A method includes forming a thin-film based thermoelectric module by sputter depositing pairs of N-type and P-type thermoelectric legs electrically in contact with one another on corresponding electrically conductive pads on a flexible substrate having a dimensional thickness less than or equal to 25 μm, with the legs having extended areas compared to the corresponding electrically conductive pads, and rendering the formed thin-film based thermoelectric module flexible and less than or equal to 100 μm in dimensional thickness based on choices of fabrication processes. The method also includes encapsulating the formed thin-film based thermoelectric module with an elastomer to render the flexibility thereto. The elastomer encapsulation has a dimensional thickness less than or equal to 15 μm, and the flexibility enables an array of thin-film based thermoelectric modules to be completely wrappable and bendable around a system element from which the array is configured to derive thermoelectric power.