Normal impact of adhesive microparticles with a film/substrate system: A numerical study

The rebound behavior of adhesive microparticles normally impacting a thin-film/substrate system is investigated by using a finite element method. The nonlinear interfacial adhesion property is implemented into the simulations by introducing piecewise-linear spring elements between the two impacting bodies. The effect of adhesion hysteresis is accounted for by assuming that the adhesion work during the incident stage is smaller than that during rebounding. The influences of the thickness and Young’s modulus of the thin film on the restitution coefficient, kinetic energy, force–displacement curves and critical capture velocity are also examined. It is found that a surface coated with a softer thin film can capture microparticles more easily. The softer the thin film, the lower the coefficient of restitution. With the increase in the incident velocity, the coefficient of restitution approaches unity. The present numerical model provides a convenient method to study the rebound behavior of adhesive microspheres with film/substrate systems and rough solid surfaces.