Low power thermoelectric generator

Abstract

Disclosed is a foil segment for a thermoelectric generator comprising a top plate disposed in spaced relation above a bottom plate. An array of the foil segments is perpendicularly disposed in side-by-side arrangement between and in thermal contact with the bottom and top plates. Each foil segment comprises a substrate having a thickness of about 7.5-50 microns, opposing front and back substrate surfaces and a series of spaced alternating n-type and p-type thermoelectric legs disposed in parallel arrangement on the front substrate surface. Each of the n-type and p-type legs is formed of a bismuth telluride-based thermoelectric material having a thickness of about 5-100 microns, a width of about 10-100 microns and a length of about 100-500 microns. The alternating n-type and p-type thermoelectric legs are electrically connected in series and thermally connected in parallel such that a temperature differential between the bottom and top plates results in the generation of power.

1 . A foil segment for a thermoelectric generator, the foil segment comprising: 
 a substrate having opposing front and back substrate surfaces; and    a series of elongate alternating n-type and p-type thermoelectric legs disposed in spaced parallel arrangement on the front substrate surface, each of the n-type and p-type legs being formed of a thermoelectric material having a thickness in the range of from about 5 microns to about 100 microns, each n-type and p-type thermoelectric leg having a width and a length, the width being in the range of from about 10 microns to about 100 microns, the length being in the range of from about 100 microns to about 500 microns;    wherein each one of the p-type thermoelectric legs is electrically connected to an adjacent one of the n-type thermoelectric legs at opposite ends of the p-type thermoelectric legs such that the series of n-type and p-type thermoelectric legs are electrically connected in series and thermally connected in parallel.    
   
   
       2 . The foil segment of  claim 1  wherein the substrate has a thickness in the range of from about 7.5 microns to about 50 microns.  
   
   
       3 . The foil segment of  claim 1  wherein the substrate has a thickness of about 25 microns.  
   
   
       4 . The foil segment of  claim 1  wherein the thickness of the thermoelectric material is about 7 microns.  
   
   
       5 . The foil segment of  claim 1  wherein the thermoelectric material for the p-type thermoelectric legs is a semiconductor compound having the following formula:  
       (Bi 0.15 Sb 0.85 ) 2 Te 3  plus about 10 at. % Te excess to about 30 at. % Te excess.  
   
   
       6 . The foil segment of  claim 5  wherein the semiconductor compound has about 18 at. % excess.  
   
   
       7 . The foil segment of  claim 5  wherein each one of the p-type thermoelectric legs has a width of about 40 microns.  
   
   
       8 . The foil segment of  claim 1  wherein each one of the n-type thermoelectric legs has a width of about 60 microns.  
   
   
       9 . The foil segment of  claim 1  wherein the length of the n-type and p-type thermoelectric legs is about 500 microns.  
   
   
       10 . The foil segment of  claim 1  wherein the semiconductor compound is deposited on the substrate by sputtering.  
   
   
       11 . The foil segment of  claim 10  wherein the sputtering deposition rate is in the range of from about 2 nanometers per second to about 10 nanometers per second.  
   
   
       12 . The foil segment of  claim 11  wherein the sputtering deposition rate is about 2.7 nanometers per second.  
   
   
       13 . An array of foil segments for a thermoelectric generator, each one of the foil segments being configured as defined in  claim 1  wherein: 
 each one of the p-type thermoelectric legs and an adjacent one of the n-type thermoelectric legs collectively defines a thermocouple; and    the array of foil segments includes a total of from about 1000 to about 20,000 thermocouples substantially evenly distributed upon the array of foil segments.    
   
   
       14 . A foil segment for a thermoelectric generator, the foil segment including a plurality of n-type and p-type thermoelectric legs, each one of the p-type thermoelectric legs being formed of a semiconductor compound having the following formula:  
       (Bi 0.15 Sb 0.85 ) 2 Te 3  plus about 10 at. % Te excess to about 30 at. % Te excess.  
   
   
       15 . The foil segment of  claim 14  wherein the semiconductor compound has about 18 at. % excess.  
   
   
       16 . A foil segment for a thermoelectric generator, the foil segment comprising: 
 a substrate having a thickness in the range of from about 7.5 microns to about 50 microns and including opposing front and back substrate surfaces, the substrate formed of an electrically insulating material having a low thermal conductivity; and    a series of spaced alternating n-type and p-type thermoelectric legs disposed in parallel arrangement on each one of the front substrate surfaces, each of the n-type and p-type legs being formed of a thermoelectric material and having a thickness in the range of from about 5 microns to about 100 microns, each n-type and p-type thermoelectric leg having a width and a length, the width being in the range of from about 10 microns to about 100 microns and the length being in the range of from about 100 microns to about 500 microns;    wherein each one of the p-type thermoelectric legs is electrically connected to adjacent n-type thermoelectric legs at opposite ends of the p-type thermoelectric legs such that the series of n-type and p-type thermoelectric legs are electrically connected in series and thermally connected in parallel.    
   
   
       17 . The foil segment of  claim 16  wherein each one of the p-type thermoelectric legs is formed of a semiconductor compound having the following formula:  
       (Bi 0.15 Sb 0.85 ) 2 Te 3  plus about 18 at. % excess.