US Patent 10302075 Fluid pumping systems, devices and methods

A reciprocating positive displacement pump comprises a flexible diaphragm fluidically separating a pumping chamber from an actuation chamber. The membrane may include bumps or other features on the side of the membrane facing the pumping chamber that space at least a portion of the membrane away from the rigid chamber wall when the membrane is in a minimum-pumping-chamber volume position. Such structures may prevent pockets of fluid from being caught away from the inlet and outlet by keeping portions of the membrane spaced away from the rigid pumping chamber wall even when the pumping chamber volume is at a minimum.