A method for depositing a coating comprising a polymer and impermeable dispersedsolid on a substrate, comprising the following steps: discharging at least oneimpermeable dispersed solid in dry powder form through a first orifice； dischargingat least one polymer in dry powder form through a second orifice； depositing thepolymer and/or impermeable dispersed solid particles onto said substrate,wherein an electrical potential is maintained between the substrate and theimpermeable dispersed solid and/or polymer particles, thereby forming saidcoating； and sintering said coating under conditions that do not disrupt theactivity and/or function of the substrate. A similar method is provided for depositinga coating comprising a hydrophobic polymer and a water-vapor-trapping materialon a substrate.
