ME 100/200 Seminar on "Viscosity of suspension of swimming bacteria"


Monday, April 26, 2010 - 4:00pm to 5:00pm


ESB 1001


Igor Aronson, Northwestern University & Argonne National Laboratories

Abstract:  Measurements of the shear viscosity in suspensions of swimming Bacillus subtilis in free standing liquid films have revealed that the viscosity can decrease by up to a factor of seven compared to the viscosity of the same liquid without bacteria or with non-motile bacteria. The reduction in viscosity is observed in two complimentary experiments: one studying the decay of a large vortex induced by a moving probe and another measuring the viscous torque on a rotating magnetic particle immersed in the film. The viscosity depends on the concentration and swimming speed of the bacteria. The viscosity reduction is attributed to the effect of self-propulsion of swimming bacteria.

Host: Sumita Pennathur

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