Crystallization and flow in active patch systemsElectronic supplementary information (ESI) available. See DOI: 10.1039/c6sm01898j

• Main Authors: Hasnain, Jaffar, Menzl, Georg, Jungblut, Swetlana, Dellago, Christoph
• Format: Journal Article
• Language: English
• Published: 01.02.2017
• ISSN: 1744-683X; 1744-6848
• DOI: 10.1039/c6sm01898j

Based upon recent experiments in which Janus particles are made into active swimmers by illuminating them with laser light, we explore the effect of applying a light pattern on the sample, thereby creating activity inducing zones or active patches. We simulate a system of interacting Brownian diffusers that become active swimmers when moving inside an active patch and analyze the structure and dynamics of the ensuing stationary state. We find that, in some respects, the effect of spatially inhomogeneous activity is qualitatively similar to a temperature gradient. For asymmetric patches, however, this analogy breaks down because the ensuing stationary state is specific to partial active motion. Boundary conditions and configurations of the colloidal particles that become active swimmers if they inhabit the red region of the simulation cell and perform Brownian diffusion if they enter the blue region. This dynamical heterogeneity leads to crystallization and mass transport.