Fabrication and Evaluation of Highly Flexible Thermoelectric Cooling Devices

Wearable and flexible thermoelectric devices (TED) have attracted significant amount of attentions over the past decade as active cooling devices to lower the human skin temperature for broad civilian and military applications. However, the rigidity of the commercially available ceramic packaged TEDs has limited their widespread applications. Recently, we developed highly flexible TEDs utilizing the bismuth telluride-based TE pillars, thin copper electrodes, and insulating Ecoflex rubber. Several TEDs have been fabricated with Ecoflex films of different thicknesses. Those TEDs, when paired with the efficient and flexible heatsinks fabricated utilizing Ecoflex, flexible Cu foam, thermally conductive aluminum nitride (AlN) and a phase-change material (PCM), were capable of lowering the skin temperature from 36 °C to a comfort point at 32 °C for at least 12 min when the surrounding temperature was set at 37 °C. Characterization and evaluation of the fabricated TEDs for active cooling along with a number of heatsinks were performed, and their flexibility and durability were examined. The detailed fabrication and analysis of the devices will be discussed.