Patent ID: 8746130

Claim:
A diaphragm pump, comprising: a pump chamber comprising an inlet opening and an outlet opening; a passive silicon check valve at the inlet opening; a passive silicon check valve at the outlet opening; a metallic pump diaphragm that adjoins the pump chamber; and an actuator for moving the pump diaphragm from a first end position, which defines a first pump chamber volume, to a second end position, which defines a second pump chamber volume, a difference between the first pump chamber volume and the second pump chamber volume defining a stroke volume, wherein the pump chamber comprises a pump chamber floor, which is opposite the metallic pump diaphragm, said pump chamber floor being adapted to the maximum deflection of the pump diaphragm, a gap remaining between the pump chamber floor and the pump diaphragm when the pump diaphragm is in the second end position, which defines a smaller pump chamber volume than the first end position, which gap offers, for a flow through the gap, a flow resistance no larger than a flow resistance of the passive check valve at the outlet opening or than a flow resistance of the passive check vale at the inlet opening, wherein the check valves comprise a valve flap and a support ridge on which the valve flap rests when the check valve is closed, said support ridge comprising a width of ≦50 μm, ≦10 μm, or ≦5 μm, and wherein the gap that remains between the pump chamber floor and the pump diaphragm when the pump diaphragm is in the second end position that defines a smaller pump chamber volume than the first end position is larger in a central area of the pump chamber than in an edge area of the pump chamber.