Patent ID: 8066494

Claim:
A micropump comprising: an elastic-member sheet having a diaphragm portion, an intake check valve portion, and a discharge check valve portion; a first case member attached to a first side of the elastic-member sheet, the first case member defining a vibration chamber; a second case member attached to a second side of the elastic-member sheet, the second case member defining a pump chamber, and the elastic-member sheet providing sealing between the first and second case members, the first and second case members defining an intake-side check valve at the intake check valve portion of the elastic-member sheet and a discharge-side check valve at the discharge check valve portion of the elastic-member sheet; and a piezoelectric actuator attached to the first side of the elastic-member sheet at the diaphragm portion and positioned within the vibration chamber; wherein a bending displacement of the piezoelectric actuator changes a volume of the pump chamber and alternately opens and closes the intake-side check valve and the discharge-side check valve to transport a fluid; the first case member includes a bottom plate member which is a flat plate, and a first intermediate member in which a vibration-chamber hole, an intake-passage hole isolated from the vibration-chamber hole, and a discharge-space hole isolated from the vibration-chamber hole are provided, the bottom plate member and the first intermediate member being stacked on each other; the second case member includes a top plate member which is a flat plate, and a second intermediate member in which a pump-chamber hole, an intake-space hole facing the intake-passage hole, and a discharge-passage hole facing the discharge-space hole are provided, the top plate member and the second intermediate member being stacked on each other; the intake check valve portion of the intake-side check valve is arranged to close the intake-passage hole, and the discharge check valve portion of the discharge-side check valve is arranged to close the discharge-passage hole; and each of the intake check valve portion and the discharge check valve portion includes a tongue shaped portion that is attached to the elastic-member sheet in a cantilever manner along one edge portion of the tongue shaped portion.