Particle Deposition Dynamics in Evaporating Droplets: Patterned Wettability Substrate Simulation

Patterned substrate wettability is considered as a strategy for controlling particle deposition in evaporating droplets. In contrast to magnetic-field-based particle manipulation, the focus is placed on modifying internal droplet flow by controlling contact-line motion. A pseudopotential LBM framework coupled with heat transfer and nanoparticle transport is used to simulate evaporation on substrates with radially patterned receding contact angles. Repeated pinning and depinning of the contact line alters capillary and Marangoni flows, leading to changes in particle distribution. The analysis demonstrates how wettability patterning can suppress coffee-ring formation and improve deposition uniformity.