2019/05/22 by Cèlia Lozano, Lozano, Celia, Benno Liebchen +7
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Micro and Nano Robotics #Orbital Angular Momentum in Optics #Pattern Formation and Solitons (nlin.PS) #Pickering emulsions and particle stabilization #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.1905.08980
openalex publication_date 2019/05/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Combining experiments and computer simulations, we use a spatially periodic and flashing light-field to direct the motion of phototactic active colloids. Here, the colloids self-organize into a density spike pattern, which resembles a shock wave and propagates over long distances, almost without dispersing. The underlying mechanism involves a synchronization of the colloids with the light-field, so that particles see the same intensity gradient each time the light-pattern is switched on, but no gradient in between (for example). This creates a pulsating transport whose strength and direction can be controlled via the flashing protocol and the self-propulsion speed of the colloids. Our results might be useful for drug delivery applications and can be used to segregate active colloids by their speed.