Guiding catalytically active particles with chemically patterned surfaces

Abstract

Catalytically active Janus particles suspended in solution create gradients in the chemical composition of the solution along their surfaces, as well as along any nearby container walls. The former leads to self-phoresis, while the latter gives rise to chemi-osmosis, providing an additional contribution to self-motility. Chemi-osmosis strongly depends on the molecular interactions between the diffusing chemical species and the wall. We show analytically, using an approximate "point-particle" approach, that by chemically patterning a planar substrate one can direct the motion of Janus particles: the induced chemi-osmotic flows can cause particles to either "dock" at the chemical step between the two materials, or to follow a chemical stripe. These theoretical predictions are confirmed by full numerical calculations. Generically, docking occurs for particles which tend to move away from their catalytic caps, while stripe-following occurs in the opposite case. Our analysis reveals the physical mechanisms governing this behavior.

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Cited by in corpus (29)

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• Hydrodynamic Mobility Reversal of Squirmers near Flat and Curved Surfaces
• Theory of light-activated catalytic Janus particles
• Diffusion-based height analysis reveals robust microswimmer-wall separation
• Effective interactions between inclusions in an active bath
• Self-diffusiophoresis induced by fluid interfaces
• Self-Propelled Colloidal Particle Near a Planar Wall: A Brownian Dynamics Study
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• Polarization-Density Patterns of Active Particles in Motility Gradients
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• Self-propulsion in 2D Confinement: Phoretic and Hydrodynamic Interactions
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• Phase coexistence in a monolayer of active particles induced by Marangoni flows
• Mechanochemical Active Ratchet
• Electrokinetic Janus micromotors moving on topographically flat chemical patterns
• Effective squirmer models for self-phoretic chemically active spherical colloids
• Photocatalytic magnetic microgyroscopes with activity-tunable precessional dynamics
• Autophoresis of a Janus particle near a planar wall: a lubrication limit
• Thermotaxis of Janus Particles