(419g) Bouncing Particles on a Stratified Coating

We combine lubrication theory and solid linear elasticity to model the elastohydrodynamic deformation of a rigid, spherical particle impacting a stratified surface – a soft coating atop a rigid substrate. The model depends on three dimensionless parameters, the Stokes number, elasticity, and coating thickness, which collectively determine whether the particle will stick to or rebound against the stratified surface. We show that thickness moderates the degree to which elasticity affects the rebound criteria, and vice versa. We also demonstrate the possibility of approximating a stratified surface as an elastic half-space with an elasticity between the rigid substrate and soft coating. This ‘effective elasticity’ of the half-space couples both the elasticity and thickness of the stratified surface condition while maintaining the same rebound criteria.