Spontaneous autophoretic motion of isotropic particles

Sebastien Michelin (1) , Eric Lauga (2, 2) , Denis Bartolo (3)

1 LadHyX - Laboratoire d'hydrodynamique
2 MAE - UC San Diego - Department of Mechanical and Aerospace Engineering [Univ California San Diego]
3 Laboratoire de Physique

Suspended colloidal particles interacting chemically with a solute can self-propel by autophoretic motion when they are asymmetrically patterned (Janus colloids). Here we demonstrate theoretically that such anisotropy is not necessary for locomotion and that the nonlinear interplay between surface osmotic flows and solute advection can produce spontaneous and self-sustained motion of isotropic particles. Solving the classical autophoretic framework for isotropic particles, we show that, for given material properties, there exists a critical particle size (or Peclet number) above which spontaneous symmetry-breaking and autophoretic motion occur. A hierarchy of instabilities is further identified for quantized critical Peclet numbers. (C) 2013 AIP Publishing LLC.

Domains: Physics [physics]; Mechanics [physics]; Fluid mechanics [physics.class-ph]; Engineering Sciences [physics]; Mechanics [physics.med-ph]; Fluids mechanics [physics.class-ph]

Sebastien Michelin, Eric Lauga, Denis Bartolo. Spontaneous autophoretic motion of isotropic particles. Physics of Fluids, 2013, 25 (6), pp.061701. ⟨10.1063/1.4810749⟩. ⟨hal-00996484⟩