Paper-based thermoelectric generators for viable waste heat harvesting

Abstract There is currently an ongoing surge of effort toward sustainable, self-powered, scalable clean energy sources for next generation wireless electronics, IoT sensors and wearable microelectronics. Globally, almost two-thirds of the converted energy is lost as heat energy during the processes of power generation and energy conversion from fossil fuels and other traditional energy sources. Thermoelectric (TE) generators (TEG) add a robust solution toward efficiently harvesting low gradient waste heat energy into extractable micropower, offering scalable and viable choices to generate electricity ranging from excess heat generated in solar panels, automobile exhaust and factory heat outlets to day-to-day human activities, domestic electrical equipment and electronics. Paper-based TEGs (PTEGs) have become an area of immense research activity in the last few years, mainly because of the environmentally friendly, flexible, economic, and easy industry translatable nature of paper/cellulose. Even though PTEG’s output performance still lags behind the performance of other flexible TEGs, rapid research directions toward materializing PTEG design, and including more varieties of TE materials and methods are having a large impact upon further PTEG performance optimization. This review gives a concise overview of recent results, discussing the progress, advantages and potential barriers in PTEG research with a view to predicting future strategies and goals to increase their functionality in the thermal energy harvesting market.