Heat-reduction methods and systems related to microfluidic devices

• US 8,734,733 B2
• Filed: 05/13/2013
• Issued: 05/27/2014
• Est. Priority Date: 02/14/2001
• Status: Active Grant

• Current Assignee: HandyLab Incorporated (Becton Dickinson & Co)
• Original Assignee: HandyLab Incorporated (Becton Dickinson & Co)
• Inventors: Handique, Kalyan
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Handy, Dwayne K
• Application Number:
  US13/892,559
• Publication Number:
  US 20130251602A1
• Time in Patent Office: 379 Days
• Field of Search: 422/68.1, 422/82.01, 422/502, 422/503, 422/504, 422/547, 422/551, 422/552, 436/147, 436/174, 436/180, 204/400, 204/424, 204/435, 204/436, 204/451
• US Class Current: 422/504
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/1822 using Peltier elements
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2300/1883 using thermal insulation
• CPC Class Codes: B01L 2300/1894 Cooling means; Cryo cooling
• CPC Class Codes: B01L 2400/0442 thermal energy, e.g. vaporisation, bubble jet
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 7/00 Heating or cooling apparatus autoclaves B01J3/04; Heat insulating devices
• CPC Class Codes: C12Q 1/6806 Preparing nucleic acids for analysis, e.g. for polymerase chain reaction [PCR] assay C12Q1/6804 takes precedence
• CPC Class Codes: H05B 3/22 non-flexible
• CPC Class Codes: H05K 3/10 in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

The present relates to a system and method for preventing or reducing unwanted heat in a microfluidic of the device while generating heat in selected regions of the device. Current can be supplied to a heating element through electric leads that are designed so that the current density in the leads is substantially lower than the current density in the heating element. Unwanted heat in the microfluidic complex can be reduced by thermally isolating the electric leads from the microfluidic complex by, for example, running each lead directly away from the microfluidic complex. Unwanted heat can be removed from selected regions of the microfluidic complex using one or more cooling devices.

Claims

1. An integrated microfluidic processing system comprising a microfluidic device, the device comprising:

a microfluidic complex comprising at least one thermally actuated component;

a thermally insulating substrate comprising a heating element configured to actuate the at least one thermally actuated component; and

at least one conductive lead for supplying electrical current from a current source to the heating element, wherein the lead has a lower current density than the heating element.

2. The system of claim 1, wherein the thermally actuated component comprises a valve.

3. The system of claim 1, wherein the thermally actuated component comprises a meltable material.

4. The system of claim 3, wherein the meltable material comprises wax or solder.

5. The system of claim 1, wherein the microfluidic complex comprises a plurality of flow channels, each flow channel comprising a reaction chamber.

6. The system of claim 5, wherein the heating element is further configured to heat at least one reaction chamber.

7. The system of claim 5, wherein the thermally insulating substrate further comprises a second heating element configured to heat at least one reaction chamber.

8. The system of claim 1, wherein the microfluidic device comprises a second substrate in thermal communication with the thermally insulating substrate, the microfluidic complex defined in part by the second substrate.

9. The system of claim 1, wherein the heating element and the at least one conductive lead each comprise a vertical thickness dimension in a direction orthogonal to a plane in which the thermally insulating substrate lies, wherein the vertical thickness dimension of the at least one conductive lead is greater than the vertical thickness dimension of the heating element.

10. The system of claim 1, wherein the heating element and the at least one conductive lead each comprise a horizontal thickness dimension in a direction parallel to a plane in which the thermally insulating substrate lies, wherein the horizontal thickness dimension of the at least one conductive lead is greater than the horizontal thickness dimension of the heating element.