Streaming electric field, electroviscous effect, and electrokinetic liquid flows in the induced pressure‐driven transport of active liquids in narrow capillaries

Abstract

In this paper, we develop a theory for studying the electrokinetic effects in a charged nanocapillary filled with active liquid. The active particles present within the active liquid are self‐driven, demonstrate vortex defects, and enforce a circumferentially arranged polarization field. Under such circumstances, there is the development of an induced pressure‐gradient‐driven transport dictated (similar to diffusioosmotic transport) by the presence of an axial gradient in the activity (or the concentration of the active particles). This pressure‐driven transport has a profile different from the standard Hagen–Poiseuille flow in a nanocapillary. Also, this induced pressure‐driven flow drives electrokinetic effects, which are characterized by the generation of a streaming electric field, associated electroosmotic (EOS) transport opposing pressure‐driven flow, and electroviscous effect. We quantify these effects as functions of dimensionless parameters that vary inversely as the strength of the activity‐induced pressure‐driven flow and salt concentrations. Overall, we anticipate that this paper will draw immense attention toward a new type of activity‐induced pressure‐driven flow and associated electrokinetic phenomena in charged nanoconfinements.