2017/03/31 by Nitzan Razin, Raphaël Voituriez, Raphael Voituriez +2
Engineering · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Biology #Biophysics #Classical mechanics #Computer science #Density gradient #Mechanics #Micro and Nano Robotics #Molecular Communication and Nanonetworks #Molecular motor #Motion (physics) #Object (grammar) #Physics #Position (finance) #Pressure gradient #Quantum mechanics #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.96.032606
published as Phys. Rev. E 96, 032606 (2017) · 16 pages, 9 figures
openalex publication_date 2017/09/15 · arxiv created 2017/09/30 · arxiv updated 2017/10/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We show how a gradient in the motility properties of noninteracting pointlike active particles can cause a pressure gradient that pushes a large inert object. We calculate the force on an object inside a system of active particles with position-dependent motion parameters, in one and two dimensions, and show that a modified Archimedes' principle is satisfied. We characterize the system, both in terms of the model parameters and in terms of experimentally measurable quantities: the spatial profiles of the density, velocity and pressure. This theoretical analysis is motivated by recent experiments, which showed that the nucleus of a mouse oocyte (immature egg cell) moves from the cortex to the center due to a gradient of activity of vesicles propelled by molecular motors; it more generally applies to artificial systems of controlled localized activity.