Patent Publication Number: US-2019181323-A1

Title: Flexible thermoelectric module

Description:
TECHNICAL FIELD 
     The present disclosure relates to thermoelectric modules, devices, and tapes. 
     BACKGROUND 
     Thermoelectric power generators have been investigated to utilize temperature gradients for electrical energy generation. Traditionally, the thermoelectric generator has n-type and p-type materials, which create electric potential according to temperature gradients or heat flux through the n-type and p-type materials. There have been various efforts to harvest heat waste for renewable energy in a wide range of applications. For example, if the heat energy is dissipated from pipes, energy can be collected directly from the surface of the pipes. In addition, the harvested energy can be utilized for operating wireless sensors that are capable of detecting leaks on connections and various locations along the pipes. 
     SUMMARY 
     At least some aspects of the present disclosure direct to a flexible thermoelectric module made by a process comprising the steps of: providing a flexible substrate having a first surface and an opposing second surface; applying a first patterned conductive layer to the first surface of the flexible substrate, wherein the pattern of first conductive layer forms a first array of connectors and each connector has two ends; generating a plurality of vias on the flexible substrate by removing materials from flexible substrate, wherein at least some of the vias are positioned corresponding to ends of first array of connectors; filling at least some of the vias with a thermoelectric material; applying a second patterned conductive layer to the second surface of the flexible substrate, wherein the pattern of the second conductive layer forms a second array of connectors and each connector has two ends, and wherein at least some of the ends of the second array of connectors are positioned corresponding to at least some of the vias. 
     At least some aspects of the present disclosure direct to a flexible thermoelectric module made by a process comprising the steps of: providing a flexible substrate having a first surface and an opposing second surface; applying a first patterned conductive layer to the first surface of the flexible substrate, wherein the pattern of the first conductive layer forms a first array of connectors and each connector has two ends; generating a plurality of vias on the flexible substrate by removing materials from flexible substrate, wherein at least some of the vias are positioned corresponding to ends of first array of connectors; filling at least some of the vias with an electrically conductive material; placing thermoelectric elements on the second surface of the substrate aligning with the vias; printing a second patterned conductive layer on top of the thermoelectric elements, wherein the pattern of the second conductive layer forms a second array of connectors and each connector has two ends, and wherein at least some of the ends of the second array of connectors are positioned corresponding to at least some of the thermoelectric elements. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, explain the advantages and principles of the invention. In the drawings, 
         FIG. 1A  is a perspective view of one example schematic embodiment of a thermoelectric module;  FIG. 1B  is atop view of the thermoelectric module illustrated in  FIG. 1A ; and  FIG. 1C  is a cross sectional view of the thermoelectric module illustrated in  FIG. 1A ; 
         FIG. 1D  is a cross-sectional view of another example embodiment of a thermoelectric module; 
         FIG. 1E  is a cross-sectional view of yet another example embodiment of a thermoelectric module; 
         FIG. 2A  is a cross-sectional view of one example embodiment of thermoelectric module; 
         FIG. 2B  is a cross-sectional view of another example embodiment of thermoelectric module; 
         FIG. 2C  is a cross-sectional view of one other example embodiment of thermoelectric module; 
         FIGS. 3A-3E  illustrate one embodiment of thermoelectric tape and how it can be used; and 
         FIGS. 4A-4D  illustrate flow diagrams of example processes of making thermoelectric modules. 
     
    
    
     In the drawings, like reference numerals indicate like elements. While the above-identified drawings, which may not be drawn to scale, set forth various embodiments of the present disclosure, other embodiments are also contemplated, as noted in the Detailed Description. In all cases, this disclosure describes the presently disclosed disclosure by way of representation of exemplary embodiments and not by express limitations. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of this disclosure. 
     DETAILED DESCRIPTION 
     Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range. 
     As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise. 
     Spatially related terms, including but not limited to, “lower,” “upper,” “beneath,” “below,” “above,” and “on top,” if used herein, are utilized for ease of description to describe spatial relationships of an element(s) to another. Such spatially related terms encompass different orientations of the device in use or operation in addition to the particular orientations depicted in the figures and described herein. For example, if an object depicted in the figures is turned over or flipped over, portions previously described as below or beneath other elements would then be above those other elements. 
     As used herein, when an element, component or layer for example is described as being “on” “connected to,” “coupled to” or “in contact with” another element, component or layer, it can be directly on, directly connected to, directly coupled with, in direct contact with, or intervening elements, components or layers may be on, connected, coupled or in contact with the particular element, component or layer, for example. When an element, component or layer for example is referred to as being “directly on,” “directly connected to,” “directly coupled to,” or “directly in contact with” another element, there are no intervening elements, components or layers for example. 
     Thermoelectric devices, also referred to as thermoelectric modules, can be used as a power source for wearable devices and wireless sensors, as well as a cooling source for temperature controlling applications. A thermoelectric module converts temperature difference to electric power and typically includes a number of n-type and p-type thermoelectric elements electrically connected to generate the electrical power. For example, the thermoelectric modules can utilize body heat to generate power for wearable electronics, such as healthcare monitoring watches. In addition, the thermoelectric modules can be used as power sources to patch-type sensors, which are attached on an animal or human body to monitor health signals, for instance, electrocardiography (ECG) monitoring. The thermoelectric devices and modules can be used in either electrical power generation or cooling applications. Some aspects of the present disclosure are directed to flexible thermoelectric modules. In some embodiments, the thermoelectric module is thin, for example, with a thickness no more than 1 mm. In some cases, the thermal resistance of the thermoelectric module matches with the thermal resistance of the heat source, such that an optimum electrical power conversion is achieved. In some embodiments, the unit area thermal resistance of the flexible thermoelectric module is about 0.5 K-cm 2 /W, which is close to a value for the unit area thermal resistance commonly associated with liquid heat exchangers. In some embodiments, the unit area thermal resistance of the flexible thermoelectric module is less than 1.0 K-cm 2 /W. Since the flexible thermoelectric module can match the (relatively low) unit area thermal resistance of liquid heat exchangers, the flexible thermoelectric module can effectively generate electrical power even with these relatively high-flux sources of heat. 
     Some aspects of the present disclosure are directed to thermoelectric tapes, where each tape has a plurality of thermoelectric modules. In some cases, the thermoelectric tape includes a plurality of thermoelectric modules connected in parallel. In some cases, a section of the thermoelectric tape can be separated from the tape and used as a power source. In some cases, the thermoelectric tape includes two wires that can be used to output the generated power. 
       FIG. 1A  is a perspective view of one example schematic embodiment of a thermoelectric module  100 A;  FIG. 1B  is a top view of the thermoelectric module  100 A; and  FIG. 1C  is a cross sectional view of the thermoelectric module  100 A. In some cases, the thermoelectric module  100 A is flexible. The thermoelectric module  100 A includes a substrate  110 , a plurality of thermoelectric elements  120 , a first set of connectors  130 , and a second set of connectors  140 . In some embodiments, the substrate  110  is flexible. In the embodiment illustrated in  FIG. 1A , the substrate  110  includes a plurality of vias  115 . In some cases, at least some of the vias are filled with an electrically conductive material  117 . The flexible substrate  110  has a first substrate surface  111  and a second substrate surface  112  opposing to the first substrate surface  111 . The plurality of thermoelectric elements  120  includes a plurality of p-type thermoelectric elements  122  and a plurality of n-type thermoelectric elements  124 . 
     In some embodiments, the plurality of thermoelectric elements  120  are disposed on the first surface  111  of the flexible substrate. In some embodiments, at least part of the plurality of p-type and n-type thermoelectric elements ( 122 ,  124 ) are electrically connected to the plurality of vias, where a p-type thermoelectric element  122  is adjacent to an n-type thermoelectric element  124 . In some cases, the first set of connectors  130 , also referred to as electrodes, are disposed on the second surface  112  of the substrate  110 , where each of the first set of connectors is electrically connected to a first pair of adjacent vias  115 . In some cases, the second set of connectors  140  are disposed on the plurality of p-type and n-type thermoelectric elements ( 122 ,  124 ), where each of the second set of connectors is electrically connected to a pair of adjacent p-type and n-type thermoelectric elements. In some embodiments, the second set of connectors  140  are printed on the thermoelectric elements  120 . The flow of current in the thermoelectric and the flow of heat in this example thermoelectric module is generally transverse to or perpendicular to the substrate  110  when the thermoelectric module  100  is in use. In some embodiments, a majority of heat propagates through the plurality of vias  115 . 
     In some embodiments, the thermoelectric module  100  is used with a predefined thermal source (not illustrated), and the thermoelectric module has a thermal resistance having an absolute difference no more than 10% from a thermal resistance of the predefined thermal source. In some embodiments, the thermoelectric module has a thermal resistance having an absolute difference no more than 20% from a thermal resistance of the predefined thermal source. In some embodiments, the thermoelectric module  100  is designed to have a matching thermal resistance equal to that of the thermal resistance of the rest of the passive components transferring heat. The thermal resistance can be changed by the packing density of thermoelectric elements, dimensions of the thermoelectric elements, for example. 
     In some embodiments, the substrate  110  can be a flexible substrate. In some implementations, the substrate  110  can use polymer materials such as, for example, polyimide, include polyethylene, polypropylene, polymethymethacrylate, polyurethane, polyaramide, liquid crystalline polymers (LCP), polyolefins, fluoropolymer based films, silicone, cellulose, or the like. The thickness of the substrate  110  can be in a range between 20 micrometers and 200 micrometers. In some cases, the thickness of the substrate  110  can be less than 100 micrometers. In some embodiments, the substrate  110  can include a plurality of vias  115 . The vias  115  are usually openings through the substrate. In some cases, the plurality of vias  115  are disposed in generally equal spacing in the substrate. The width of the vias  115  can vary in the range of 0.05 mm to 5 mm, or in the range of 0.5 mm to 2 mm, or in the range of 0.1 to 0.5 mm. The spacing between adjacent vias can vary in the range of 100 μm to 10 mm, or in the range of 1 mm to 5 mm. The vias can be formed with various techniques, for example, such as laser drilling, die cutting, ion milling, or chemical etching, or the like. More techniques on forming and configurations vias or cavity in a substrate is provided in U.S. Publication No. 2013/0294471, which is incorporated by reference in its entirety. 
     In some cases, the axes of the vias  115  are generally perpendicular to the major plane of the substrate  110 . In some cases, the axes of the vias  115  are can be at an angle between 25° to 90° from the major plane of the substrate. In one embodiment, the axes of the vias  115  are at an angle in the range of 25° to 40° from the major plane of the substrate. In some embodiments, the vias  115  can be filled with a conductive material  117 , for example, a metal, a metal composite, carbon nanotubes composite, multi-layer graphene, or the like. In some embodiments, the vias  115  can be partially filled with copper or another metal and partially filled with a thermoelectric material. In some embodiments, the conductive material  117  includes no less than 50% of copper. 
     The thermoelectric elements  120  can include various thermoelectric materials. In one embodiment, the thermoelectric material is a chalcogenide such as Bi2Te3, Sb2Te3, or alloys thereof. In another embodiment, the thermoelectric material is an organic polymer such as PEDOT (poly(3,4-ethylenedioxythiophene)), or an organic composite such as PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate). In another embodiment, the thermoelectric material is a chalcogenide superlattice, formed on a silicon wafer, and diced into die before assembling onto the substrate  110 . In another embodiment, the thermoelectric material is a doped form of porous silicon, which is diced into die before assembling onto the substrate  110 . 
     When using organic polymers as a thermoelectric, the required processing temperatures can be decreased when compared to the chalcogenide thermoelectric material, and a wide variety of less expensive flexible substrate materials become applicable, such as polyethylene, polypropylene, and cellulose. In some cases, by processing chalcogenide materials separately, for example, in superlattice form on a silicon wafer, it is possible to improve the energy conversion efficiency (ZT value) relative to conventional thermoelectric. 
     In some embodiments, the thermoelectric elements  120  can be formed by thermoelectric material printed or dispensed directly on the substrate. In some cases, the thermoelectric elements  120  can be printed or dispensed directly over the vias  115  of the substrate  110 . In some implementations, the thermoelectric elements are formed by printing of a thermoelectric material in paste form. After printing of the thermoelectric, the module is heat-treated so that the binder of the paste will be pyrolyzed and the thermoelectric particles sintered into a solid body. This embodiment allows for a very thin thermoelectric material in the module, with thicknesses in the range of 0.01 to 0.10 mm. 
     The thermoelectric elements  120  can be fabricated in a variety of ways including, for example, thin film processing, nano-material processing, micro-electro-mechanical processing, or tape casting. In one example, the starting substrate can be a silicon wafer with diameters in the range of 100 mm to 305 mm (4″ to 12″) and with thicknesses in the range between 0.1 and 1.0 mm. In some embodiments, thermoelectric materials can be deposited onto the starting substrate by means of, for example, sputtering, chemical vapor deposition, or molecular beam epitaxy (MBE). In one embodiment, the thermoelectric elements  120  can be formed as a chalcogenide superlattice by means of MBE. Examples of these superlattice structures for thermoelectric applications include Bi2Te3/Sb2Te3 superlattices and PbTe/PbS superlattices. By appropriate doping, both n and p-type thermoelectric superlattices can be produced. After deposition, the silicon wafer can be diced into thermoelectric elements  120  for mounting onto the substrate  110 . The width of the thermoelectric elements  120  can be in the range of 0.05 to 5 mm, preferably in the range of 0.1 to 1.0 mm. 
     In some embodiments, the silicon wafer is used as a substrate for the formation of silicon nanofilaments, nanoholes, or other nanostructures, such as porous silicon. The silicon nanostructures can in turn be chemically modified, for instance through the formation of magnesium, lead, or bismuth silicide phases. By appropriate doping, both n and p-type thermoelectric nanostructures can be produced. After formation of nanostructures, the silicon wafer can be diced into thermoelectric elements  120  for mounting onto a polymer substrate. In some embodiments, the thermoelectric materials can be removed from the silicon substrate as a transfer layer before bonding to the substrate  110 , in which case the thickness of the thermoelectric element layer to be bonded can be in the range of 0.01 to 0.2 mm. 
     In another embodiment, the thermoelectric elements can be formed from a tape casting process. In tape casting an inorganic precursor material, in the form of a paste, is cast or silk-screened onto a smooth refractory setter, such as alumina, aluminum nitride, zirconia, silicon carbide, molybdenum. The tape is then sintered at high temperature to form the desired thermoelectric compound, in thicknesses that range from 0.1 to 5.0 mm. After sintering, the tape can be diced thermoelectric elements  120  for mounting onto the substrate  110  in die form. 
     In some embodiments, the first set of connectors can be formed from a metal, for example, copper, silver, silver, gold, aluminum, nickel, titanium, molybdenum, or the like, or a combination thereof. In one embodiment, the first set of connectors are formed from copper. For example, the connectors can be formed by sputtering, by electrodeposition, or by lamination of copper sheets. In some implementations, the copper pattern can be defined photolithographically using a dry film resist, followed by etching. The thickness of the first set of connectors  130  can range from 1 micrometer to 100 micrometers. In one embodiment, a polyimide substrate  110  with copper connectors  130  can use flexible printed circuit technology. Details on flexible circuit technology are provided in U.S. Pat. Nos. 6,611,046 and 7,012,017, which are incorporated by reference in their entireties. 
     Disposed over the top of the thermoelectric elements  120  are a set of second connectors  140 . The connectors  140  can be formed, for example, from a deposited or printed metal pattern. The metal can be, for example, copper, silver, gold, aluminum, nickel, titanium, molybdenum, or combinations thereof. In some embodiments, the metal pattern is formed by silk screen printing using a metal-composite ink or paste. In other embodiments, the metal pattern can be formed by flexographic printing or gravure printing. In some embodiments, the metal pattern can be formed by ink printing. In yet some other embodiments, the metal pattern can be deposited by means of sputtering or chemical vapor deposition (CVD) followed by photolithographic patterning and etching In some embodiments, the connectors  140  may have thicknesses in the range of 1 micrometer to 100 micrometers. In some implementations, the thickness of the thermoelectric module  100 A is no greater than 1 mm. In some implementations, the thickness of the thermoelectric module  100 A is no greater than 0.3 mm. In some cases, the thickness of the thermoelectric module  100 A in a range between 50 micrometers and 500 micrometers. 
     In some embodiments, at least each of a part of the two sets of connectors ( 130 ,  140 ) makes an electrical connection between two adjacent thermoelectric elements—one p-type thermoelectric element and one n-type thermoelectric element. In one embodiment, a connector  130  electronically connects a first pair of thermoelectric elements and a connector  140  electronically connects a second pair of thermoelectric elements, where the first pair of thermoelectric elements and the second pair of thermoelectric elements have one thermoelectric in common. In some cases, the spacing between two adjacent thermoelectric elements  120  can partially depend on the connectors ( 130 ,  140 ) placement accuracy. In one example embodiment, the connector placement accuracy is 10 micrometers and the spacing between two adjacent thermoelectric elements  120  is 10 micrometer. 
     In some embodiments, the thermoelectric module  110 A includes bonding components  150 . In the embodiment illustrated in  FIG. 1C , the bonding components are disposed between the thermoelectric elements  120  and the vias  115  filled with conductive material. In some embodiments, the bonding components  150  can include a bonding material including, for example, a solder material, a conductive adhesive, or the like. In one embodiment, the bonding material can be a solder material containing various mixtures of lead, tin, bismuth, silver, indium, or antimony. In another embodiment, the bonding material can be an anisotropic conductive adhesive, for example, the 3M adhesive 7379. 
     In some embodiments, the width of the bonding components  150  is greater than the width of the vias  115 . In some embodiments, the width of the thermoelectric elements  120  is greater than the width of the vias  115 . In one embodiment, the difference in width between the thermoelectric elements and the vias is no less than the thickness of the thermoelectric elements. As an example, if the thickness of the thermoelectric elements is 80 micrometers, the difference in width between the thermoelectric elements and the vias is at least 80 micrometers. In one embodiment, the width of the thermoelectric elements is substantially equal to the width of the vias. 
     In some embodiments, disposed in the spaces between the thermoelectric elements  120  is an insulator  160 . In some cases, the insulator  160  can protects the sides of the thermoelectric elements  120  during a final metallization step. In some cases, the insulator  160  fills spaces between the thermoelectric elements and does not make contact with the top of the thermoelectric elements  120 . In some other cases, the insulator  160  covers a portion of the top of the thermoelectric elements  120 . In one embodiment, the insulator  160  is a low temperature fusible inorganic material which can be applied as a paste or ink by means of silk screening or drop-on-demand (ink-jet) printing. An example would be a paste made from a boron or sodium doped silicate or glass frit material. After printing, the glass frit can be melted in place to form a seal around the thermoelectric elements. In some embodiments, the insulator  160  is an organic material that can be applied by a silk screen printing process, a drop-on-demand printing process, or by flexographic or gravure printing. Examples of printable organic insulator materials include acrylics, polymethylmethacrylate, polyethylene, polypropylene, polyurethane, polyaramide, polyimide, silicone, and cellulose materials. In another embodiment, the insulator is a photo-imageable organic dielectric material, such as a silsesquioxane, benzocyclobutane, polyimide, polymethylmethacrylate, or polybenzoazole. In another embodiment, the insulator  160  is formed as a spin-on glass using precursors such as, for example, a meth-alkyl or meth-alkoxy siloxane compound. After deposition, the spin-on glass can be patterned using a photoresist and etching technique. 
     In some implementations, an array of “drop-on-demand” nozzles can be used to apply the insulator  160  of a low-viscosity dielectric liquid solution directly to the substrate at several sites across the thermoelectric module  110 A. The liquid will flow and be distributed within spaces between adjacent thermoelectric elements by means of capillary pressure. While the liquid insulator  160  flows in microchannels between thermoelectric elements, the liquid insulator  160  is confined to below a level defined by the upper edges of the thermoelectric elements, such that the liquid insulator  160  does not flow onto or cover the top face of the thermoelectric elements  120 . In some cases, the liquid insulator  160  can be a polymeric material dissolved in a carrier solvent or a curable monomer. In some cases, the liquid insulator  160  travels a certain distance from each dispensing site, dictated by rheology, surface energetics and channel geometry. In some cases, the liquid insulator  160  is dispensed at periodic sites in the substrate  110  to ensure a continuous coverage of the spacing among the thermoelectric elements  120 . 
       FIG. 1D  is a cross-sectional view of another example embodiment of a thermoelectric module  100 D. The thermoelectric module  100 D includes a substrate  110 , a plurality of thermoelectric elements  120 , a first set of connectors  130 , and a second set of connectors  140 . Components with same labels can have same or similar configurations, production processes, materials, compositions, functionality and/or relationships as the corresponding components in  FIG. 1A . In some embodiments, the substrate  110  is flexible. In some embodiments, the substrate  110  includes a plurality of vias  115 . The flexible substrate  110  has a first substrate surface  111  and a second substrate surface  112  opposing to the first substrate surface  111 . The plurality of thermoelectric elements  120  includes a plurality of p-type thermoelectric elements  122  and a plurality of n-type thermoelectric elements  124 . 
     In the embodiment illustrated in  FIG. 1D , the thermoelectric elements  120  are disposed within the vias  115 . In some cases, the thermoelectric elements include a thermoelectric material. In one embodiment, the thermoelectric material is a V-VI chalcogenide compound such as Bi 2 Te 3  (n-type) or Sb 2 Te 3  (p-type). The V-VI chalcogenides are sometimes improved through alloyed mixtures such as Bi 2 Te 3-x Se x  (n-type) or Bi 0.5 Sb 1.5 Te 3  (p-type). In another embodiment, the thermoelectric material is formed from an IV-VI chalcogenide material such as PbTe or SnTe or SnSe. The IV-VI chalcogenides can sometimes be improved through doping, such as Pb x Sb 1-x Te or NaPb 20 SbTe 22 . In yet another embodiment, the thermoelectric material is formed from a silicide, such as Mg 2 Si, including doped versions such as Mg 2 Si x Bi10 x  and Mg 2 Si0.6Sn 0.4 . In an alternate embodiment, the thermoelectric material is formed from a clathrate compound, such as Ba 2 Ga 16 Ge 30 . In yet another embodiment, the thermoelectric material is formed from a skutterudite compound, such as BaxLayCo 4 Sb 12  or BaxInyCo 4 Sb 12 . In an alternate embodiment, the thermoelectric material can be formed from transition metal oxide compounds, such as CaMnO 3 , Na x CoO 2  or Ca 3 Co 4 O 9 . 
     In some implementations, the inorganic materials listed above are generally synthesized by means of a powder process. In the powder process, constituent materials are mixed together in powder form according to specified ratios, the powders are then pressed together and sintered at high temperature until the powders react to form a desired compound. After sintering, the powders can be ground and mixed with a binder or solvent to form a slurry, ink, or paste. In some implementations, thermoelectric elements  120  in the form of a paste can be added to the vias  115  in the substrate  110  by means of a silk screen deposition process or by a doctor-blade process. In some implementations, thermoelectric elements  120  can also be placed in the vias  115  by means of a “drop-on-demand” ink jet process. In some implementations, thermoelectric elements  120  can also be added to the vias  115  by means of a dry-powder jet or aerosol process. In some implementations, thermoelectric elements  120  can also be added to the vias  115  by means of flexographic or gravure printing. 
     In an alternative embodiment to the powder synthesis process, thermoelectric particles of the correct stoichiometery can be formed and recovered directly from a solvent mixture by means of reactive precipitation. In another alternative embodiment, the thermoelectric material can react within a solvent and then be held in the solvent as a colloidal suspension for use directly as nano-particle ink. 
     In some cases, after printing of the thermoelectric material into the vias  115 , the substrate  110  is heat-treated so that the binder is pyrolyzed, and the thermoelectric material is sintered into a solid body with bulk-like thermal and electrical conductivity. 
     In one embodiment, the vias  115  in the substrate  110  can be filled with a carbon-based organic material, such as the thiophene PEDOT. In an alternative embodiment, the thermoelectric elements  120  can be formed from a composite such as PEDOT:PSS or PEDOT:ToS. In an alternative embodiment, the thermoelectric elements  120  can be formed from a polyaniline (PANi). In an alternative embodiment, the thermoelectric elements  120  can be formed from a polyphenylene vinylene (PPV). In an alternative embodiment, the thermoelectric elements  120  can be formed by composites between inorganics and organics. In an alternative embodiment, thermoelectric elements  120  can be formed between a conductive organic binder and nano-filaments such as, for example, carbon nanowires, tellurium nanowires, or silver nanowires. In some implementations, thermoelectric elements formed with organic thermoelectric materials can be deposited within the vias  115  by means of either a silk screen process, or by an ink-jet process, or by flexographic or gravure printing. 
       FIG. 1E  is a cross-sectional view of yet another example embodiment of a thermoelectric module  100 E. The thermoelectric module  100 E includes a first substrate  110 , a second substrate  114 , a plurality of thermoelectric elements  120 , a first set of connectors  130 , and a second set of connectors  140 . Components with same labels can have same or similar configurations, production processes, materials, compositions, functionality and/or relationships as the corresponding components in  FIGS. 1A-1C . In some embodiments, one of or both of the substrates ( 110 ,  114 ) are flexible. In some embodiments, both of the substrate ( 110 ,  114 ) includes a plurality of vias  115 . In some cases, a conductive material  117  is disposed in the vias  115 . The plurality of thermoelectric elements  120  includes a plurality of p-type thermoelectric elements  122  and a plurality of n-type thermoelectric elements  124 . 
     In some cases, the thermoelectric elements  120  are bonded over the top of each of the vias  115  filled with the conductive material  117  in the first or bottom substrate  110  via the bonding components  150 . The second substrate  114  is then positioned over the top of the first substrate  110  and bonded via bonding components  150 , such that each one of the vias  115  filled with the conductive material  117  in the second substrate  114  makes electrical contact with one of the thermoelectric elements  120 . 
     In the embodiment illustrated, the connectors ( 130 ,  140 ) are arranged on both the first and second substrates ( 110 ,  114 ) such that a continuous electrical current can flow from one thermoelectric element to another thermoelectric element. In some embodiments, when flowing through the thermoelectric elements, the flow of current within the n-type and p-type die are in opposite directions, for example, the current flows from bottom to the top in the n-type thermoelectric element and from top to bottom in the p-type thermoelectric element. The flow of currents in the thermoelectric and the flow of heat in this example thermoelectric module is generally transverse to or perpendicular to the plane of the two substrates ( 110 ,  114 ). In some embodiments, the insulator  160  is a low temperature fusible inorganic material which can applied as a paste or ink by means of silk screening or drop-on-demand (ink-jet) printing. In some embodiments, the insulator  160  is an insulating material in gas form, for example, air. 
       FIG. 2A  is a cross-sectional view of one example embodiment of thermoelectric module  200 A. The thermoelectric module  200  includes a first substrate  110  having a plurality of vias  115 , a plurality of thermoelectric elements  120  disposed in the vias  115 , a first set of connectors  130 , a second set of connectors  140 , an optional abrasive protection layer  210 , an optional release liner  220  for the abrasive protection layer  210 , an optional adhesive layer  230 , and an optional release liner  240  for the adhesive layer  230 . Components with same labels can have same or similar configurations, production processes, materials, compositions, functionality and/or relationships as the corresponding components in  FIGS. 1A-1E . In the embodiment illustrated, the abrasion protective layer  210  is disposed adjacent to the first sets of connectors  130  and the release liner disposed adjacent to the abrasive protection layer. In some cases, the adhesive layer  230  is disposed adjacent to one of the first and second sets of connectors  140  and the release liner  240  is disposed adjacent to the adhesive layer  230 . In some embodiments, the abrasion protection layer and/or the adhesive layer is selected with a thermally conductive property providing mechanical robustness, for example, carbon nanotube composites or graphene thin films mixed with adhesive materials. 
       FIG. 2B  is a cross-sectional view of one example embodiment of thermoelectric module  200 B. The thermoelectric module  200 B includes a first substrate  110  having a first set of vias  115 , a first set of thermoelectric elements  120  disposed in the first set of vias  115 , a second substrate  250  having a second set of vias  255 , a second set of thermoelectric elements  260  disposed in the second set of vias  255 , a plurality of conductive bonding components  270  sandwiched between the first substrate and the second substrate, a first set of connectors  130 , and a second set of connectors  140 . Components with same labels can have same or similar configurations, production processes, materials, compositions, functionality and/or relationships as the corresponding components in  FIGS. 1A-1E . In some implementations, at least one of the first substrate  110  and the second substrate  250  is flexible. In some cases, each conductive bonding component  270  is aligned to a first via in the first set of vias  115  and a second via in the second set of vias  255 . 
     In some embodiments, the first set of connectors  130  are disposed on a surface of the first substrate  110  away from the bonding components  270  and each of the first set of connectors  130  is electrically connecting to a first pair of adjacent vias  116  of the first set of vias  115 . In some cases, the second set of connectors  140  are disposed on a surface of the second flexible substrate away from the bonding component  270  and each of the second set of connectors is electrically connecting to a second pair of adjacent vias  256  of the second set of vias  255 . In the embodiment illustrated, the first pair of adjacent vias  116  and the second pair of adjacent vias  256  have one via aligned and one via not aligned. As illustrated, current can flow in the directions  281 ,  282  generally perpendicular to the substrates ( 110 ,  250 ). 
     In some embodiments, a different one of p-type thermoelectric element  122  and n-type thermoelectric elements  124  are disposed in two adjacent vias of the first set of vias  115 . In such embodiments, a different one of p-type thermoelectric element  262  and n-type thermoelectric elements  264  are disposed in two adjacent vias of the second set of vias  255 . Further, a via  115  in the first flexible substrate  110  is generally aligned with a via  255  in the second flexible substrate  250  have a same type of thermoelectric element. 
     In some embodiments, an insulating material  280  is disposed between adjacent bonding components  270 . In some embodiments, the bonding components  270  can use a conductive adhesive material, for example, anisotropic conductive film, electrically conductive adhesive transfer tape, or the like. The insulating material  280  can be, for example, polyimide, polyethylene, polypropylene, polyurethane, silicone, or the like. 
       FIG. 2C  is a cross-sectional view of one example embodiment of thermoelectric module  200 C. The thermoelectric module  200 C includes a first substrate  110  having a first set of vias  115 , a first set of thermoelectric elements  120  disposed in the first set of vias  115 , a second substrate  250  having a second set of vias  255 , a second set of thermoelectric elements  260  disposed in the second set of vias  255 , a plurality of conductive bonding components  270  sandwiched between the first substrate and the second substrate, a first set of connectors  130 , and a second set of connectors  140 . Components with same labels can have same or similar configurations, production processes, materials, compositions, functionality and/or relationships as the corresponding components in  FIGS. 1A-1E . In some implementations, at least one of the first substrate  110  and the second substrate  250  is flexible. In some cases, each conductive bonding component  270  is aligned to a first via in the first set of vias  115  and a second via in the second set of vias  255 . 
     In some embodiments, the first set of thermoelectric elements  120  are of a first type of thermoelectric elements, for example, p-type or n-type thermoelectric elements. In such embodiments, the second set of thermoelectric elements  260  are of a second type of thermoelectric elements that is different from the first type of thermoelectric elements. For example, the first type of thermoelectric elements is p-type and the second type of thermoelectric elements is n-type, or vice versa. In the embodiment illustrated, a thermoelectric element of the first type and a first conductive material  117  are disposed in two adjacent vias of the first set of vias  115 . A thermoelectric element of the second type and a second conductive material  257  are disposed in two adjacent vias of the second set of vias  255 . In such embodiment, a via having the thermoelectric element of the first type in the first substrate  110  is generally aligned with a via having the second conductive material  257  in the second substrate  250 . A via having the first conductive material  117  is generally aligned with a via having the thermoelectric element of the second type in the second substrate  250 . In some cases, the first conductive material  117  is the same as the second conductive material  257 . In some cases, the first conductive material  117  is different from the second conductive material  257 . 
     In some embodiments, thermoelectric modules can be provided in a tape form. In some cases, the tape is in a roll form.  FIGS. 3A-3E  illustrate one embodiment of thermoelectric tape  300  and how it can be used.  FIG. 3B  is an exploded view of the thermoelectric tape  300 . In some embodiments, the thermoelectric tape  300  includes a flexible substrate  305 , a plurality of thermoelectric modules  310 , and two conductive buses ( 321 ,  322 ) running parallel longitudinally along the thermoelectric tape. The thermoelectric module  310  can use any configuration of thermoelectric modules described herein. In some cases, the flexible substrate  305  includes a plurality of vias. In some embodiments, the plurality of thermoelectric modules  310  are connected in parallel. The thermoelectric modules  310  generates a certain amount of electric current and voltage for a given temperature gradient. Given the same density of n-type and p-type thermoelectric elements included, the larger sized module provides higher output current and voltage. In addition, a higher density of thermoelectric elements creates higher output voltage. 
     In some cases, the thermoelectric tape  300  includes a thermally conductive adhesive layer  330  disposed on a first surface of the flexible substrate  305 , as illustrated in  FIG. 3B . In some cases, the thermoelectric tape  300  includes an optional protective film  335 . In some embodiments, a stripe of thermal insulating material  341  is disposed longitudinally along the thermoelectric tape  300 . In some cases, two stripes of thermal insulating material  341 ,  342  are disposed longitudinally along the thermoelectric tape  300 , each of the two stripes of thermal insulating material disposed at an edge of the thermoelectric tape  300 . In some embodiments, the thermal insulating materials will overlap one another, thereby preventing thermal loss leaking through the spacing between the tapes, for example, when wrapped around a heat pipe. 
     As illustrated in  FIG. 3C , in some cases, a section of the thermoelectric tape  301  can be separated, for example, within the thermoelectric module  313 , such that the section of thermoelectric tape includes thermoelectric modules  311  and  312 . The section of the thermoelectric tape  301  can be used as a power source by outputting power at the buses ( 321 ,  322 ), as illustrated in  FIG. 3D . In some embodiments, the thermoelectric tape  300  includes a plurality of lines of weakness  350 , where each line of weakness is disposed between adjacent two flexible thermoelectric modules of the series of flexible thermoelectric modules  310 . In such embodiments, the line of weakness  350  allows separation of a section of the thermoelectric tape. In some cases, a section of the thermoelectric tape  301  can be designed based on the power requirement. 
       FIG. 3E  shows an example use of the section of thermoelectric tape  301  to wrap around a heat source such as, for example, a steam pipe. In some cases, a thermal insulation stripes  360  is disposed between the thermoelectric modules  310 . In some cases, the thermal insulating stripes  360  are formed from the thermal insulating stripes  341 ,  342  of the thermoelectric tape  300  illustrated in  FIG. 3A . 
       FIGS. 4A-4D  illustrate flow diagrams of example processes of making thermoelectric modules. Some of the steps are optional. Some of the steps may be changed in order.  FIG. 4A  illustrates a flow diagram of one example process of an assembly line making a thermoelectric module. The process can generate a thermoelectric module as illustrated in  FIG. 1D . In such implementations, the thermoelectric module can be thin because of having less layers, such that the module can have higher flexibility and be effective in converting thermal power into electrical power. Each component of the thermoelectric module can use any configurations and embodiments of the corresponding component described herein. First, provide a flexible substrate having a first surface and an opposing second surface (step  410 A). Next, apply a first patterned conductive layer to the first surface of the flexible substrate (step  420 A), where the pattern of first conductive layer forms a first array of connectors and each connector has two ends. In some cases, the first conductive layer can be formed using flexible printed circuit technology. In some cases, the first conductive layer can be formed by sputtering, electrodeposition, or by lamination of a conductive sheet. In some implementations, the pattern of the first conductive layer can be defined photolithographically using a dry film resist, followed by etching. In some other implementatons, the pattern of the first conductive layer can be formed by silk screen printing using a metal-composite ink or paste. In some cases, the pattern of the first conductive layer can be formed by flexographic printing or gravure printing. In some cases, the pattern of the first conductive layer can be formed by ink printing. 
     In some cases, the assembly line generates a number of vias in the flexible substrate (step  430 A), for example, by removing materials from the flexible substrate. In some embodiments, at least some of the vias are positioned corresponding to ends of first array of connectors. Methods for forming vias include laser drilling, die cutting, ion milling, chemical etching, or the like. If the first conductive layer was formed by the lamination of copper sheets, then the lamination adhesive is also removed from the bottom of the vias during the etching step. Further, fill at least some of the vias with a thermoelectric material (step  440 A). In some implementations, the thermoelectric material in the form of a paste can be added to the vias by means of a silk screen deposition process or by a doctor-blade process. In some implementations, the thermoelectric material are synthesized by means of a powder process. In the powder process, constituent materials are mixed together in powder form according to specified ratios, the powders are then pressed together and sintered at high temperature until the powders react to form a desired compound. After sintering, the powders can be ground and mixed with a binder or solvent to form a slurry, ink, or paste. In some implementations, the thermoelectric material can also be placed in the vias by means of a “drop-on-demand” ink jet process. In some implementations, the thermoelectric material can also be added to the vias by means of a dry-powder jet or aerosol process. In some implementations, the thermoelectric material can also be added to the vias by means of flexographic or gravure printing. 
     In some implementations, the thermoelectric material comprises a binder material. Optionally, heat the thermoelectric module to remove the binder material (step  450 A). In some embodiments, the binder material can be, for example, carboxymethyl cellulose, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), or the like. In some cases, if the thermoelectric material added to the vias is in the form ink or paste, the substrate filled with thermoelectric material may be heat-treated so that binders and solvents in the paste are evaporated or pyrolyzed, so that the thermoelectric material is sintered into a solid body with bulk-like thermal and electrical conductivity. Pyrolization of organic binders can occur over temperature ranges between 120° C. and 300° C. Sintering of the thermoelectric materials can occur over temperature ranges between 200° C. and 500° C. For some implementations, it is preferable to heat treat the thermoelectric material in atmospheres of nitrogen or forming gas, to avoid oxidation of the thermoelectric material. 
     Next, apply a second patterned conductive layer to the second surface of the flexible substrate (step  460 A), where the pattern of the second conductive layer forms a second array of connectors and each connector has two ends. In some embodiments, at least some of the ends of the second array of connectors are positioned corresponding to at least some of the vias. The second conductive layer and its pattern can be formed using a process forming the first conductive layer and its pattern. 
     In some implementations, the assembly line applies a thermally conductive adhesive material on the second patterned conductive layer (step  470 A). In some cases, an adhesive layer, optionally with a release liner, can be coated or laminated over a surface of the thermoelectric module. In some embodiments, it is preferable to provide an adhesive layer with a thermally conductive property. This can be accomplished with techniques known in the art such as dispersing gold, silver, or carbon particles, filaments, or flakes within the matrix of the adhesive. The thickness of the thermally conductive adhesive layer is preferably in a range between 10 micrometers and 100 micrometers. The adhesive layer can be coated directly onto the thermoelectric module by means of either an aqueous or solvent-based coating process or by means of a hot-melt extrusion process. In another embodiment, the thermally conductive adhesive layer is prepared as a separate tape article that can be laminated over the top of the thermoelectric module along with a release liner. 
       FIG. 4B  illustrates a flow diagram of another example process of an assembly line making a thermoelectric module. The process can generate a thermoelectric module as illustrated in  FIG. 1E . Each component of the thermoelectric module can use any configurations and embodiments of the corresponding component described herein. Each step can use any embodiments of the corresponding step described in  FIG. 4A . First, provide two flexible substrates, Substrate  1  and Substrate  2 , both with a first and second surfaces (step  410 B). Apply a first patterned conductive layer to the first surface of Substrate  1 , the pattern forming a first array of connectors (step  420 B). Apply a second patterned conductive layer to the first surface of Substrate  2 , the pattern forming a second array of connectors (step  430 B). Generate a number of vias in both substrates, some of the vias are positioned corresponding to ends of a corresponding array of connectors (step  440 B). Fill the vias of both substrates with an electrically conductive material (step  450 B). In some cases, the electrically conductive material can be in the form of solution, ink, paste, or solid. In some cases, the electrically conductive material is filled in the vias by any feasible process, for example, by printing, by vacuum deposition, by silk screen printing, or the like. 
     Optionally, apply an electrically conductive bonding or adhesive material to the second surface of one or both substrates (step  455 B). Place thermoelectric elements on the second surface of Substrate  2  aligning with vias in Substrate  2  (step  460 B). Optionally, fill spaces between the thermoelectric elements with insulator (step  465 B). Align and attach both substrates by facing the second surface toward each other such that vias in the substrates are aligned (step  470 B). In such implementations, the conductive layers are on the outer surfaces of the assembly, and the thermoelectric elements are between the two substrates. Optionally, heat the assembly in order to strengthen the connections of the thermoelectric elements with both substrates and finish lamination (step  475 B). 
       FIG. 4C  illustrates a flow diagram of another example process of an assembly line making a thermoelectric module. The process can generate a thermoelectric module as illustrated in  FIGS. 1A-1C . Each component of the thermoelectric module can use any configurations and embodiments of the corresponding component described herein. Each step can use any embodiments of the corresponding step described in  FIG. 4A . First, provide a flexible substrate having a first and second surfaces (step  410 C). Apply a first patterned conductive layer to the first surface of Substrate  1 , the pattern forming a first array of connectors (step  420 C). Generate a number of vias in both substrates, some of the vias are positioned corresponding to ends of a corresponding array of connectors (step  430 C). Fill the vias of both substrates with an electrically conductive material (step  440 C). In some cases, the electrically conductive material can be in the form of solution, ink, paste, or solid. In some cases, the electrically conductive material is filled in the vias by any feasible process, for example, by printing, by vacuum deposition, by silk screen printing, or the like. 
     Optionally, apply an electrically conductive bonding or adhesive material to the second surface of the substrate (step  445 C). Place thermoelectric elements on the second surface of the substrate aligning with the vias in the substrate (step  450 C). Optionally, fill spaces between the thermoelectric elements with insulator (step  455 C). Apply a second patterned conductive layer to a general surface of the thermoelectric elements, the pattern forming a second array of connectors (step  460 C). Optionally, heat the assembly in order to strengthen the connections of the thermoelectric elements with both substrates and finish lamination (step  465 C). 
       FIG. 4D  illustrates a flow diagram of another example process of an assembly line making a thermoelectric module. The process can generate a thermoelectric module as illustrated in  FIG. 2C . Each component of the thermoelectric module can use any configurations and embodiments of the corresponding component described herein. Each step can use any embodiments of the corresponding step described in  FIG. 4A . First, provide two flexible substrates, Substrate  1  and Substrate  2 , both with a first and second surfaces (step  410 D). Apply a first patterned conductive layer to the first surface of Substrate  1 , the pattern forming a first array of connectors (step  420 D). Apply a second patterned conductive layer to the first surface of Substrate  2 , the pattern forming a second array of connectors (step  430 D). Generate a number of vias in both substrates, some of the vias are positioned corresponding to ends of a corresponding array of connectors (step  440 D). 
     Fill some of the vias of both substrates with a different type of thermoelectric material (step  450 D). In some cases, every other via is filled with the thermoelectric material. Fill the rest of the vias of both substrates with an electrically conductive material (step  460 D). For example, half of the vias of Substrate  1  are filled with p-type thermoelectric material and the rest of vias of Substrate  1  are filled with the conductive material; and half of the vias of Substrate  2  are filled with n-type thermoelectric material and the rest of vias of Substrate  2  are filled with the conductive material. In some cases, the electrically conductive material can be in the form of solution, ink, paste, or solid. In some cases, the electrically conductive material is filled in the vias by any feasible process, for example, by printing, by vacuum deposition, by silk screen printing, or the like. 
     Optionally, apply an electrically conductive bonding or adhesive material to the second surface of one or both substrates (step  465 D). Place thermoelectric elements on the second surface of Substrate  2  aligning with vias in Substrate  2  (step  460 D). Optionally, fill spaces between the thermoelectric elements with insulator (step  465 D). Align and attach both substrates by facing the second surface toward each other such that vias filled with a thermoelectric material in Substrate  1  are aligned with vias filled with the electrically conductive material in Substrate  2  (step  470 D). Similarly, vias filled with the electrically conductive material in Substrate  1  are aligned with vias filled with a thermoelectric material in Substrate  2 . In such implementations, the conductive layers are on the outer surfaces of the assembly. Optionally, heat the attached substrates in order to strengthen the connections between the filled vias of both substrates and finish lamination (step  475 D). 
     EXAMPLES 
     Example 1 
     Thermoelectric Module with Metal filled Vias 
     The thermoelectric modules as represented in  FIGS. 1C  were assembled. As illustrated in  FIG. 1C , 1.0 mm vias  115  were punctured into a 0.1 mm thick 200×50 mm flexible polyimide substrate  110  obtained from 3M Company of St. Paul, Minn. every 2.5 mm. The vias were made by chemically milling through the substrate  110 . The vias  115  were filled with copper deposited into the vias  115  by chemical vapor deposition (CVD) and electrochemical deposition. A 0.2 mm layer of Anisotropic Conductive Adhesive 7379 obtained from 3M Company of St. Paul, Minn. was deposited on top of the copper filled vias  115  as the bonding component  150 . Alternating p-type Sb 2 Te 3  and n-type Bi 2 Te 3  0.5 mm-thick thermoelectric elements  122 ,  124  obtained from Thermonamic, Inc. in Jiangxi China were deposited onto bonding component  150  covering the vias  115  by element transfer. 0.5-thick mm polyurethane insulators  160  were positioned between the thermoelectric elements  122 ,  124  by drop-on-demand printing. 4.3×1.8×0.1 mm copper connectors  130  were deposited by electrochemical deposition on the second substrate  112 . 4.3×1.8×0.1 mm silver connectors  140  were deposited through silk screen printing on the first substrate surface  111  of the flexible polyimide substrate to connect the p-type and n-type thermoelectric elements  122 ,  124 . 
     Example 2 
     Thermoelectric Module with Thermoelectric Element filled Vias 
     The thermoelectric modules as represented in  FIGS. 1D  were assembled. As illustrated in 
       FIG. 1D , 1.0 mm vias  115  were punctured into a 0.1 mm thick 200×50 mm flexible polyimide substrate  110  obtained from 3M Company of St. Paul, Minn, every 2.5 mm. The vias were made by chemically milling through the substrate  110 . The vias  115  were filled with alternating p-type Sb 2 Te 3  and n-type Bi 2 Te 3  thermoelectric elements  122 ,  124  ink-formulated by the powders obtained from Super Conductor Materials, Inc. of Tallman, N.Y. that were deposited into the vias  115  by silk screen printing. 4.3×1.8×0.1 mm copper connectors  130  were deposited by electrochemical deposition on the second substrate surface  112 . 4.3×1.8×0.1 mm silver connectors  140  were deposited through silk screen printing on the first substrate surface  111  of the flexible polyimide substrate to connect the p-type and n-type thermoelectric elements  122 ,  124 . 
     Example 3 
     Thermoelectric Tape 
     A thermoelectric module constructed in a tape form as represented in  FIG. 3A  was assembled. A 0.1 mm-thick flexible polyimide substrate was manufactured in 3M Company of St. Paul, Minn. to construct a 30 meter-long tape incorporating multiple thermoelectric modules  310 . A polyimide substrate having 30 μm-thick copper conductive buses ( 321 ,  322 ) connected longitudinally arranged thermoelectric modules  310  electrically in parallel. The thermoelectric module assembled in Example 1 was used to construct the tape&#39;s single module ( 311 ). A silver particle loaded Conductive Adhesive Transfer Tape 9704 from 3M Company of St. Paul, Minn. was used for the thermally conductive adhesive layer  330 . 
     Exemplary Embodiments 
     Item A1. A flexible thermoelectric module, comprising: 
     a flexible substrate comprising a plurality of vias filled with an electrically conductive material, the flexible substrate having a first substrate surface and a second substrate surface opposing to the first substrate surface; 
     a plurality of p-type thermoelectric elements and a plurality of n-type thermoelectric elements disposed on the first surface of the flexible substrate, at least part of the plurality of p-type and n-type thermoelectric elements electrically connected to the plurality of vias, wherein a p-type thermoelectric element is adjacent to a n-type thermoelectric element; 
     a first set of connectors disposed on the second surface of the flexible substrate, wherein each of the first set of connectors electrically connects a pair of adjacent vias; and 
     a second set of connectors printed directly on the plurality of p-type and n-type thermoelectric elements, wherein each of the second set of connectors electrically connected to a pair of adjacent p-type and n-type thermoelectric elements. 
     Item A2. The flexible thermoelectric module of Item A1, further comprising: 
     an insulator disposed among the plurality of p-type and n-type thermoelectric elements. 
     Item A3. The flexible thermoelectric module of Item A1 or A2, further comprising: 
     a bonding component disposed between one of the plurality of p-type and n-type thermoelectric elements and a via. 
     Item A4. The flexible thermoelectric module of any one of Item A1-A3, wherein the thickness of the thermoelectric module is no greater than 1 mm. 
     Item A5. The flexible thermoelectric module of any one of Item A1-A4, wherein the thickness of the thermoelectric module is no greater than 0.3 mm. 
     Item A6. The flexible thermoelectric module of any one of Item A1-A5, further comprising: an abrasion protective layer disposed adjacent to one of the first and second sets of connectors. 
     Item A7. The flexible thermoelectric module of any one of Item A1-A6, further comprising: a release liner disposed adjacent to the abrasion protective layer. 
     Item A8. The flexible thermoelectric module of any one of Item A1-A7, further comprising: an adhesive layer disposed adjacent to one of the first and second sets of connectors. 
     Item A9. The flexible thermoelectric module of Item A8, further comprising: 
     a release liner disposed adjacent to the adhesive layer. 
     Item A10. The flexible thermoelectric module of any one of Item A1-A9, wherein a unit area thermal resistance of the flexible thermoelectric module is no greater than 1.0 K-cm 2 /W. 
     Item A11. The flexible thermoelectric module of any one of Item A1-A10, wherein the thermoelectric elements comprise at least one of a chalcogenide, an organic polymer, an organic composite, and a porous silicon. 
     Item A12. The flexible thermoelectric module of any one of Item A1-A11, wherein the flexible substrate comprises a polyimide, polyethylene, polypropylene, polymethymethacrylate, polyurethane, polyaramide, liquid crystalline polymers (LCP), polyolefins, fluoropolymer based films, silicone, cellulose, or a combination thereof. 
     Item A13. The flexible thermoelectric module of any one of Item A1-A12, wherein heat propagates generally perpendicular to the flexible substrate when the flexible thermoelectric module is in use. 
     Item A14. The flexible thermoelectric module of Item A13, wherein a majority of heat propagates through the plurality of vias. 
     Item A15. The flexible thermoelectric module of any one of Item A1-A14, wherein when the thermoelectric module is used with a predefined thermal source, the thermoelectric module has a thermal resistance having an absolute difference less than 10% from a thermal resistance of the predefined thermal source. 
     Item A16. The flexible thermoelectric module of any one of Item A1-A15, wherein the electrically conductive material comprises no less than 50% of copper. 
     Item B1. A flexible thermoelectric module, comprising: 
     a first flexible substrate comprising a first set of vias, the first flexible substrate comprising a first surface and a second surface opposing to the first surface, 
     a first set of thermoelectric elements disposed in at least a part of the first set of vias, 
     a first set of connectors disposed on the first surface of the first flexible substrate, wherein each of the first set of connectors electrically connects to a pair of adjacent vias of the first set of vias; and 
     a second flexible substrate comprising a second set of vias, 
     a plurality of conductive bonding components sandwiched between the first flexible substrate and the second substrate, each conductive bonding component aligned to a first via in the first set of vias and a second via in the second set of vias, 
     a second set of thermoelectric elements disposed in at least a part of the second set of vias, 
     a second set of connectors disposed on a surface of the second flexible substrate away from the first flexible substrate, 
     wherein each of the second set of connectors electrically connects to a pair of adjacent vias of the second set of vias. 
     Item B2. The flexible thermoelectric module of Item B1, wherein a different one of p-type and n-type thermoelectric elements are disposed in two adjacent vias of the first set of vias. 
     Item B3. The flexible thermoelectric module of Item B2, wherein a different one of p-type and n-type thermoelectric elements are disposed in two adjacent vias of the second set of vias. 
     Item B4. The flexible thermoelectric module of any one of Item B1-B3, wherein the first flexible substrate is attached to the second flexible substrate, such that a via in the first flexible substrate is generally aligned with a via in the second flexible substrate having a same type of thermoelectric element. 
     Item B5. The flexible thermoelectric module of any one of Item B1-B4, wherein the first set of thermoelectric elements are of a first type of thermoelectric elements. 
     Item B6. The flexible thermoelectric module of Item B5, wherein the second set of thermoelectric elements are of a second type of thermoelectric elements that is different from the first type of thermoelectric elements. 
     Item B7. The flexible thermoelectric module of Item B6, wherein a thermoelectric element of the first type and a first conductive material are disposed in two adjacent vias of the first set of vias. 
     Item B8. The flexible thermoelectric module of Item B7, wherein a thermoelectric element of the second type and a second conductive material are disposed in two adjacent vias of the second set of vias. 
     Item B9. The flexible thermoelectric module of Item B8, wherein the first flexible substrate is attached to the second flexible substrate, such that a via having the thermoelectric element of the first type in the first flexible substrate is generally aligned with a via having the second conductive material in the second flexible substrate. 
     Item B10. The flexible thermoelectric module of Item B9, wherein a via having the first conductive material is generally aligned with a via having the thermoelectric element of the second type in the second flexible substrate. 
     Item B11. The flexible thermoelectric module of Item B8, wherein the first conductive material is the same as the second conductive material. 
     Item B12. The flexible thermoelectric module of any one of Item B1-B11, further comprising: an insulator disposed among the plurality of p-type and n-type thermoelectric elements. 
     Item B13. The flexible thermoelectric module of any one of Item B1-B12, further comprising: a bonding component disposed between one of the plurality of p-type and n-type thermoelectric elements and a via. 
     Item B14. The flexible thermoelectric module of any one of Item B1-B13, wherein the thickness of the thermoelectric module is no greater than 1 mm. 
     Item B15. The flexible thermoelectric module of any one of Item B1-B14, wherein the thickness of the thermoelectric module is no greater than 0.3 mm. 
     Item B16. The flexible thermoelectric module of any one of Item B1-B15, further comprising: a abrasion protective layer disposed adjacent to one of the first and second sets of connectors. 
     Item B17. The flexible thermoelectric module of any one of Item B1-B16, further comprising: a release liner disposed adjacent to the abrasion protective layer. 
     Item B18. The flexible thermoelectric module of any one of Item B1-B17, further comprising: an adhesive layer disposed adjacent to one of the first and second sets of connectors. 
     Item B19. The flexible thermoelectric module of Item B18, further comprising: 
     a release liner disposed adjacent to the adhesive layer. 
     Item B20. The flexible thermoelectric module of any one of Item B1-B19, wherein a unit area thermal resistance of the flexible thermoelectric module is no greater than 1.0 K-cm 2 /W. 
     Item B21. The flexible thermoelectric module of any one of Item B1-B20, wherein the thermoelectric elements comprise at least one of a chalcogenide, an organic polymer, an organic composite, and a porous silicon. 
     Item B22. The flexible thermoelectric module of any one of Item B1-B21, wherein the flexible substrate comprises a polyimide, polyethylene, polypropylene, polymethymethacrylate, polyurethane, polyaramide, silicone, cellulose, or a combination thereof. 
     Item B23. The flexible thermoelectric module of any one of Item B1-B22, wherein heat propagates generally perpendicular to the flexible substrate when the flexible thermoelectric module is in use. 
     Item B24. The flexible thermoelectric module of Item B23, wherein a majority of heat propagates through the first set of vias and the second set of vias. 
     Item B25. The flexible thermoelectric module of any one of Item B1-B24, wherein when the thermoelectric module is used with a predefined thermal source, the thermoelectric module has a thermal resistance having an absolute difference less than 10% from a thermal resistance of the predefined thermal source. 
     Item C1. A flexible thermoelectric module made by a process comprising the steps of: 
     providing a flexible substrate having a first surface and an opposing second surface; 
     applying a first patterned conductive layer to the first surface of the flexible substrate, wherein the pattern of first conductive layer forms a first array of connectors and each connector has two ends; 
     generating a plurality of vias on the flexible substrate by removing materials from flexible substrate, wherein at least some of the vias are positioned corresponding to ends of first array of connectors; 
     filling at least some of the vias with a thermoelectric material; 
     applying a second patterned conductive layer to the second surface of the flexible substrate, 
     wherein the pattern of the second conductive layer forms a second array of connectors and each connector has two ends, and 
     wherein at least some of the ends of the second array of connectors are positioned corresponding to at least some of the vias. 
     Item C2. The flexible thermoelectric module of Item C1, wherein the thermoelectric material comprises a binder material. 
     Item C3. The flexible thermoelectric module of Item C2, wherein the process further comprises the step of: 
     heating the thermoelectric module to remove the binder material. 
     Item C4. The flexible thermoelectric module of any one of Item C1-C3, wherein the process further comprises the step of: applying a thermally conductive adhesive material on the second patterned conductive layer. 
     Item C5. The flexible thermoelectric module of any one of Item C1-C4, wherein the step of applying a first patterned conductor layer precedes the step of filling at least one of vias with a thermoelectric material. 
     Item C6. The flexible thermoelectric module of any one of Item C1-05, wherein the thickness of the thermoelectric module is no greater than 1 mm. 
     Item C7. The flexible thermoelectric module of any one of Item C1-C6, wherein the thickness of the thermoelectric module is no greater than 0.3 mm. 
     Item C8. The flexible thermoelectric module of any one of Item C1-C7, wherein the process further comprises the step of: disposing an abrasion protective layer adjacent to one of the first and second conductive layer. 
     Item C9. The flexible thermoelectric module of Item C8, wherein the process further comprises the step of: 
     disposing a release liner adjacent to the abrasion protective layer. 
     Item C10. The flexible thermoelectric module of any one of Item C1-C9, wherein the process further comprises the step of: 
     disposing an adhesive layer adjacent to at least one of the first and second conductive layers. 
     Item C11. The flexible thermoelectric module of Item C10, wherein the process further comprises the step of: 
     disposing a release liner adjacent to the adhesive layer. 
     Item C12. The flexible thermoelectric module of any one of Item C1-C11, wherein a unit area thermal resistance of the flexible thermoelectric module is no greater than 1.0 K-cm 2 /W. 
     Item C13. The flexible thermoelectric module of any one of Item C1-C12, wherein the thermoelectric material comprise at least one of a chalcogenide, an organic polymer, an organic composite, and a porous silicon. 
     Item C14. The flexible thermoelectric module of any one of Item C1-C13, wherein the flexible substrate comprises a polyimide, polyethylene, polypropylene, polymethymethacrylate, polyurethane, polyaramide, silicone, cellulose, or a combination thereof. 
     Item C15. The flexible thermoelectric module of any one of Item C1-C14, wherein when the thermoelectric module is used with a predefined thermal source, the thermoelectric module has a thermal resistance having an absolute difference less than 10% from a thermal resistance of the predefined thermal source. 
     Item D1. A flexible thermoelectric module made by a process comprising the steps of: 
     providing a flexible substrate having a first surface and an opposing second surface; 
     applying a first patterned conductive layer to the first surface of the flexible substrate, wherein the pattern of the first conductive layer forms a first array of connectors and each connector has two ends; 
     generating a plurality of vias on the flexible substrate by removing materials from flexible substrate, wherein at least some of the vias are positioned corresponding to ends of first array of connectors; 
     filling at least some of the vias with an electrically conductive material; 
     placing thermoelectric elements on the second surface of the substrate aligning with the vias; 
     printing a second patterned conductive layer on top of the thermoelectric elements, 
     wherein the pattern of the second conductive layer forms a second array of connectors and each connector has two ends, and 
     wherein at least some of the ends of the second array of connectors are positioned corresponding to at least some of the thermoelectric elements. 
     Item D2. The flexible thermoelectric module of Item D1, wherein at least one of the thermoelectric element comprises a binder material. 
     Item D3. The flexible thermoelectric module of Item D2, wherein the process further comprises the step of: 
     heating the thermoelectric module to remove the binder material. 
     Item D4. The flexible thermoelectric module of any one of Item D1-D3, wherein the process further comprises the step of: applying a thermally conductive adhesive material on the first or second conductive layer. 
     Item D5. The flexible thermoelectric module of any one of Item D1-D4, wherein the process further comprises the step of: disposing an insulator among the thermoelectric elements. 
     Item D6. The flexible thermoelectric module of any one of Item D1-D5, wherein the process further comprises the step of: disposing a bonding component between one of the thermoelectric elements and a via. 
     Item D7. The flexible thermoelectric module of any one of Item D1-D6, wherein the thickness of the thermoelectric module is no greater than 1 mm. 
     Item D8. The flexible thermoelectric module of any one of Item D1-D7, wherein the thickness of the thermoelectric module is no greater than 0.3 mm. 
     Item D9. The flexible thermoelectric module of any one of Item Dl-D8, wherein the process further comprises the step of: disposing an abrasion protective layer adjacent to at least one of the first and second conductive layers. 
     Item D10. The flexible thermoelectric module of Item D9, wherein the process further comprises the step of: disposing a release liner adjacent to the abrasion protective layer. 
     Item D11. The flexible thermoelectric module of any one of Item D1, wherein the process further comprises the step of: disposing an adhesive layer adjacent to at least one of the first and second conductive layers. 
     Item D12. The flexible thermoelectric module of Item D11, wherein the process further comprises the step of: disposing a release liner adjacent to the adhesive layer. 
     Item D13. The flexible thermoelectric module of any one of Item D1-D12, wherein a unit area thermal resistance of the flexible thermoelectric module is no greater than 1.0 K-cm 2 /W. 
     Item D14. The flexible thermoelectric module of any one of Item D1-D13, wherein the thermoelectric elements comprise at least one of a chalcogenide, an organic polymer, an organic composite, and a porous silicon. 
     Item D15. The flexible thermoelectric module of any one of Item D1-D14, wherein the flexible substrate comprises a polyimide, polyethylene, polypropylene, polymethymethacrylate, polyurethane, polyaramide, silicone, cellulose, or a combination thereof. 
     Item D16. The flexible thermoelectric module of any one of Item D1-D15, wherein when the thermoelectric module is used with a predefined thermal source, the thermoelectric module has a thermal resistance having an absolute difference less than 10% from a thermal resistance of the predefined thermal source. 
     Item E1. A thermoelectric tape, comprising: 
     a flexible substrate having a plurality of vias; 
     a series of flexible thermoelectric modules integrated with the flexible substrate and connected in parallel, each flexible thermoelectric module comprising:
         a plurality of p-type thermoelectric elements,   a plurality of n-type thermoelectric elements, wherein at least some of the plurality of p-type thermoelectric element are connected to n-type thermoelectric elements;       

     two conductive buses running longitudinally along the thermoelectric tape, wherein the series of flexible thermoelectric modules are electrically connected to the conductive buses; and 
     a thermally conductive adhesive layer disposed on a surface of the flexible substrate. 
     Item E2. The thermoelectric tape of Item E1, further comprising: 
     a stripe of thermal insulating material disposed longitudinally along the thermoelectric tape. 
     Item E3. The thermoelectric tape of Item E1 or E2, further comprising: 
     two stripes of thermal insulating material disposed longitudinally along the thermoelectric tape, each of the two stripes of thermal insulating material disposed at an edge of the thermoelectric tape. 
     Item E4. The thermoelectric tape of any one of Item E1-E3, wherein the thermoelectric tape is in the form of a roll. 
     Item E5. The thermoelectric tape of any one of Item E1-E4, further comprising: a plurality of lines of weakness, each line of weakness disposed between adjacent two flexible thermoelectric modules of the series of flexible thermoelectric modules. 
     Item E6. The thermoelectric tape of any one of Item E1-E5, wherein each thermoelectric module further comprises: an insulator disposed among the plurality of p-type and n-type thermoelectric elements. 
     Item E7. The thermoelectric tape of any one of Item E1-E6, wherein each thermoelectric module further comprises: a bonding component disposed between one of the plurality of p-type and n-type thermoelectric elements and a via. 
     Item E8. The thermoelectric tape of any one of Item E1-D7, wherein the thickness the thermoelectric tape is no greater than 1 mm. 
     Item E9. The thermoelectric tape of any one of Item E1-E8, wherein the thickness of the thermoelectric tape is no greater than 0.3 mm. 
     Item E10. The thermoelectric tape of any one of Item E1-E9, further comprising: a first conductive layer disposed on a first side of the flexible substrate, wherein the first conductive layer has a pattern forming a first set of connectors. 
     Item E11. The thermoelectric tape of Item E10, further comprising: a second conductive layer disposed on a second side of the flexible substrate opposed to the first side, wherein the second conductive layer has a pattern forming a second set of connectors. 
     Item E12. The thermoelectric tape of Item E11, wherein each of the first set and the second set of connectors electrically connect a pair of thermoelectric elements. 
     Item E13. The thermoelectric tape of Item E12, wherein a first connector in the first set of connectors electrically connect a first pair of thermoelectric elements and a second connector in the second set of connectors electrically connect a second pair of thermoelectric elements, and wherein the first pair of thermoelectric elements and the second pair of thermoelectric elements have one and only one thermoelectric element in common. 
     Item E14. The thermoelectric tape of Item E11, further comprising: a abrasion protective layer disposed adjacent to at least one of the first and second conductive layers. 
     Item E15. The thermoelectric tape of Item E14, further comprising: a release liner disposed adjacent to the abrasion protective layer. 
     Item E16. The thermoelectric tape of Item E11, further comprising: an adhesive layer disposed adjacent to at least one of the first and second conductive layers. 
     Item E17. The thermoelectric tape of Item E16, further comprising: a release liner disposed adjacent to the adhesive layer. 
     Item E18. The thermoelectric tape of any one of Item E1-E17, wherein a unit area thermal resistance of the thermoelectric tape is no greater than 1.0 K-cm 2 /W. 
     Item E19. The thermoelectric tape of any one of Item E1-E18, wherein the thermoelectric elements comprise at least one of a chalcogenide, an organic polymer, an organic composite, and a porous silicon. 
     Item E20. The thermoelectric tape of any one of Item E1-E19, wherein the flexible substrate comprises a polyimide, polyethylene, polypropylene, polymethymethacrylate, polyurethane, polyaramide, silicone, cellulose, or a combination thereof. 
     Item E21. The thermoelectric tape of any one of Item E1-E20, wherein when a portion of the thermoelectric tape is used with a predefined thermal source, the portion of the thermoelectric tape has a thermal resistance having an absolute difference less than 10% from a thermal resistance of the predefined thermal source. 
     Item E22. The thermoelectric tape of any one of Item E1-E21, wherein at least some of the plurality of vias are filled with an electrically conductive material. 
     Item E23. The thermoelectric tape of any one of Item E1-E22, wherein the electrically conductive material comprises no less than 50% of copper. 
     Item E24. The thermoelectric tape of any one of Item E1-E23, wherein at least some of the plurality of vias are filled with p-type thermoelectric elements. 
     Item E25. The thermoelectric tape of any one of Item E1-E24, wherein at least some of the plurality of vias are filled with n-type thermoelectric elements. 
     The present invention should not be considered limited to the particular examples and embodiments described above, as such embodiments are described in detail to facilitate explanation of various aspects of the invention. Rather the present invention should be understood to cover all aspects of the invention, including various modifications, equivalent processes, and alternative devices falling within the spirit and scope of the invention as defined by the appended claims and their equivalents.