Thermal Cycling Apparatus and Method for Providing Thermal Uniformity

Abstract

An apparatus and method for rapid thermal cycling including a thermal diffusivity plate. The thermal diffusivity plate can provide substantial temperature uniformity throughout the thermal block assembly during thermal cycling by a thermoelectric module. An edge heater can provide substantial temperature uniformity throughout the thermal block assembly during thermal cycling.

1 . An apparatus for thermally cycling biological samples comprising:
 a thermal block assembly for receiving said biological samples;   a thermoelectric module coupled to said thermal block assembly; and   a heat sink, wherein said heat sink is coupled to said thermoelectric module with a thermal interface medium, wherein said heat sink comprises a base plate, fins, and a thermal diffusivity plate, and wherein said thermal diffusivity plate comprises a different material than said base plate and fins,   wherein said thermal diffusivity plate provides substantial temperature uniformity to said thermal block assembly during thermal cycling.   
   
   
       2 . The apparatus of  claim 1 , wherein said thermal diffusivity plate is positioned to couple to said thermoelectric module with the thermal interface medium. 
   
   
       3 . The apparatus of  claim 1 , wherein said thermal block assembly comprises at least one of silver, gold, aluminum, silicone carbide, and magnesium. 
   
   
       4 . The apparatus of  claim 1 , wherein said base plate and fins comprise aluminum. 
   
   
       5 . The apparatus of  claim 1 , wherein said thermoelectric module comprises a thermoelectric gap, wherein said thermoelectric gap provides substantial temperature uniformity throughout said thermal block assembly. 
   
   
       6 . The apparatus of  claim 5 , wherein said thermoelectric gap is less than 5 millimeters. 
   
   
       7 . The apparatus of  claim 1 , further comprising an edge heater, wherein said edge heater is coupled to the perimeter of said thermal block assembly. 
   
   
       8 . The apparatus of  claim 1 , wherein said apparatus provides a PCR cycle time of less than thirty seconds. 
   
   
       9 . An apparatus for thermally cycling biological samples comprising:
 a thermal block assembly for receiving said biological samples;   a thermoelectric module capable of heating and cooling, wherein the thermoelectric module is coupled to said thermal block assembly;   a heat sink; and   a thermal diffusivity plate comprising copper coupled to said thermoelectric module with a thermal interface medium and coupled to said heat sink, wherein said thermal diffusivity plate is positioned between said thermoelectric module and said heat sink and has a significantly greater thermal diffusivity than said heat sink, and provides substantial temperature uniformity to said thermal block assembly during thermal cycling.   
   
   
       10 . The apparatus of  claim 9 , wherein said substantial temperature uniformity provides cooling of at least 10° C. in at most ten seconds for said thermal block assembly. 
   
   
       11 . The apparatus of  claim 9 , wherein said thermal block assembly comprises silver and gold. 
   
   
       12 . The apparatus of  claim 9 , wherein said thermoelectric module comprises a thermoelectric gap, wherein said thermoelectric gap provides substantial temperature uniformity throughout said thermal block assembly. 
   
   
       13 . The apparatus of  claim 12 , wherein said thermoelectric gap is less than 5 millimeters. 
   
   
       14 . The apparatus of  claim 9 , further comprising an edge heater, wherein said edge heater is coupled to the perimeter of said thermal block assembly. 
   
   
       15 . The apparatus of  claim 1 , wherein said thermoelectric module comprises at least two power regions. 
   
   
       16 . The apparatus of  claim 1 , further comprising a seal positioned on top of said thermal block assembly. 
   
   
       17 . The apparatus of  claim 1 , wherein the thermal interface medium is thermal grease. 
   
   
       18 . An apparatus of  claim 1 , wherein said thermal diffusivity plate is positioned within said base plate. 
   
   
       19 . An apparatus of  claim 1 , wherein said thermoelectric module's horizontal surface area overlaps said thermal diffusivity plate's horizontal surface area. 
   
   
       20 . An apparatus of  claim 19 , wherein said thermoelectric module's horizontal surface area is larger than said thermal diffusivity plate's horizontal surface area. 
   
   
       21 . An apparatus of  claim 19 , wherein said thermal diffusivity plate's horizontal surface area is larger than said thermoelectric module's horizontal surface area. 
   
   
       22 . An apparatus of  claim 9 , wherein said thermal interface medium is thermal grease. 
   
   
       23 . An apparatus of  claim 9 , wherein said thermoelectric module's horizontal surface area overlaps said thermal diffusivity plate's horizontal surface area. 
   
   
       24 . An apparatus of  claim 23 , wherein said thermoelectric module's horizontal surface area is larger than said thermal diffusivity plate's horizontal surface area. 
   
   
       25 . An apparatus of  claim 23 , wherein said thermal diffusivity plate's horizontal surface area is larger than said thermoelectric module's horizontal surface area. 
   
   
       26 . An apparatus of  claim 9 , wherein said thermal diffusivity plate is positioned within a base plate of said heat sink.