Microfluidic analytical apparatus

Abstract

A microfluidic analytical apparatus ( 10 ) comprising a microfluidic card pairing ( 12 ) with a corresponding circuit card ( 14 ) and the circuit card pairing ( 12 ) with corresponding conductive fingers ( 16 ). The microfluidic card ( 12 ) has a plurality of channels ( 32 ) and ports ( 54 ) on a top surface of the card in a desired configuration, the ports ( 54 ) in fluid communication with the channels ( 32 ). The circuit card ( 14 ) has a plurality of conductive pins ( 60 ) projecting from a bottom surface of the card and having a configuration that corresponds to the particular configuration of the ports ( 54 ) of the microfluidic card ( 12 ) that is paired with. The circuit card ( 14 ) is received within a holder ( 20 ) that provides that provides multiple functions. Conductive pads ( 18 ) are disposed on a top surface of the circuit card ( 14 ), the pads ( 18 ) in electrical communication with the conductive pins ( 60 ) and corresponding to a configuration of conductive fingers ( 16 ) connected to a power source to provide voltage to the microfluidic card ( 12 ) for analytical operations. Additionally, detection difficulties associates with non-uniformities present on the card surface are overcome using a detection system incorporating a compliantly mounted microscopic head.

1 . An interchangeable circuit card for providing electrical contact with one or more ports in a microfluidic chip, said card comprising: 
 first and second opposed major surfaces; one or more conductive pads disposed on said first surface;    one or more conductive pins projecting from said second surface, said one or more pins in electrical communication with said conductive pads whereby an electrical connection can be provided between a power source through said one or more pins to said one or more ports to effect an electrokinetic process.    
     
     
         2 . The apparatus of  claim 1  wherein said electrokinetic process includes separation by capillary electrophoresis.  
     
     
         3 . The apparatus of  claim 1  further comprising groups of pads on said first surface of said circuit card.  
     
     
         4 . The apparatus of  claim 3  further comprising traces wherein said traces connect groups of pins to one of said conductor pads and said traces terminate in said pads.  
     
     
         5 . The apparatus of  claim 3  further comprising conductive fingers in electrical communication with a power source and making electrical contact with said pads.  
     
     
         6 . The apparatus of  claim 5  wherein said conductive fingers align with a group of said pads.  
     
     
         7 . The apparatus of  claim 6  wherein the number of pads in said grouping is equal to the number of conductive fingers.  
     
     
         8 . The apparatus of  claim 1  further comprising a circuit cardholder having said circuit card disposed within it.  
     
     
         9 . The apparatus of  claim 8  wherein said circuit card holder having said circuit card disposed within it, rests against surfaces of said microfluidic card and covers said ports of said microfluidic card, decreasing evaporation of material within said ports.  
     
     
         10 . The apparatus of  claim 8  wherein said holder includes a stop and said stop prevents said conductive pin from contacting a port surface when received by said port.  
     
     
         11 . The apparatus of  claim 9  wherein said pins are suspended within said ports.  
     
     
         12 . The apparatus of  claim 8  wherein said apparatus further comprises an upper frame upon which said circuit card holder rests and a lower frame upon which said microfluidic card rests.  
     
     
         13 . The apparatus of  claim 12  wherein said holder has four sides and has wings extending from two sides, wherein said wings are insertable within said upper frame.  
     
     
         14 . The apparatus of  claim 8  further comprising a securing device wherein said securing device secures said microfluidic card into contact relation with said circuit card holder and said conductive pins are removably received by said ports.  
     
     
         15 . The apparatus of  claim 1  further comprising an optical head disposed in a holder adjacent to the second major surface of the card and in sliding contact relation with the second major surface of said card.  
     
     
         16 . The apparatus of  claim 1  further comprising a compliantly mounted optical head wherein said head is compliantly disposed within a holder and is adjacent to the second major surface of the card and in sliding contact relation with the second major surface.  
     
     
         17 . The apparatus of  claim 16  wherein said microfluidic card includes a non-uniform surface and said compliantly mounted optical head is in a sliding contact relation with said non-uniform surface.  
     
     
         18 . A microfluidic analytical apparatus comprising: 
 a microfluidic card having, 
 (a) first and second opposed major surfaces,  
 (b) a plurality of microchannels formed between the major surfaces, each microchannel having ports extending to the first major surface of the microfluidic card, thereby forming an array of ports,  
   a circuit card in moveable proximity to the microfluidic card having, 
 (i) first and second opposed major surfaces,  
 (ii) an array of conductive pins projecting from said second surface and disposed adjacent to and projecting toward the first major surface of the card in a removably receivable relation with selected ports thereof, said array of pins corresponding to a select array of ports and said pins being arranged in groups,  
 (iii) conductive pads disposed on said first surface of said circuit card, a pad corresponding to and electronically connected to a group of pins, and  
   conductive fingers in electrical communication with a power source and making electrical contact with said pads, said fingers aligning with said pads.    
     
     
         19 . The apparatus of  claim 18  further comprising: 
 an optical head disposed in a holder adjacent to the second major surface of the card in sliding contact relation with the second major surface of said card.  
 
     
     
         20 . The apparatus of  claim 18  further comprising a circuit cardholder.  
     
     
         21 . The apparatus of  claim 20  wherein said holder includes a stop and said stop prevents said conductive pin from contacting a port surface when received by said port.  
     
     
         22 . The apparatus of  claim 18  wherein said microscope is beneath said microfluidic card and said fingers are above said microfluidic card.  
     
     
         23 . A microfluidic analytical apparatus comprising: a microfluidic card having first and second opposed major surfaces, a plurality of microchannels formed between the major surfaces, each microchannel having ports extending to the first major surface of the microfluidic card, thereby forming an array of ports; 
 an optical head compliantly disposed in a holder, said head adjacent to the second major surface of the microfluidic card and in sliding contact relation with the second opposed major surface of said card.    
     
     
         24 . The apparatus of  claim 23  wherein said optical head includes a nose protruding from said head and said nose is in a sliding contact relation with the second major surface of said card.  
     
     
         25 . The apparatus of  claim 23  further comprising ball bearings wherein said bearings rigidly mount said head in a lateral direction within said holder.  
     
     
         26 . The apparatus of  claim 24  further comprising an air cylinder providing vertical movement to said head.  
     
     
         27 . A microfluidic analytical apparatus comprising: a microfluidic card having first and second opposed major surfaces, a plurality of microchannels formed between the major surfaces, each microchannel having ports extending to the first major surface of the microfluidic card, thereby forming an array of ports; 
 a circuit. card in moveable proximity to the microfluidic card having first and second opposed major surfaces, an array of conductive pins projecting from said second surface and disposed adjacent to and projecting toward the first major surface of the card in a removably receivable relation with selected ports thereof; and    a circuit cardholder, wherein said circuit card is disposed within said holder and said holder rests against said microfluidic card when said card receives said conductive pin, thereby forming a seal between said circuit card and said microfluidic card.    
     
     
         28 . The apparatus of  claim 27  wherein said circuit cardholder includes a stop and said stop suspends said conductive pins within said ports.  
     
     
         29 . An optical head for collecting optical signals from a microfluidic card, the optical head comprising: 
 a lens mounted in a holder capable of lateral movement with respect to a surface of a microfluidics card, the holder providing a compliant mounting with respect to the surface of the microfluidic card such that the lens undergoes vertical movement responsive to deformities in the surface of the microfluidics card, the vertical movement maintaining the lens at a constant vertical distance from the surface of the microfluidic card.    
     
     
         30 . The optical head of  claim 29  wherein said compliant mounting comprises a cylindrical spacer coaxially disposed between said lens and said surface of said microfluidic card, and forcing means for holding the cylindrical spacer in contact with said surface.