2018/07/31 by Theresa Jakuszeit, Ottavio A. Croze, Samuel Bell
Engineering · Materials Science · Mathematics · Physics and Astronomy · #Boundary value problem #Classical mechanics #Diffusion #Geology #Geometry #Lattice (music) #Mathematics #Mechanics #Micro and Nano Robotics #Microfluidic and Bio-sensing Technologies #Obstacle #Optics #Particle (ecology) #Physics #Pickering emulsions and particle stabilization #Quantum mechanics #Scattering #Specular reflection #Statistical physics #Surface (topology) #Thermal diffusivity #cond-mat.stat-mech #physics.bio-ph
paper · pdf · doi:10.1103/physreve.99.012610
published as Phys. Rev. E 99, 012610 (2019) · 5 pages + 4 supplemental pages, 3 figures + 5 supplemental figures
arxiv created 2018/10/23 · openalex publication_date 2019/01/22 · arxiv updated 2019/01/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Experiments have shown that self-propelled particles can slide along the surface of a circular obstacle without becoming trapped over long times. Using simulations and theory, we study the impact of boundary conditions on the diffusive transport of active particles in an obstacle lattice. We find that particle dynamics with sliding boundary conditions result in large diffusivities even at high obstacle density, unlike classical specular reflection. These dynamics are very well described by a model based on run-and-tumble particles with microscopically derived reorientation functions arising from obstacle-induced tumbles. This model, however, fails to describe fine structure in the diffusivity at high obstacle density predicted by simulations for pusherlike collisions. Using a simple deterministic model, we show that this structure results from particles being guided by the lattice. Our results thus show how nonclassical surface scattering introduces a dependence on the lattice geometry at high densities. We discuss implications for the study of bacteria in complex environments.