Performance Improvement of Flexible Thermoelectric Device: FEM-Based Simulation

Possibilities for improving the performance of the flexible thermoelectric (TE) device were discussed on the basis of heat conduction analysis by the finite element method. The flexible TE device consists of two flexible substrates and thin films of n- and p-type TE materials placed between the substrates. To enhance the device performance, the use of higher-performance TE materials and improvement of the flexible substrate will be effective. In the present study, the effect of the thermal conductivity of the materials used in the device on the output voltage was examined. The calculations indicated that there is a certain combination of thermal conductivities of the components which gives the maximum output voltage. Although a lower thermal conductivity of the TE material leads to higher output voltage, influence of the thermal conductivity on the maximum voltage was not significant under the condition of the present study. As a result, it is effective to improve device performance by choosing an appropriate combination of TE material and substrate material. According to the calculations, approximately 60% increase in output voltage is expected compared with that of the present combination of materials used in the prototype device.