Patent attributes
A liquid dispenser includes first and second liquid chambers. The second liquid chamber is in fluid communication with liquid supply and liquid return channels. A flexible membrane separates and fluidically seals the first and second liquid chambers from each other. The flexible membrane, residing in a first position, includes a residual compressive stress that exceeds an onset buckling stress of the flexible membrane. A heater, associated with the second liquid chamber, is selectively actuated to create a pressure pulse in a liquid that causes the flexible membrane to move from the first position to a second position to eject liquid through a nozzle of the first liquid chamber. In one embodiment, a liquid supply provides liquid that flows continuously from the liquid supply through the liquid supply channel through the second liquid chamber through the liquid return channel and back to the liquid supply during a drop dispensing operation.
