摘要 |
A droplet generation device comprising a reservoir split into at least two regions by a substantially liquid impermeable barrier, a perforate membrane connecting one of said regions, containing, in use, the liquid to be dispensed, to the atmosphere, such that vibration of the membrane causes the liquid to be ejected through the perforate membrane into the atmosphere, and a pressure control system consisting of one or more valves in which at least one valve vents gas into the reservoir in response to a pressure difference, ΔPin, across it that is less than zero, and at least one valve is connected to a non-liquid-containing region of the reservoir and vents gas out of the reservoir in response to a pressure difference, ΔPout, across it that is greater than ΔPin, where ΔPin and ΔPout are the absolute pressure of the gas in the reservoir minus the absolute atmospheric pressure outside of the reservoir. |