Oscillatory Reversible Osmotic Growth of Sessile Saline Droplets on a Floating Polydimethylsiloxane Membrane

We report a cyclic growth/retraction phenomena observed for saline droplets placed on cured poly (dimethylsiloxane) (PDMS) membrane with thickness of 7.8 ± 0.1 µm floating pure water surface. Osmotic mass transport across the micro-scaled PDMS provided growth sessile followed by evaporation droplets. NaCl crystals were in vicinity triple line at stage. The cycle was reversible. A model osmotic transfer is suggested and verified. first stage well-approximated universal linear relationship, whose slope independent initial radius droplet. physical qualitatively explains time evolution droplet size. reported process demonstrates potential use industrial desalination.