Electromagnetically bonded pumps and pump subassemblies and methods of fabrication

Abstract

Example embodiments of piezoelectric pumps and subassemblies for pumps (including diaphragm pumps, both piezoelectric and non-piezoelectric) are formed with structure and/or materials suitable for electromagnetic bonding, and are formed by electromagnetic bonding processes, such as laser welding, for example. In a first example embodiment of electromagnetic bonding pump fabrication technology, a pump ( 20 ) is comprised of a base member ( 22 ) and a diaphragm layer ( 24 ). The diaphragm layer ( 24 ) covers at least a portion of the base member and defines a pumping chamber ( 26 ) between the base member ( 22 ) and the diaphragm layer ( 24 ). The diaphragm layer ( 24 ) comprises a piezoelectric central region ( 30 ) selectively deformable upon application of an electrical signal for pumping fluid into and out of the pumping chamber ( 26 ). An electromagnetically transmissive region ( 32 ) essentially surrounds the central piezoelectric region ( 30 ). An electromagnetic weld ( 34 ) bonds the electromagnetically transmissive region ( 30 ) of the diaphragm layer to the base member ( 22 ). In a second example embodiment, a pump ( 20 ′) comprises a pump base member ( 22 ) having a pump chamber surface ( 44 ) and a valve interface surface ( 46 ). An inlet port ( 36 ) and an outlet port ( 38 ) are provided in the pump base member. A piezoelectric diaphragm layer ( 24 ) is electromagnetically welded to the pump chamber surface ( 44 ) for defining a pumping chamber ( 26 ) between the pump base member and the diaphragm layer. A valve subassembly ( 50 ) is electromagnetically welded to the valve interface surface ( 46 ) for providing an inlet valve ( 52 ) which selectively opens and closes the inlet port ( 36 ) and an outlet valve ( 54 ) which selectively opens and closes the outlet port ( 38 ).

1 . A pump comprising: 
 a base member having at least one port;    a diaphragm layer covering at least a portion of a surface of the base member and defining a pumping chamber between the base member and the diaphragm layer, the diaphragm layer being bonded by a first bond to the base member;    a valve subassembly positioned on the base member for selectively communicating fluid through the port, the valve subassembly being bonded by a second bond to the base member;    wherein at least one of the first bond and the second bond is an electromagnetic weld.    
   
   
       2 . The apparatus of  claim 1 , wherein the diaphragm layer coveres at least a portion of a first surface of the base member and the valve subassembly is positioned on a second surface of the base member, the second surface being opposite the first surface.  
   
   
       3 . The apparatus of  claim 1 , wherein both the first bond and the second bond are electromagnetic welds.  
   
   
       4 . The apparatus of  claim 1 , wherein the bond is one of a laser bond, an infrared bond, and an ultrasonic bond.  
   
   
       5 . The apparatus of  claim 1 , wherein the base member has a region which is transmissive of electromagnetic energy of the electromagnetic weld and an electromagnetic absorptive zone in which at least one of the first bond and the second bond is formed.  
   
   
       6 . A method of making a pump comprising: 
 forming a first bond to mount a diaphragm layer to a base member whereby the diaphragm layer covers at least a portion of a surface of the base member and defines a pumping chamber between the base member and the diaphragm layer;    forming a second bond to mount a valve subassembly to the base member, the valve subassembly being situated for selectively communicating fluid through a port formed in the base member;    using electromagnetic bonding to form one of the first bond and the second bond.    
   
   
       7 . The method of  claim 6 , further comprising: 
 forming the first bond to mount the diaphragm layer to the base member whereby the diaphragm layer covers at least a portion of a first surface of the base member; and    forming the second bond to mount a valve subassembly to a second surface of the base member, the second surface being opposite to the first surface.    
   
   
       8 . The method of  claim 6 , further comprising using electromagnetic bonding to form both the first bond and the second bond.  
   
   
       9 . The method of  claim 8 , further comprising essentially simultaneously forming the first bond and the second bond.  
   
   
       10 . The method of  claim 1 , wherein the electromagnetic bonding is one of laser welding, infrared welding, and ultrasonic welding.  
   
   
       11 . The method of  claim 1 , wherein the base member has a region which is transmissive of electromagnetic energy of the electromagnetic weld and an electromagnetic absorptive zone, and further comprising: 
 directing an electromagnetic beam in a path in the electromagnetic absorptive zone to form one of the first bond and the second bond.    
   
   
       12 . A pump comprising: 
 a base member;    a diaphragm layer covering at least a portion of the base member and defining a pumping chamber between the base member and the diaphragm layer, the diaphragm layer comprising: 
 a piezoelectric central region selectively deformable upon application of an electrical signal for pumping fluid into and out of the pumping chamber;  
 an electromagnetically transmissive region essentially surrounding the central piezoelectric region;  
 an electromagnetic weld for bonding the electromagnetically transmissive region of the diaphragm layer to the base member.  
   
   
   
       13 . The apparatus of  claim 12 , wherein the base member is an essentially planar plate having an inlet port and an outlet port.  
   
   
       14 . The apparatus of  claim 12 , wherein the electromagnetically transmissive region is comprised of a thermal polymer, a thermoplastic elastomer, a thermoplast, or a combination thereof.  
   
   
       15 . The apparatus of  claim 12 , wherein the base member has a region which is transmissive of electromagnetic energy of the electromagnetic weld and an electromagnetic absorptive zone in which the electromagnetic weld is formed.  
   
   
       16 . A method of fabricating a pump comprising: 
 positioning a diaphragm layer upon a pump base member, the diaphragm layer comprising a central piezoelectric region and an electromagnetically transmissive region which essentially surrounds the diaphragm region; and    applying electromagnetic energy to the electromagnetically transmissive region to weld the diaphragm layer to the pump base plate, thereby defining a pump chamber between the diaphragm layer and the pump base plate.    
   
   
       17 . The method of  claim 16 , wherein the step of applying the electromagnetic energy comprises directing an electromagnetic beam on an essentially closed path through the electromagnetically transmissive region of the diaphragm layer and around the central piezoelectric region of the diaphragm layer to form the pump chamber.  
   
   
       18 . The method of  claim 16 , wherein the electromagnetic beam is one of a laser beam, an infrared beam, and an ultrasonic beam.  
   
   
       19 . The method of  claim 16 , wherein the base member has a region which is transmissive of electromagnetic energy of the electromagnetic weld and an electromagnetic absorptive zone, and further comprising: 
 directing an electromagnetic beam in a path in the electromagnetic absorptive zone to form a bond.    
   
   
       20 . A valve subassembly for a pump comprising: 
 a pump interface layer having an interface layer flap;    a subassembly cover layer having a cover layer flap;    an intermediate layer positioned between the interface layer and the cover layer, the intermediate layer having an intermediate layer flap;    at least one of the interface layer and the cover layer being formed from a electromagnetically transmissive material;    an electromagnetic weld for bonding the flap of the interface layer to the flap of the cover layer to form a valve flap, the valve flap comprising the flap of the intermediate layer sandwiched between the flap of the interface layer and the flap of the cover layer.    
   
   
       21 . The apparatus of  claim 20 , wherein the interface layer is the electromagnetically transmissive.  
   
   
       22 . The apparatus of  claim 20 , wherein the electromagnetically transmissive material is a thermal polymer, a thermoplastic elastomer, a thermoplast, or a combination thereof.  
   
   
       23 . A method of fabricating a valve subassembly for a pump comprising: 
 forming flaps in each of an interface layer, an intermediate layer, and a cover layer;    positioning the intermediate layer between the interface layer and the cover layer;    electromagnetically bonding the flap of the interface layer to the flap of the cover layer whereby a valve flap is formed, the valve flap being comprised of the flap of the intermediate layer sandwiched between the flap of the interface layer and the flap of the cover layer.    
   
   
       24 . The method of  claim 23 , further comprising: 
 forming at least one of the interface layer and the cover layer from an electromagnetically transmissive material;    electromagnetically welding the flap of the interface layer to the flap of the cover layer.    
   
   
       25 . The method of  claim 24 , further comprising forming the interface layer from the electromagnetically transmissive material.  
   
   
       26 . The method of  claim 24 , wherein the electromagnetically transmissive material is a thermal polymer, a thermoplastic elastomer, a thermoplast, or a combination thereof.  
   
   
       27 . The method of  claim 23 , further comprising welding the flap of the interface layer to the flap of the cover layer by traversing an electromagnetic beam around a pattern which outlines a shape of the valve flap.  
   
   
       28 . The method of  claim 27 , wherein the electromagnetic beam is one of a laser beam, an infrared beam, and an ultrasonic beam.  
   
   
       29 . The method of  claim 27 , wherein the pattern is formed in the interface layer.  
   
   
       30 . A pump subassembly comprising: 
 a pump base member, the pump base member having a port formed therein;    a valve for selectively opening and closing the port, the valve comprising:    a pump interface layer having an interface layer flap;    a subassembly cover layer having a cover layer flap;    an intermediate layer positioned between the interface layer and the cover layer, the intermediate layer having an intermediate layer flap;    at least one of the interface layer and the cover layer being formed of an electromagnetically transmissive material;    an electromagnetic flap weld for bonding the flap of the interface layer to the flap of the cover layer whereby the flap of the intermediate layer sandwiched between the flap of the interface layer and the flap of the cover layer forms a valve flap aligned with the port, the valve flap being deflectable for selectively opening and closing the port;    an electromagnetic cover weld for welding the cover layer to the interface layer; and    a valve subassembly weld for welding the interface layer to the base member.    
   
   
       31 . The apparatus of  claim 30 , wherein the interface layer is electromagnetically transmissive.  
   
   
       32 . The apparatus of  claim 30 , wherein the electromagnetically transmissive material is a thermal polymer, a thermo-plastic elastomer, a thermoplast, or a combination thereof.  
   
   
       33 . The apparatus of  claim 30 , wherein the electromagnetic cover weld extends substantially around a periphery of the cover layer.  
   
   
       34 . A method of fabricating a valve subassembly for a pump comprising: 
 (1) forming flaps in each of an interface layer, an intermediate layer, and a cover layer;    (2) positioning the intermediate layer between the interface layer and the cover layer thereby forming a multilayer sandwich;    (3) positioning the multilayer sandwich on a pump base member;    (4) bonding the flap of the interface layer to the flap of the cover layer whereby a valve flap is formed, the valve flap being comprised of the flap of the intermediate layer sandwiched between the flap of the interface layer and the flap of the cover layer;    (5) bonding the cover layer to the interface layer; and    (6) bonding the interface layer to the pump base member.    
   
   
       35 . The method of  claim 34 , further comprising performing steps (4)-(6) after both step (2) and step (3) have been performed.  
   
   
       36 . The method of  claim 34 , further comprising performing steps (4)-(6) essentially simultaneously.  
   
   
       37 . The method of  claim 34 , further comprising performing steps (4) before step (3).  
   
   
       38 . The method of  claim 34 , further comprising: 
 forming at least one of the interface layer and the cover layer from an electromagnetically transmissive material;    electromagnetically welding the flap of the interface layer to the flap of the cover layer.    
   
   
       39 . The method of  claim 38 , further comprising forming the interface layer from the electromagnetically transmissive material.  
   
   
       40 . The method of  claim 38 , wherein the electromagnetically transmissive material is a thermal polymer, a thermoplastic elastomer, a thermoplast, or a combination thereof.  
   
   
       41 . The method of  claim 34 , further comprising welding the flap of the interface layer to the flap of the cover layer by traversing an electromagnetic beam around a pattern which outlines a shape of the valve flap.  
   
   
       42 . The method of  claim 41 , wherein the electromagnetic beam is one of a laser beam, an infrared beam, and an ultrasonic beam.  
   
   
       43 . The method of  claim 41 , wherein the pattern is formed in the interface layer.  
   
   
       44 . A pump comprising: 
 a pump base member having a pump chamber surface and a valve interface surface;    an inlet port and an outlet port provided in the pump base member;    a piezoelectric diaphragm layer which is electromagnetically welded to the pump chamber surface for defining a pumping chamber between the pump base member and the diaphragm layer;    a valve subassembly which is electromagnetically welded to the valve interface surface of the pump base member for providing an inlet valve which selectively opens and closes the inlet port and an outlet valve which selectively opens and closes the outlet port.    
   
   
       45 . The pump of  claim 44 , wherein the piezoelectric diaphragm layer comprises: 
 a piezoelectric central region selectively deformable upon application of an electrical signal for pumping fluid into and out of the pumping chamber;    an electromagnetically transmissive region essentially surrounding the central piezoelectric region;    an electromagnetic weld for bonding the electromagnetically transmissive region of the diaphragm layer to the pump chamber surface of the pump base member.    
   
   
       46 . The apparatus of  claim 45 , wherein the electromagnetically transmissive region is comprised of a thermal polymer, a thermoplastic elastomer, a thermoplast, or a combination thereof.  
   
   
       47 . The pump of  claim 44 , wherein the valve subassembly comprises: 
 a pump interface layer having an interface layer inlet flap and an interface layer outlet flap;    a subassembly cover layer having a cover layer inlet flap and a cover layer outlet flap;    an intermediate layer positioned between the interface layer and the cover layer, the intermediate layer having an intermediate layer inlet flap and an intermediate layer outlet flap;    at least one of the interface layer and the cover layer being formed from a electromagnetically transmissive material;    an electromagnetic inlet valve weld for bonding the inlet flap of the interface layer to the inlet flap of the cover layer for forming the inlet valve, the inlet valve comprising the inlet flap of the intermediate layer sandwiched between the inlet flap of the interface layer and the inlet flap of the cover layer;    an electromagnetic outlet valve weld for bonding the outlet flap of the interface layer to the outlet flap of the cover layer for forming the outlet valve, the outlet valve comprising the outlet flap of the intermediate layer sandwiched between the outlet flap of the interface layer and the outlet flap of the cover layer.    
   
   
       48 . The apparatus of  claim 47 , wherein the interface layer is the electromagnetically transmissive.  
   
   
       49 . The apparatus of  claim 47 , wherein the electromagnetically transmissive material is a thermal polymer, a thermoplastic elastomer, a thermoplast, or a combination thereof.  
   
   
       50 . The apparatus of  claim 47 , wherein the inlet valve is centrally formed with respect to the interface layer, the intermediate layer, and the cover layer.