Cross-stream migration of active particles

Katuri, Jaideep; Uspal, William E.; Simmchen, Juliane; Miguel-López, Albert; Sánchez, Samuel

doi:10.1126/sciadv.aao1755

Cited by 84 publications

(99 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These particles are obtained by depositing a thin film of catalyst material over a spherical core of a material without catalytic properties. 7 Typical realizations, which will be of main interest for the present study, are Pt on polystyrene (Pt/PS) particles [8][9][10][11][12][13] and Pt on silica (Pt/SiO 2 ) particles; [14][15][16][17][18] another example, which is recently attracting much interest, is that of titania on silica (TiO 2 /SiO 2 ) particles, 19,20 for which the decomposition of H 2 O 2 occurs via photocatalysis upon illumination with UV light of a suitable wavelength. The reviews in Refs.…”

Section: Introductionmentioning

confidence: 99%

Floor- or Ceiling-Sliding for Chemically Active, Gyrotactic, Sedimenting Janus Particles

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Floor- or Ceiling-Sliding for Chemically Active, Gyrotactic, Sedimenting Janus Particles

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…In analogy with biological systems, this directed spatial migra- * Electronic address: uspal@hawaii.edu tion can be considered a form of "taxis". Recent studies have investigated the rheotactic response of chemically active particles to hydrodynamic flow, [17][18][19][20] gravitactic response to the earth's gravitational field, [4,21,22] "viscotactic" response to viscosity gradients, [23] chemotactic response to gradients in the concentration of chemical "fuel", [24][25][26][27][28][29][30][31][32] and "thigmotactic" response to gradients in the material composition of bounding surfaces [33][34][35]. These various forms of taxis can be understood on the basis of the microscopic physics of how the ambient field couples to the activity and motion of the particle.…”

Section: Introductionmentioning

confidence: 99%

Theory of light-activated catalytic Janus particles

Uspal

2019

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

We study the dynamics of active Janus particles that self-propel in solution by light-activated catalytic decomposition of chemical "fuel." We develop an analytical model of a photo-active selfphoretic particle that accounts for "self-shadowing" of the light by the opaque catalytic face of the particle. We find that self-shadowing can drive "phototaxis" (rotation of the catalytic cap towards the light source) or "anti-phototaxis," depending on the properties of the particle. Incorporating the effect of thermal noise, we show that the distribution of particle orientations is captured by a Boltzmann distribution with a nonequilibrium effective potential. Furthermore, the mean vertical velocity of phototactic (anti-phototactic) particles exhibits a superlinear (sublinear) dependence on intensity. Overall, our findings show that photo-active particles exhibit a rich "tactic"' response to light, which could be harnessed to program complex three-dimensional trajectories. arXiv:1811.05108v2 [cond-mat.soft]

show abstract

“…This stability leads to the decrease of the effective rotational diffusion of the active particles in this region as well as the emergence of rheotaxis away from walls. Our findings can be experimentally verified using biological or artificial swimmers in a converging flow [76] and should be extended to study the influence of hydrodynamic interactions. .…”

Section: Resultsmentioning

confidence: 56%

Focusing of active particles in a converging flow

et al. 2017

View full text Add to dashboard Cite

We consider active particles swimming in a convergent fluid flow in a trapezoid nozzle with no-slip walls. We use mathematical modeling to analyze trajectories of these particles inside the nozzle. By extensive Monte Carlo simulations, we show that trajectories are strongly affected by the background fluid flow and geometry of the nozzle leading to wall accumulation and upstream motion (rheotaxis). In particular, we describe the non-trivial focusing of active rods depending on physical and geometrical parameters. It is also established that the convergent component of the background flow leads to stability of both downstream and upstream swimming at the centerline. The stability of downstream swimming enhances focusing, and the stability of upstream swimming enables rheotaxis in the bulk.

show abstract

Cross-stream migration of active particles

Abstract: Active spheres swimming in a flow near a surface spontaneously adopt an orientation that allows them to swim across streamlines.

Cited by 84 publications

References 59 publications

Floor- or Ceiling-Sliding for Chemically Active, Gyrotactic, Sedimenting Janus Particles

Floor- or Ceiling-Sliding for Chemically Active, Gyrotactic, Sedimenting Janus Particles

Theory of light-activated catalytic Janus particles

Focusing of active particles in a converging flow

Contact Info

Product

Resources

About