We studied the release and transfer of polystyrene (PS) microdots on mica. The PS dots were released from the mica in water. The release was affected by the density of K+ ions on the mica surface, which was controlled by pretreatment with K2CO3 solutions. The release of PS dots became dominant at the concentrations above [K+](crit) = 1 x 10(-4) M in the K2CO3 solution. In this concentration region, repulsive forces appeared as a result of the hydration of K+ ions on the mica (J. Colloid Interface Sci. 1981, 83, 53 1). This result suggests that the repulsive hydration force causes the release of the PS dots. Followed by the release process, we successfully demonstrated the transfer of the array of PS dots from the mica to another substrate.