Micro-dosing pumps and valves

Abstract

A fluid mircro pump or valve of a two-stage pulsatile peristaltic type. The pump body has an inlet port and an outlet port. First and second layers of SiO are formed on an Si wafers disposed in face-to-face relationship within the body. The first layers define flexible diaphragms bulge, responsive to a first fluid pressure, between a flat shape and a dome shape containing a pumping chamber. The domes overlap laterally so that fluid is pumped from on chamber to the other as the diaphragms are bulged in serial fashion. Control chambers apply fluid pressure to bulge the domes.

1 . A device for micro-dose pumping or valving of a fluid, the device comprising a pump body having an inlet port and an outlet port, first and second layers disposed in face-to-face relationship within the body, the first layer being formed with a first diaphragm having an outer side, the diaphragm being sufficiently flexible to bulge, responsive to a first fluid pressure on a first outer side, between a flat shape and a first dome shape which projects away from the second layer and forms a first pumping chamber therewith, the second layer being formed with a second diaphragm having a second outer side, the second diaphragm being sufficiently flexible to bulge, responsive to a second fluid pressure on the second outer side, between a flat shape and a second dome shape which projects away from the first layer forms a second pumping chamber therewith, the first diaphragm being offset laterally with respect to the second diaphragm sufficient so that the first and second domes partially overlap to enable fluid transfer between the domes, and a flow channel in the body for communicating fluid from the inlet port to the first and second pumping chambers and the outlet port.  
     
     
         2 . A device as in  claim 1  which further comprises control means for producing the first and second fluid pressure.  
     
     
         3 . A device as in  claim 2  in which the control means comprises a first control chamber for containing the first pressure and a second control chamber for containing the second pressure, the first and second control chambers being in fluid communication with respective first and second outer sides.  
     
     
         4 . A device as in  claim 1  having a plurality of the pump bodies, the first and second layers with the diaphragm in an array.  
     
     
         5 . A method for fabricating a micro-dose pump or valve comprising the steps of forming first and second flexible diaphragms of SiO on surfaces of respective first and second Si wafers, placing the surfaces in face-to-face relationship along a plane with the diaphragms in lateral overlapping relationship, enabling the first and second diaphragms to bulge from flat shapes toward respective first and second dome shapes in directions away from the plane with the domes enclosing respective first and second volumes and with the volumes being in fluid communication when the diaphragms are both bulged into the domes, causing a sample of fluid to enter the first volume when the first diaphragm is in the first dome shape, causing the sample to enter the second volume when the diaphragms are both bulged into the domes, and directing the sample to egress from the second volume when the second the diaphragm is in its flat shape.  
     
     
         9 . A device made by the method of claim  8 .