Optimization of a wearable thermoelectric generator encapsulated in polydimethylsiloxane (PDMS) : a numerical modelling

To mitigate climate change attributed to the electricity generation, there have been tremendous efforts in replacing fossil fuels with renewable energies in the electricity sector. For this purpose, wearable thermoelectric generators (WTEGs) are the most promising direct and green power generation technique for portable electronics. In spite of extensive research, there is a trade-off relationship between the flexibility of WTEGs and their power output. Thus, this research aims to improve the performance of a flexible WTEG through differing thermal conditions around the hot and cold junctions. Accordingly, the PDMS substrate of a flexible WTEG is segmented into two layers, whereas each layer is individually filled with different fillers. Accordingly, three different patterns are proposed for the segmentation. Then, using COMSOL Multiphysics software, the output voltage and power of the specified patterns are analyzed and compared with those of an original flexible WTEG. Results concluded that releasing the thermoelectric legs from PDMS coating can remarkably improve the output voltage as well as the power generation. In addition, with regard to the segmentation pattern, adding fillers to the PDMS layers has a twofold effect on the voltage and power generation. Precisely, the thickness of each segment should be taken into consideration for selecting an appropriate filler. This work paves the way for enhancing the performance of flexible WTEGs, which ultimately leads to low carbon and energy-efficient electricity generation.