2021/03/28 by Sumit Sinha, Abdul N. Malmi-Kakkada, Abdul N Malmi-Kakkada
Biochemistry, Genetics and Molecular Biology · Materials Science · Physics and Astronomy · #Adhesion #Adhesive #Advanced Thermodynamics and Statistical Mechanics #Chemical physics #Composite material #Geology #Material Dynamics and Properties #Materials science #Mechanics #Micro and Nano Robotics #Nanotechnology #Particle (ecology) #Physics #Surface finish #Surface roughness #cond-mat.soft #physics.bio-ph #q-bio.TO
paper · pdf · doi:10.1021/acs.jpcb.1c02758
published as The Journal of Physical Chemistry B (2021) · 20 pages, 3 figures
arxiv created 2021/03/28 · openalex publication_date 2021/09/09 · arxiv updated 2022/03/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Activity and self-generated motion are fundamental features observed in many living and non-living systems. Given that inter-particle adhesive forces are known to regulate particle dynamics, we investigate how adhesion strength controls the boundary growth and roughness in an active particle aggregate. Using particle based simulations incorporating both activity (birth, death and growth) and systematic physical interactions (elasticity and adhesion), we establish that inter-particle adhesion strength (fad) controls the surface roughness of a densely packed three-dimensional(3D) active particle aggregate expanding into a highly viscous medium. We discover that the surface roughness of a 3D active particle aggregate increases in proportion to the inter-particle adhesion strength, fad. We show that asymmetry in the radial and tangential active particle mean squared displacement (MSD) suppresses 3D surface roughness at lower adhesion strengths. By analyzing the statistical properties of particle displacements at the aggregate periphery, we determine that the 3D surface roughness is driven by the movement of active particle towards the core at high inter-particle adhesion strengths. Our results elucidate the physics controlling the expansion of adhesive 3D active particle collectives into a highly viscous medium, with implications into understanding stochastic interface growth in active matter systems characterized by self generated particle flux.