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Updated: Apr 5, 2026

A Microfluidic-based Hydrodynamic Trap for Single Particles
Published on: January 21, 2011
Trapping of interacting propelled colloidal particles in inhomogeneous media
Martin P Magiera1, Lothar Brendel1
1Faculty of Physics and CENIDE, University of Duisburg-Essen, D-47048 Duisburg, Germany.
Abstract:
A trapping mechanism for propelled colloidal particles based on an inhomogeneous drive is presented and studied by means of computer simulations. In experiments this method can be realized using photophoretic Janus particles driven by a light source, which is partially blocked by a shading mask. This leads to an accumulation of particles in the passive part. An equation for an accumulation parameter is derived using the effective inhomogeneous diffusion constant generated by the inhomogeneous drive. The impact of particle interaction on the trapping mechanism is studied, as well as the interplay between passivity-induced trapping and the emergent self-clustering of systems containing a high density of active particles. The combination of both effects makes the clusters more controllable for applications.
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