Flexible thermoelectric generator with polydimethyl siloxane in thermoelectric material and substrate

•CNTs and Bi/Te powder were mixed in polydimethyl siloxane (PDMS) to develop a flexible thermoelectric material.•The PDMS used for the hybrid thermoelectric material was also used as the substrate.•Carbon nanotubes were used to enhance electrical conductivity.•The flexible thermoelectric generator maintained its performance during 1000 bending reliability tests.

In this paper, the fabrication and characterization of a flexible thermoelectric generator (TEG) is presented. Bismuth telluride powder (Bi/Te) is utilized as p- and n-type thermoelectric materials, and carbon nanotubes (CNTs) are used to enhance electrical conductivity. Both the CNTs and bismuth telluride (Bi/Te) powder are mixed with a solution of polydimethyl siloxane (PDMS) as a precursor. The same PDMS used for the hybrid thermoelectric materials is also used as the substrate, making the TEG flexible and increasing its stability. The Seebeck coefficients of the fabricated p- and n-type thermoelectric materials are 143 and -174 μV/K, respectively. The output voltage of the fabricated device is 920 mV and the generated power is 570 μW/cm2 with a temperature difference of 60 °C. The fabricated TEG maintains its performance level during bending reliability tests on a curvature with a radius as small as 5 mm, and after more than 1000 repetitions of bending on a curvature with a radius of 20 mm.