Viscous droplets impacting a superhydrophobic cantilever beam

The dynamics of viscous droplets impacting a superhydrophobic cantilever beam reveal a rebound mechanism governed by the interplay between droplet viscosity and substrate elasticity. This study experimentally investigates the impact behavior of water–glycerol droplets on a superhydrophobic cantilever beam. The effects of droplet mass concentration, beam stiffness, and Weber number on coalescence, spreading, receding, and rebounding behaviors are systematically examined. Spreading and initial receding dynamics remain largely unaffected by droplet viscosity and beam stiffness, as these stages are primarily dominated by inertial forces. In contrast, late-stage receding rates decrease with increasing mass concentration and decreasing beam stiffness, indicating a growing influence of viscous forces. Based on these observations, a dimensionless scaling model for contact time during viscous droplets impact on superhydrophobic cantilever beams is proposed. The contact time is predominantly determined by beam stiffness in such elastic systems. At low mass concentrations, the effect of concentration on contact time is negligible; at higher concentrations, a slight increase in contact time is observed, though the fundamental dependence on stiffness remains unchanged. This work provides quantitative insights and practical design guidelines for anti-icing surfaces and other applications involving complex fluid–structure interactions under dynamic droplet impact.