Heat pump equipment and components

Abstract

A heat pump comprises one or more thermoelectric devices and a heat sink having a raised portion with a top surface for thermally coupling with a planar surface of the one or more thermoelectric devices. The raised portion of the heat sink comprises an outer periphery and a raised central area surrounded by a void area to provide more uniform thermal conductivity when clamped into an assembly. The raised central area is elliptical, circular, or rounded in shape, corresponding to the shape of the uneven thermal conductivity caused by the clamping pressure applied to the heat sink. The void area can be substantially continuous and completely surround the central raised area. The void can include discrete supports formed of a material with lower thermal conductivity. The supports can be elastic, such as an O-ring, and are disposed in a recess defined in the void area.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 792,345, filed January 14, 2019, which is hereby incorporated by reference in its entirety for all purposes. Technical Field

[0003] The present invention relates to a heat pump and radiator assembly, in particular a heat pump and radiator for thermal circulation of chemical or biological samples. Background Art

[0004] Heat pumps are widely used for thermal cycling of sample blocks, which are metal blocks that hold reaction vessels used in chemical and biochemical testing, particularly multi-tube or multi-container plates. Such sample blocks typically contain a planar array of recesses or wells, each containing a separate sample container. The test procedures typically performed on samples in sample blocks often require maintaining precise temperature control and heating and cooling the samples in discrete, programmed steps.

[0005] The polymerase chain reaction (PCR) is one of many examples of a chemical process performed on multiple samples that requires precise temperature control, with rapid temperature changes between different stages of the process. PCR amplifies DNA, meaning it produces multiple copies of a DNA sequence from a single copy. PCR is typically performed in various reaction vessels, such as microtiter plates, test tubes, or capillaries, in an instrument that provides reagent transfer, temperature control, and optical detection. Each stage of the process is temperature-sensitive, with different stages performed at different temperatures for designated periods of time, and this sequence is repeated cyclically. In a typical process, the sample is first heated to approximately 95°C to "melt" (separate) the double strands, then cooled to approximately 55°C to anneal (hybridize) the primers to the separated strands, and then heated again to approximately 72°C to extend the primers using a polymerase. This sequence is repeated to double the product DNA, and each cycle can take anywhere from a fraction of a minute to two minutes, depending on the equipment, reaction scale, and degree of automation. Another example of a chemical process involving temperature changes and a high degree of control is nucleic acid sequencing. Other examples will be apparent to those knowledgeable in the fields of general molecular biology and biochemistry.

[0006] The above process is often performed on a large number of samples using automated laboratory equipment, each of which has a relatively small volume, typically on the microliter scale. The core component of the equipment is the reaction module, which includes a sample block, a thermoelectric device or array of such devices that contacts the bottom side of the sample block, and a heat sink associated with the thermoelectric device, all of which have appropriate thermal interfaces and are tightly clamped together within the assembly to achieve maximum heat conduction. In some embodiments, adjacent components are directly bonded to each other. In other embodiments, a thermal interface material, such as synthetic graphite (e.g., Tgon), can be used between adjacent components to improve heat distribution.

[0007] While improved heat sinks have been proposed that utilize grooves or discrete voids, particularly along or near the edges of the heat sink plate, to reduce edge losses, anomalous and non-uniform temperature distributions within the sample block still exist. Therefore, there is a need for further improved heat pump and heat sink assemblies that provide more consistent, uniform temperature distribution and thermal conductivity to provide improved temperature control when thermally cycling a sample block. Summary of the Invention

[0008] Conventional technology heat pump arrays and heat sinks are typically included in an integral assembly, wherein a thermally conductive plate of the heat sink is clamped to the heat pump to ensure consistent thermal contact between a raised top surface of the heat sink plate and one or more thermoelectric devices of the heat pump. The one or more thermoelectric devices may include one or more thermoelectric elements. Typically, the heat pump includes a thermoelectric device having an array of thermoelectric devices thermally coupled between an active surface and a reference surface. In some embodiments, the heat pump may include a plurality of thermoelectric devices, each having one or more thermoelectric elements. It has been found that force or pressure (e.g., compression, tension) applied to a thermally conductive material when clamped can change the inherent thermal conductivity of the material, thereby resulting in uneven temperature distribution and inconsistent heating and cooling of the sample during thermal cycling. Therefore, there is a further need for a heat pump and heat sink assembly that can be clamped and secured within the assembly while still providing a uniform, more consistent temperature distribution for precisely controlled thermal cycling of a sample block.

[0009] On the one hand, the present invention relates to an improved heat pump having a radiator with a thermally conductive plate having a raised central area that is specially shaped to compensate for the uneven distribution of thermal conductivity. The central area can be surrounded by one or more gaps, typically a single continuous gap surrounding a central raised area to improve thermal resistance. However, some embodiments may also include gaps within the raised area. In some embodiments, one or more supports or materials with lower thermal conductivity may also be included within the gap area to improve structural support while maintaining increased thermal resistance. It will be appreciated that the device can be designed without any supports in the gap area.

[0010] In some embodiments, a heat pump includes a planar surface (e.g., a reference surface of a Peltier device) operatively coupled to a plurality of thermoelectric elements; and a heat sink in thermal contact with the planar surface. The heat sink may include a plate of thermally conductive material, the top surface of the plate being thermally coupled to the planar surface. The plate includes an outer periphery corresponding to the size and shape of the planar surface, a central raised region defined in a shape corresponding to the uneven temperature distribution of the planar surface, and a void between the outer periphery and the central raised region. The void substantially surrounds the central raised region to increase thermal resistance in that region. In some embodiments, the void is substantially continuous and may include a partial or nearly complete removal of planar material. In some embodiments, the heat sink plate has a rectangular outer periphery and a central raised region that is substantially elliptical or circular in shape, corresponding to the shape of the uneven temperature distribution. While examples of elliptical and circular shapes are described herein, it should be understood that the raised region may be any shape or combination of shapes that corresponds to the uneven temperature distribution. For example, the raised region may be defined as a square, a rectangle, or even a non-uniform, irregular geometric shape such as a ring or a figure-eight. The shape can be continuous, or can be discontinuous, such as a column, a plurality of shapes of the same or different sizes (e.g., a plurality of rectangles, circles, etc.), or a combination of different shapes. In some embodiments, the heat sink includes one or more supports within the void region to support the thermoelectric element adjacent to the void region. The one or more supports are formed of a material with a lower thermal conductivity than the plate and can be elastic to provide consistent support during expansion and contraction of the thermoelectric element. In some embodiments, the plate can include a recess within the void region to properly accommodate the one or more supports. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a perspective view of a heat sink portion of a thermoelectric device / heat sink assembly according to some embodiments.

[0012] Figure 2 is a side view of a heat sink portion of a sample bulk / thermoelectric device / heat sink assembly according to some embodiments.

[0013] 3A is a perspective view of an example sample block suitable for use with a thermoelectric device / heat sink assembly, according to some embodiments.

[0014] 3B-3C illustrate exemplary clamping mechanisms for securing components of a sample block / thermoelectric device / heat sink assembly.

[0015] Figure 4 is a thermal map showing the heat distribution in an example sample block when thermally cycled by a conventional thermoelectric device / heat sink assembly.

[0016] Figure 5 is a perspective view of an alternative heat sink portion according to some embodiments.

[0017] Figure 6 yes Figure 5 A top view of the alternative heat sink section in Figure 1.

[0018] Figure 7 A conventional sample block is shown with a thermoelectric heat pump underneath.

[0019] Figure 8 Shown is an experimental setup for monitoring the thermal profile of a sample block during thermal cycling.

[0020] Figure 9-10 Experimental results are presented that show the improvement in heat distribution in a sample block when thermally cycled using a heat pump according to aspects of the present invention.

[0021] Figure 11-13 Alternative embodiments of heat sink portions of thermoelectric device / heat sink assemblies according to some embodiments are shown, having different regular, irregular, and non-uniform shapes, sizes, and numbers of central raised portions. DETAILED DESCRIPTION

[0022] Heat pumps for thermal circulation of biological samples utilize thermoelectric devices, typically Peltier devices or Peltier thermoelectric devices, which are single electronic devices that exploit the well-known Peltier effect to induce heat flow in either of two opposing directions, depending on the direction of current passing through the device. The present invention is applicable to systems comprising one or more such thermoelectric devices, but any type of heat pump device can be utilized. Each thermoelectric device is typically rectangular in shape, and when two or more thermoelectric devices are present, they are typically arranged serially in a rectangular array. When an array of thermoelectric devices is used, the array preferably includes two to twenty thermoelectric devices, and in a preferred embodiment, four to ten thermoelectric devices. The term "thermoelectric device" is used herein to include both a single thermoelectric device and an array of thermoelectric elements and associated planar surfaces. The thermoelectric device or array of such devices is arranged to form a planar surface in contact with the sample block, and heat is actively transferred across the area between the sample block and the thermoelectric device through the planar surface. The sample block can be coextensive with or extend beyond the planar area occupied by the thermoelectric device.

[0023] As used herein, the term "void" or "void area" refers to an area in the thermally conductive plate of a heat sink that has been removed or left open, i.e., a discontinuity is formed in the thermally conductive plate material and is typically filled with air. The term "void" also refers to a depression that extends only partially through the plate and is therefore open only to one side of the plate, preferably the side facing the thermoelectric device, and can also include the complete removal of material (e.g., extending through the thickness of the plate and open on both sides of the plate). The void can be a reduction in thickness of up to 50%, 75%, 90%, or substantially complete removal of one or more portions of the plate. The void is coextensive with the area occupied by one or more thermoelectric elements that are not in contact with the plate. In some embodiments, all or a portion of the void can be filled with a non-conductive material or support.

[0024] The plate and the heat sink as a whole, including the plate and fins, can be any thermally conductive material and, preferably, made of a metal or metal alloy. Aluminum, copper, and stainless steel are examples; other examples will be apparent to those familiar with the manufacture and / or use of thermal cyclers. The plate can be integrated with the fins, or the plate and fins can be manufactured as separate pieces that are joined by welding or other conventional joining means to achieve a thermal interface, meaning that the nature of the contact is such that heat transfer across the interface is substantially unimpeded by the interface itself. Despite the use of different materials, the contact between the plate and the thermoelectric device is also a thermal interface. To achieve a thermal interface between the plate and the thermoelectric device, materials such as GRAFOIL (UCAR Company, Inc., Wilmington, Delaware, USA), Tgon (Laird Technologies), various thermal greases, or any suitable material can be placed between these components.

[0025] Due to the nonlinear behavior of thermo-material interfaces exposed to clamping pressure, it was found that the thermal uniformity of the sample block can be altered depending on the uniformity of the applied clamping force. The thermal resistance of a thermo-material interface such as Grafoil decreases exponentially with increasing pressure. Therefore, along certain areas where the clamping force is significantly higher than in the middle (e.g., at the corners and along the edges of the sample block), there is more heat flux through the thermoelectric elements to the heat sink. This results in the edge and corner regions being cooler than the middle region, which can adversely affect the uniformity of the bioproduct during thermal cycling. In the case of clamping a rectangular heat sink plate to a rectangular array of thermoelectric elements, an elliptical shape of thermal uniformity was observed in the sample block (see Figure 4 To mitigate or compensate for this anomaly, a heat sink plate surrounded by a void (see Figure 1 and 5An elliptical central region is formed on the base of the thermoelectric element (in the embodiment in FIG). The void limits thermal conduction and therefore limits heat loss through the thermoelectric element, keeping the edges desirably warm, which results in a more uniform thermal distribution of the sample block. The void can be formed by removing material from the top surface, such as by machining or any suitable method, such that the thickness of the plate decreases along the void region. In some embodiments, the heat sink can include one or more supports, such as O-rings, within the void that have a lower thermal conductivity than the plate material. In other embodiments, the void can be partially or completely filled with a material (e.g., ceramic, elastomer) that has a lower thermal conductivity than the plate material.

[0026] While the features defining the invention can be embodied in a variety of configurations, the invention as a whole will be best understood through a detailed description of specific embodiments thereof. Several such embodiments are illustrated in the drawings.

[0027] Figure 1 An exemplary heat sink 10 for a heat pump according to aspects of the present invention is shown. The heat sink includes a plate 11 of thermally conductive material having a raised area 12 for placement against a flat surface of the heat pump and heat dissipating fins 18 on an underside opposite the plate. The outer periphery 14 of the raised portion 12 is substantially the same size as the area occupied by the thermoelectric device. The raised portion 12 includes a raised central region 13 defined as an ellipse and surrounded by a void region 15 that surrounds the raised central region 13 and is substantially continuous.

[0028] Figure 2 A side view of heat sink 10 is shown, wherein raised area 12 of plate 11 has an array of thermoelectric devices 20 above it as seen from the side, with the thermoelectric devices themselves elevated a short distance above the plate to emphasize that the plane formed by the surfaces of the thermoelectric devices 20 is coextensive with the raised area 12 of the plate. In use, the thermoelectric devices 20 are in direct contact with the raised area 12 of the plate. Figure 2 Also shown are cooling fins 18 which together with plate 11 form a heat sink. Above thermoelectric device 20 is sample block 30 which is also held in direct contact with the active surface of thermoelectric device 20 to provide uniform, precisely controlled thermal cycling for the sample held within sample block 30.

[0029] like Figure 1 As shown, the void region in this embodiment is a single continuous void defined as an ellipse around the central raised region 12. This shape corresponds to the shape of the uneven temperature distribution of a rectangular plate without any voids (e.g., Figure 4(See Figure 11). When plate 11 is clamped between a thermoelectric device and a sample block, the forces applied to the plate are generally more concentrated along the corners and outer perimeter. Therefore, including a continuous void surrounding the edge and corner regions reduces thermal conductivity in these regions, thereby providing a more uniform temperature across the sample block. While the raised central region 13 is shown here as an oval, it should be understood that the raised central region 13 may be defined as a variety of other shapes depending on the size of the plate. For example, the raised region 112 may be formed as a circle (e.g., corresponding to a square plate).

[0030] An example of a sample block is shown in FIG3A , which can be further understood by reference to U.S. Patent No. 7,955,573 , the entire contents of which are incorporated herein by reference for all purposes. FIG3A is a perspective view of a sample block 30 having a 12×8 array of 55 wells at a standard spacing. The block is a single piece of machined metal with a relatively thick base 31 that is slightly longer and wider than the rest of the block, forming a flange 32. A groove 34 surrounds the edge of the base to accommodate an O-ring and engages the outer perimeter of the entire plate. A central section of the block, bounded by the flange, rises to the block's top surface 33. Top surface 33 is flat and planar, interrupted by openings for sample wells 35. Beneath top surface 33 lies a network of hollow channels. Additional openings 36 positioned between sample wells 35 open the hollow sections to the block's top surface 33. A central platform 37 occupies the space otherwise occupied by mass-reducing holes 36 and facilitates alignment. Typically, the sample block 30 serves as a support block for a disposable plastic well plate member (not shown) having a plastic well corresponding to each well 34 in the block. While a particular sample block is shown here, it should be understood that the concepts described herein are applicable to various other assemblies utilizing sample blocks having different configurations, sizes, well counts, and shapes (e.g., square).

[0031] Figures 3B-3C illustrate an exemplary clamping mechanism for securing components of a sample block / thermoelectric device / heat sink assembly. Preferably, the clamping mechanism applies sufficient clamping force to securely engage the components, thereby ensuring a consistent thermal interface between adjacent components. To further improve thermal non-uniformity in the heat pump, a highly thermally conductive material such as synthetic graphite (e.g., Tgon) can be used as the thermal interface between components, which, due to its thermal properties, can more evenly distribute heat. In the embodiment shown in Figures 3B-3C, the heat pump assembly is clamped together by means of four precision shoulder screws 40. Each screw 40 clamps a retaining ring 43 against Figure 2Heat sink 10 is shown. The clamping force is determined by a stack of four disc springs 42, as shown in FIG3C . As a result, sample block 30, heat pump 20, any thermal interface material (if present), and heat sink 10 are held together by a predetermined force. In some embodiments, a thermistor is embedded in the bottom of the sample block, which can be used to read and control the sample block's temperature. For example, six thermistors can be used to determine / monitor temperature distribution. Variations in the disc springs result in some variation in the clamping force at each screw location, resulting in some uneven clamping force. This variation can lead to thermal non-uniformity, which is addressed by the improved heat sink / heat pump configuration described herein. While a specific clamping configuration is described herein, it is understood that the problem of non-uniformity caused by variations in clamping force also exists with various other clamping methods. Other clamping mechanisms may include fewer or more screws, alternative fasteners (e.g., snap fit, interference fit), and screws or fasteners in other locations (e.g., a central screw extending through the center of the assembly). It is understood that aspects of the improved heat pump and heat sink described herein can be modified as needed to address the details of any clamping method.

[0032] Figure 4 A thermal image of the sample block described above during thermal cycling within an assembly utilizing a conventional heat pump having a heat sink with a solid raised portion coextensive with the sample block is shown. The thermal image shows a different temperature distribution in region A. Notably, the corner regions and outer perimeter, where greater clamping force is applied, have reduced thermal resistance, resulting in cooler regions that adversely affect thermal cycling of individual samples within the sample wells of the sample block.

[0033] In some embodiments, to further improve thermal uniformity, a special thermal material interface is used, such as synthetic graphite (e.g., Tgon from Laird Technologies). Advantageously, Tgon is sufficiently compliant to compensate for any surface irregularities while having four times the through-thickness and ten times the in-plane thermal conductivity of copper.

[0034] On the other hand, because the thermoelectric elements expand, contract, and flex above the void area, one or more supports may be positioned within the void area to provide appropriate support for the thermoelectric elements above the void area. Such supports may be formed of a material having low thermal conductivity and / or an elastic material to provide support while allowing for expansion and contraction of the respective thermoelectric elements. The supports may be configured as one or more rubber O-rings, such as square profile O-rings, sized to fit within each corner. It will be understood that the supports need not be circular and may be any desired shape (e.g., square, rectangular, triangular, any suitable shape, and / or any combination of shapes). Such embodiments may be used in Figure 5-6 Shown in.

[0035] Figure 5 A heat sink 10' is shown having a rectangular plate 12 with a raised interior region wherein an elliptical raised central region 13 is surrounded by a void region 15 between a perimeter 14 and the raised central region 13. Circular recesses 16 have been machined in each corner for inserting an O-ring 17 to facilitate assembly, as shown. Figure 6 Although a rubber O-ring is described herein, it will be appreciated that various other shapes and materials may be used. In other embodiments, the void may be partially or completely filled with any suitable low thermal conductivity and / or elastic material.

[0036] Figure 7-8 An experimental setup is shown to demonstrate the use and advantages of the heat pump configuration described above. Figure 7 Two sample blocks with underlying thermoelectric element arrays are shown. Each array has approximately 20 heat pumps. The device assembly on the left includes a sample block 31 with 96 wells, while the device on the right includes a sample block 32 with 384 wells. The thermal uniformity of the sample blocks is measured using 15 temperature probes 40, as shown in Figure 1. Figure 8 The experimental results show that by using the improved heat pump with an elliptical raised central area surrounded by a void area, the thermal non-uniformity is reduced by 35-40%, for example Figure 1 and Figure 5 As shown in .

[0037] A typical thermal trace for a system operating with a conventional solid heat sink is Figure 9 The thermal trace of the system modified with an oval heat sink is shown in Figure 10 Shown in.

[0038] Figure 11 Shows something like Figure 1 FIG. 1 is a perspective view of a heat sink portion 10 ″ of a thermoelectric device / heat sink assembly in FIG. 1 , however, according to some embodiments, the central raised portion 13 is rectangular in shape.

[0039] Figure 12 FIG10 shows a perspective view of a heat sink portion 10'' of a thermoelectric device / heat sink assembly according to some embodiments, which has a central raised portion 13 of multiple non-continuous shapes, including irregular shapes and multiple circular shapes of different sizes.

[0040] Figure 13 A perspective view of a heat sink portion 10'''' of a thermoelectric device / heat sink assembly is shown having a central raised portion 13 in the shape of a non-uniform annulus with an internal void within the raised area, according to some embodiments.

[0041] While the foregoing description describes various alternatives, other alternatives will be apparent to those skilled in the art and are within the scope of the invention.

[0042] In the appended claims, the terms "a" or "an" are intended to mean "one or more". The term "comprising" and its derivatives, such as "including" and "comprising", when preceding the recitation of a step or element, are intended to indicate that the addition of other steps or elements is optional and not precluded. All patents, patent applications, and other published references cited in this specification are incorporated herein by reference in their entirety. Any discrepancies between any reference cited herein and the explicit teachings of this specification are intended to be resolved in favor of the teachings in this specification. This includes any discrepancies between the art-understood definition of a word or phrase and the definition of the same word or phrase explicitly provided in this specification.

Claims

1. A heat pump comprising: a plurality of thermoelectric devices having one or more thermoelectric elements defining a plane; as well as A heat sink is disposed below the plurality of thermoelectric devices, the heat sink comprising: a plate of thermally conductive material, the plate having a raised portion having a top surface thermally coupled to the planar surface of the one or more thermoelectric elements, wherein the raised portion of the plate comprises: an outer periphery and a central raised area, the central raised area being shaped to correspond to the uneven temperature distribution of the plane, a void area between the outer periphery and the central raised area, wherein The void region substantially surrounds the central raised region and is substantially continuous around the central raised region; and One or more supports, the one or more supports being made of a material having a lower thermal conductivity than the plate, wherein the one or more supports are disposed within the void area.

2. The heat pump according to claim 1, wherein The heat sink also includes a plurality of heat dissipation fins thermally coupled to an underside of the plate opposite the raised portion.

3. The heat pump according to claim 1 or 2, characterized in that The outer periphery of the plate is rectangular in shape and the central raised area is generally oval or circular in shape.

4. The heat pump according to claim 1 or 2, characterized in that The central raised area is generally rectangular in shape.

5. The heat pump according to claim 1 or 2, characterized in that The central raised area is a combination of shapes.

6. The heat pump according to claim 1 or 2, characterized in that The central raised area is irregular or non-uniform in shape.

7. The heat pump according to claim 1, wherein The void region includes an area of ​​reduced thickness such that the planar surface does not contact the plate within the void region.

8. The heat pump according to claim 7, wherein The void region comprises a thickness that is 50% or less than a thickness of the central raised region.

9. The heat pump according to claim 7, wherein The void region comprises a thickness that is 25% or less of a thickness of the central raised region.

10. The heat pump according to claim 7, wherein The void region comprises a thickness that is 10% or less of a thickness of the central raised region.

11. The heat pump according to claim 7, wherein The void region is a single continuous void surrounding the central raised region.

12. The heat pump according to claim 7, wherein The void region is a plurality of voids.

13. The heat pump according to claim 1, wherein The plate is sized such that a top surface of the outer periphery of the plate is coextensive with the outer periphery of the planar surface.

14. The heat pump according to claim 1, wherein The one or more supports support one or more thermoelectric elements facing the void region.

15. The heat pump according to claim 14, wherein The plate further includes a recess defined within the void area, wherein the recess is defined to suitably receive the one or more supports.

16. The heat pump according to claim 14, wherein Each of the one or more supports comprises a resilient material.

17. The heat pump according to claim 16, wherein Each of the one or more bearings includes a rubber O-ring.

18. The heat pump according to claim 1, wherein The periphery of the raised portion is rectangular in shape, and the shape of the central raised area is generally elliptical or circular, The one or more supports include at least four supports, and the at least four supports are arranged in the gap area along four inner corners of the rectangular periphery.

19. The heat pump according to claim 18, wherein Each of the one or more supports comprises a resilient material.

20. The heat pump according to claim 19, wherein Each of the one or more bearings includes a rubber O-ring.

21. The heat pump according to claim 18, wherein The interstitial region is partially or completely filled with a material having low thermal conductivity.

22. The heat pump according to claim 1, wherein Also includes: A thermal interface material is disposed between the heat sink and the plurality of thermoelectric devices.

23. The heat pump according to claim 22, wherein The thermal interface material includes synthetic graphite.

24. A temperature control assembly for thermal cycling of a multi-vessel sample block, the assembly comprising: a plurality of thermoelectric devices comprising one or more thermoelectric elements operatively coupled between an active surface for thermally coupling to the sample block and a reference surface for thermally coupling to a heat sink; a heat sink disposed below the plurality of thermoelectric devices, the heat sink comprising a plate of thermally conductive material having a raised portion, the top surface of the raised portion being thermally coupled to the planar surfaces of the plurality of thermoelectric elements, wherein the raised portion comprises: a rectangular outer perimeter contacting and coextensive with the plane, a central raised area defined in a shape corresponding to the uneven temperature distribution of the one or more thermoelectric elements, and a void area between the outer periphery and the central raised portion, wherein the void area surrounds the central raised area, one or more supports, the one or more supports being made of a material having a lower thermal conductivity than the plate, wherein the one or more supports are disposed within the void area; and A plurality of heat dissipation fins are thermally coupled to an underside of the plate opposite the raised portion of the plate.

25. The assembly of claim 24, wherein The central raised area comprises a rounded, circular or oval shape.

26. An assembly according to claim 24 or 25, characterized in that The one or more supports include at least four supports made of a material having a lower thermal conductivity than the plate, the at least four supports being disposed within the void area along four inner corners of the outer periphery of the rectangle.

27. The assembly of claim 26, wherein The plate includes at least four pockets defined within the void area, wherein the pockets are sized to suitably receive the at least four supports.

28. The assembly of claim 27, wherein The at least four supports comprise an elastic material.

29. The assembly of claim 28, wherein The at least four supports include rubber O-rings.

30. The assembly of claim 24, wherein Also includes: A thermal interface material is disposed between the plurality of thermoelectric devices and the heat sink.

31. The assembly of claim 30, wherein The thermal interface material includes synthetic graphite.

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