flow then move the particles along the interface. We call this surfing. First, we consider the surfing of a single spheroidal particle at a semi-infinite interface and derive closed-form expressions for the self-induced surfing speed. Our derivations are based on the Lorentz reciprocal theorem which eliminates the need for developing the detailed flow field. Next, we probe the collective surfing of particles located at the interface of a finite-depth liquid layer. We calculate the linear stability condition of this system and examine the consequences of instability on the flow in the bulk. We also show that for sufficiently deep and shallow fluid layers this system yields the two-dimensional Keller-Segel model for the collective chemotaxis of slime mold colonies.


Hassan Masoud is an ICAM post-doctoral fellow working jointly with Michael Shelley at the Courant Institute of Mathematical Sciences and Howard Stone in the Mechanical and Aerospace Engineering Department at Princeton University. Hassan received his B.S. degree in Aerospace Engineering from the Sharif University of Technology, Tehran, Iran in 2006. Subsequently, he joined the State University of New York at Buffalo where he earned his M.S. degree in Mechanical Engineering in 2009. Hassan then moved to the Georgia Institute of Technology and obtained his Ph.D., also in Mechanical Engineering, in 2012. He employs theory and computer simulations to solve problems at the boundaries of engineering, physics, and biology. Hassanís research interests include mechanics of soft and active materials, fluid-structure interactions, small scale fluid mechanics, and biomimetic design.


Mechanics of soft and active materials, Fluid-structure interactions, Small scale fluid mechanics, Biomimetic design

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