Thermal impedance analysis of nano-dipole linear arrays for energy harvesting applications

•Thermal impedance response of nano-dipole linear arrays for energy applications.•Thermal impedance variations on polyimide (PI) and silicon dioxide (SiO2) substrates.•Couple fabrication method of e-beam lithography with FIB deposits of nanomaterials.•Simulated thermal response of nano-dipole arrays through finite element simulation.•Higher thermal impedance (Zth) values for PI as compared with (SiO2) substrates. Efficient thermal harvesting energy applications, based on the Seebeck effect, require systems with high thermal impedance to enhance both the thermal and electric response. In this work, we study the thermal impedance (Zth) response on steady conditions of metal dipole nanoarrays fabricated on polyimide and silicon dioxide (SiO2) substrates by electron beam lithography. The experimental thermal characteristics of the nanoarray, measured with a thermal camera, reveals a high delta temperature of 89.8 °C. and a high thermal impedance of 292.2 (K/W) in polyimide, in contrast with the ones obtained in SiO2, which were around 63.9 °C and 13.5 (K/W), respectively. In addition, numerical simulations were performed using COMSOL multi-physics software. The numerical results support a higher thermal impedance in polyimide that the one for SiO2. These results show that polyimide could be better thermal responsive substrate for thermal harvesting energy applications compared with its counterpart fabricated on SiO2.