Pumping effect of heterogeneous meniscus formed around spherical particle.

The particle-induced acceleration of the film front depends both on the shape of the meniscus that forms around the particle foot and the liquid "reservoir" in the film that can be pumped thanks to the presence of the particle. The study validates the presence of three stages of pressure difference between the upstream and downstream regions of the meniscus around the particle, which leads to the local acceleration/deceleration of the macroscopic contact line. We indicate that asymmetric meniscus around the particle foot produces a net pressure force driving liquid and accelerating the liquid-film front.