MEMS-based integrated magnetic particle identification system

Abstract

The present invention provides a MEMS-based integrated particle identification system having a substrate, a magnetic structure, and a bioferrograph. The substrate includes a topside portion, backside portion and a flow system. The flow system includes a flow channel for accepting the flow of a stream of particles to identified. The magnetic structure is in physical communication with the topside and backside portions of the substrate and has at least two pole pieces. A plurality of pole piece embodiments are provided for generating a magnetic field that acts on magnetically susceptible particles in the flow stream. The bioferrograph has at least one sensor for identifying the presence and quantity of magnetically susceptible particles. A plurality of sensor embodiments are also provided.

1 - 13 . (canceled)  
     
     
         14 . A bioferrograph for identifying magnetically susceptible particles, the bioferrograph comprising: 
 (a) a silicon substrate having a topside and backside;    (b) the topside comprising a sensor portion for sensing the presence of at least one magnetically susceptible particle; and    (c) the backside comprising a magnetic portion having at least two pole pieces separated by a gap.    
     
     
         15 . The bioferrograph of  claim 14  wherein the sensor portion comprises at least one impedance-type sensor.  
     
     
         16 . The system of  claim 15  wherein the impedance-type sensor comprises at least two electrodes for sensing contact with a particle.  
     
     
         17 . The system of  claim 14  wherein the sensor portion comprises at least one resonant-type sensor.  
     
     
         18 . The system of  claim 17  wherein the resonant-sensor comprises at least one resonating material for sensing contact with a particle.  
     
     
         19 . The system of  claim 14  wherein the sensor portion comprises at least one magnetoresistive sensor.  
     
     
         20 . The system of  claim 19  wherein the magnetoresistive sensor comprises at least one sensing section having first and second electrodes and a magnetoresistive material therebetween.  
     
     
         21 - 33 . (canceled)  
     
     
         34 . A particle separation system having a bioferrograph, said bioferrograph comprising: 
 (a) a light source;    (b) a silicon substrate having a topside and backside;    (c) said topside comprising a sensor portion for sensing the presence of at least one immunofluorescently labeled particle;    (d) the backside comprising a magnetic portion having at least two pole pieces separated by a gap; and    wherein said light source emits light for exciting said at least one immunofluorescently labeled particle and said sensor portion detects the luminosity of said at least one immunofluorescently labeled particle.    
     
     
         35 . The system of  claim 34  wherein said light source comprises a light emitter and at least one optical fiber for directed light towards said sensor portion.  
     
     
         36 . The system of  claim 34  further comprises a computerized quantification system for correlating the detected luminosity with a quantity of particles.  
     
     
         37 . The system of  claim 34 , the particle separation system further comprising a magnetic structure comprising: 
 a first pole piece structure;    a second pole piece structure;    a first gap between the first and second pole piece structures; and    the first and second pole piece structures each comprising a plurality of discrete pole pieces and a plurality of secondary gaps disposed between the discrete pole pieces; and each discrete pole piece comprising an orthogonal geometry.    
     
     
         38 . The system of  claim 37  wherein the plurality of discrete pole pieces comprise at least a first and a second orthogonal geometry.  
     
     
         39 . The system of  claim 37  wherein the plurality of discrete pole pieces comprise a common length dimension.  
     
     
         40 . The system of  claim 37  wherein the plurality of discrete pole pieces comprises a common height dimension.  
     
     
         41 . The system of  claim 37  wherein the plurality of discrete pole pieces and the plurality of secondary gaps are configured to generate a substantially uniform magnetic field in the first gap.  
     
     
         42 . The system of  claim 37  wherein the plurality of discrete pole pieces and the plurality of secondary gaps are configured to approximate the magnetic field generated by a magnetic pole piece having a hyperbolic surface.  
     
     
         43 . The system of  claim 34 , the particle separation system further comprising a first pole piece structure having a substantially hyperbolic surface formed from plurality of perpendicular edges.  
     
     
         44 . The system of  claim 43 , further comprising: 
 a second pole piece structure having a substantially hyperbolic surface formed from plurality of perpendicular edges; and    a first gap between the first and second pole piece structures.