Thermoelectric generators (TEGs) are solid-state heat engines consisting of p-type and n-type semiconductors that convert heat into electricity via the Seebeck effect. Conducting polymers are a viable alternative with intrinsic advantages over their inorganic counterparts since they are abundant, flexible as thick-films, and have reduced manufacturing costs since they can be solution processed. Furthermore, polymers have an inherently low thermal conductivity, thus affording them the option of forgoing some heat exchanger costs. Current examples of polymer TE devices have been limited to traditional flat-plate geometries with power densities on the μW/cm2 scale, where their potential is not fully realized. Herein, we report a novel radial device and evaluate the improved performance of polymer-based TEG based on this architecture. Analytical heat transfer and electrical models are presented that optimize the device for maximum power density, and we obtain the geometry matching condition for this radial device that maximizes the module figure-of-merit. Our radial architecture accommodates a fluid as the heat source and can utilize natural convection alone (due to heat spreading) to obtain high power densities of 1–3 mW/cm2 using state-of-the-art polymer TEs subjected to a temperature difference of 100 K.
Design studies of a CZT-based detector combined with a pixel-geometry-matching collimator for SPECT imaging