Systems, methods, and devices are disclosed for producing substantially uniform droplets. The system includes a fluid reservoir vessel defining a fluid reservoir, a separation membrane at one end of the fluid reservoir, at least one capillary channel at an opposite end of the fluid reservoir, a solution dispenser, and a piezo actuator in contact with a separation membrane. The separation membrane has a thickness greater than about 0.2 mm, and the solution dispenser maintains the fluid reservoir filled with fluid such that the fluid simultaneously contacts the separation membrane and the capillary channel. The solution dispenser maintains the fluid reservoir under pressure to create a fluid stream exiting the capillary. The piezo actuator is in contact with the separation membrane on a side opposite that in contact with the fluid, and the piezo actuator transfers a pressure wave through the fluid in the fluid reservoir to break up the fluid stream into uniform droplets.