Porous organic filler for high efficiency of flexible thermoelectric generator

Flexible thermoelectric modules (TEMs) are often built with a polymer filler as structural support. However, the filler may serve as a thermal bypass, leading to reduced temperature difference across a TEM and degradation of the output. Herein, we present flexible TEMs made of porous PDMS fillers and Bi2Te3-based thermoelectric legs. The heat conduction through the filler is suppressed by leveraging the low thermal conductivity of porous PDMS (0.08 W/m∙K), leading to an increase in the temperature difference across the TEMs. The porous PDMS TEM exhibits 23% enhanced power density and a figure of merit (ZT) of 0.75 around the room temperature. Lastly, the efficacy of the porous PDMS TEM is demonstrated by testing the TEMs with body heat. Our approach would offer a promising insight into the flexible TEM designs. [Display omitted] •Porous organic filler (0.08 W/m K) increased the temperature difference across thermoelectric legs.•Filler thickness determined a performance of a thermoelectric module.•The device with a thin filler was able to withstand a bending radius of 15 mm.•Internal ΔT reached 91.5% of external ΔT thanks to the novel structure of our approach.•A reduced conduction via the filler lead to ZT of 0.75.