Devices and methods for using centripetal acceleration to drive fluid movement in a microfluidics system

Abstract

This invention relates to methods and apparatus for performing microanalytic and microsynthetic analyses and procedures. The invention provides a microsystem platform and a micromanipulation device for manipulating the platform that utilizes the centripetal force resulting from rotation of the platform to motivate fluid movement through microchannels. The microsystem, platforms of the invention are also optionally provided having system informatics and data acquisition, analysis and storage and retrieval informatics encoded on the surface of the disk opposite to the surface containing the fluidic components. Methods specific for the apparatus of the invention for performing any of a wide variety of microanalytical or microsynthetic processes are provided.

1 . A method for performing assays using a microsystem platform, wherein the microsystem platform comprises: 
 a multiplicity of sample inlet ports arranged around the center of the microsystem platform for receiving a biological sample, wherein each of the sample inlet ports is operatively linked to;    a multiplicity of microchannels arrayed radially away from the center of the microsystem platform, said microchannels being operatively linked to;    a multiplicity of reagent reservoirs containing a reagent specific for an analyte to be measured, wherein release of the reagent from each of the reservoirs is controlled by a microvalve, and wherein the multiplicity of microchannels is also operatively linked to;    a multiplicity of analyte detection chambers arranged peripherally around the outer edge of the microsystem platform,    wherein movement of the biological sample from the inlet port and through the microchannel and movement of the reagent from the reagent reservoir and through the microchannel is motivated by centripetal force generated by rotational motion of the microsystem platform,    the method comprising:    operating each of the microvalves to control release of the reagent from the reagent reservoirs by generating a signal, at a time and for a duration whereby the reagent moves into the microchannel and is mixed with the biological sample;    detecting an amount of analyte present in the biological sample; and    storing data representing the amount of analyte present in the biological sample upon the microsystem platform.    
     
     
         2 . The method of  claim 1 , wherein operating each of the microvalves to control release of the reagent from the reagent reservoirs by generating a signal comprises: 
 setting an RPM for a first valve actuation; and    upon reaching the RPM, spinning the microsystem platform at the RPM.    
     
     
         3 . The method of  claim 2 , further comprising setting an RPM for a second valve actuation.  
     
     
         4 . The method of  claim 1 , further comprising outputting a representation of the amount of analyte present in the biological sample.  
     
     
         5 . The method of  claim 4 , wherein outputting the representation comprises sending the representation to a display.  
     
     
         6 . The method of  claim 1 , further comprising identifying a status of the microvalve operation.  
     
     
         7 . The method of  claim 6 , further comprising if the status is unacceptable, terminating the method.  
     
     
         8 . The method of  claim 1 , further comprising sending the data representing the amount of analyte present in the biological sample to a storage device via communication selected from the group consisting of telephone, facsimile transmission, and wireless communication.  
     
     
         9 . The method of  claim 1 , wherein operating each of the microvalves to control release of the reagent from the reagent reservoirs by generating a signal comprises calculating the time required to transfer the reagent through the microchannel to mix with the biological sample.  
     
     
         10 . The method of  claim 9 , wherein calculating the time required to transfer the reagent through the microchannel to mix with the biological sample comprises calculating D t  by:  
           D   t   =V/Q , if  L ≦(4 V/πD   2 ), and    D   t =( V/Q )*(4π D   2   L/ 4 V ), if  L >(4 V/πD   2 )  
       wherein D t  is the time required to transfer a volume V from a reservoir through a microchannel of length L, Q is a rate of flow, and D is a diameter of the microchannel.  
     
     
         11 . A computer readable medium having stored therein instructions for causing a processing unit to execute the method of  claim 1 .  
     
     
         12 . A system comprising: 
 a microsystem platform including: 
 a multiplicity of sample inlet ports arranged around the center of the microsystem platform for receiving a biological sample, wherein each of the sample inlet ports is operatively linked to;  
 a multiplicity of microchannels arrayed radially away from the center of the microsystem platform, said microchannels being operatively linked to;  
 a multiplicity of reagent reservoirs containing a reagent specific for an analyte to be measured, wherein release of the reagent from each of the reservoirs is controlled by a microvalve, wherein movement of the biological sample from the inlet port and through the microchannel and movement of the reagent from the reagent reservoir and through the microchannel is motivated by centripetal force generated by rotational motion of the microsystem platform,  
   a processing unit; and    machine language instructions stored in data storage executable by the processing unit to perform functions including:    operating each of the microvalves to control release of the reagent from the reagent reservoirs by generating a signal, at a time and for a duration whereby the reagent moves into the microchannel and is mixed with the biological sample;    detecting an amount of analyte present in the biological sample; and    storing data representing the amount of analyte present in the biological sample upon the microsystem platform.    
     
     
         13 . The system of  claim 12 , wherein the machine language instructions are executable to further perform functions including: 
 generating the time by calculating        D   t   =V/Q , if  L ≦(4 V/πD   2 ), and    Dt =( V/Q )*(4π D   2   L/ 4 V ), if  L >(4 V/TD   2 )    wherein D t  is the time required to transfer a volume V from a reservoir through a microchannel of length L, Q is a rate of flow, and D is a diameter of the microchannel.