SPREADING OF A MACROSCOPIC LATTICE-GAS

We present a simple mechanical model for dynamic wetting phenomena. Me tallic balls spread along a periodically corrugated surface simulating molecules of liquid advancing along a solid Substrate. A vertical sta ck of balls mimics a liquid droplet. Stochastic motion of the balls, d riven by mechanical vibration of the corrugated surface, induces diffu sional motion. Simple theoretical estimates are introduced and agree w ith the results of the analog experiments, with numerical simulation, and with experimental data for microscopic spreading dynamics.