TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The thermoelectric power source further comprises greater than or equal to 50 (preferably greater than or equal to 1,000) thermocouples. The p-type thermoelements have different widths as compared to the n-type thermoelements. Two or more p-type thermoelements are positioned and electrically connected in parallel with one another. The parallel positioned p-type thermoelements are electrically connected in series to the n-type thermoelements. Two or more n-type thermoelements are positioned and electrically connected in parallel with one another. The parallel positioned n-type thermoelements are electrically connected in series to the p-type thermoelements. The thermocouples are electrically connected in series on the upper surface of the substrate. The substrate is in a coil configuration. The thermoelectric power source produces power at temperature differences of less than or equal to 20degreesC. The p-type or n-type thermoelement is a superlattice. The superlattice comprises alternating bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) layers with thicknesses of 50-150 Angstrom . The n-type thermoelements are free of selenium.Preferred Method: The method further comprises winding the flexible substrate into the coil configuration and activating the thermoelectric power source by a temperature gradient of less than or equal to 20degreesC. A radio frequency (RF) power of 30 watts is supplied to the Sb2Te3 target and an RF power of 10 watts is supplied to the Bi2Te3 target to sputter deposit the thin film of the p-type thermoelectric material. An RF power of 30 watts is supplied to the Sb2Te3 target and an RF power of 20 watts is supplied to the Bi2Te3 target to sputter deposit the thin film of the n-type thermoelectric material. A sputtering gas pressure is maintained at 3 milli torr during the sputter deposition of the thin film of the n-type thermoelectric material.Preferred Properties: The p-type or n-type thermoelements have L/A ratios greater than 20, preferably greater than 100 cm-1. The thermoelectric power source has a power output of greater than or equal to 1 muW with a voltage of greater than or equal to 0.25 volt or a power output of 1 W with a voltage of greater than or equal to 1 volt, a volume of 10 cm3, and voltages of greater than 1 volt. The p-type or n-type thermoelements are greater than or equal to 1 mm in length, greater than or equal to 0.1 mm in width, and greater than or equal to 20 Angstrom in thickness.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The p-type or n-type thermoelements comprise BiaTeb. They are BixTey, SbxTey or BixSey alloys. Targets used for sputter depositing the thin film of the n-type or p-type thermoelectric material onto the flexible substrate comprise Sb2Te3 and Bi2Te3.a, x = 2;andb, y = 3.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The p-type or n-type thermoelements comprise BiaTeb. They are BixTey, SbxTey or BixSey alloys. Targets used for sputter depositing the thin film of the n-type or p-type thermoelectric material onto the flexible substrate comprise Sb2Te3 and Bi2Te3.a, x = 2;andb, y = 3.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The substrate is a polyimide.