Fabrication of Millimeter Thick Polymer‐Based Thermoelectric Devices by Solvent‐Free Printing

Abstract

Solution‐processable polymer‐based materials allow the fabrication of flexible, light‐weight, and large‐area thermoelectric devices (TEDs). However, solution fabrication processes of polymer‐based materials involve the drying of an organic solvent, which induces an unfavorable material orientation and hinders the formation of a thick thermoelectric layer. These limitations significantly deteriorate the performance of polymer‐based TEDs. In this paper, a polymer‐based TED, fabricated by solvent‐free printing (SFP)—a technique that eliminates the solvent drying process—is reported. A carbon nanotube (CNT)–polymer composite, which is a typical polymer‐based thermoelectric material, has been fabricated by a two‐step process. The deposition of a suspension, composed of CNTs and a liquid polymer precursor, on a substrate is followed by the solidification of the liquid polymer precursor via a cross‐linking reaction. This technique does not involve the drying of organic solvents. Therefore, thermoelectric materials with random material orientation and thicknesses of greater than 1 mm are obtained. The SFP‐fabricated polymer‐based TED exhibits an electric power that is more than four orders of magnitude higher than that of a thin‐layered TED fabricated via a conventional solution process. This work facilitates the realization of various applications of polymer‐based TEDs, such as wearable power sources that can convert body heat to electricity.

Inorganic‐Based Printed Thermoelectric Materials and Devices

“…For ink preparation, the solution-based wet chemistry method is one of the promising synthesis routes as it helps improve the surface chemistry of the ink. [158] Appreciable results from TE inks [159,160] and printed devices [161][162][163][164][165][166] prepared with different compositions and different recipes have been reported in recent times, but extensive research on the same is needed to overcome [76] (reproduced with permission, copyright 2012, ACS publication). b) TE cooling device made of Bi 0.5 Sb 1.5 Te 3 /epoxy thick films, and c) The temperature difference achieved as a function of time with different applied currents [152] (reproduced with permission, copyright 2018, Elsevier).…”

“…For ink preparation, the solution‐based wet chemistry method is one of the promising synthesis routes as it helps improve the surface chemistry of the ink. [ 158 ] Appreciable results from TE inks [ 159,160 ] and printed devices [ 161–166 ] prepared with different compositions and different recipes have been reported in recent times, but extensive research on the same is needed to overcome the difficulties. Some of the widely used dopants like Te, though they helps to improve TE properties, are very harmful to the environment.…”

3D-printed Bi2Te3-based Thermoelectric Generators for Energy Harvesting and Temperature Response

“…The thermoelectric materials of conventional in-plane thermoelectric generators were typically fabricated through methods, such as hand application, thermal evaporation, magnetron sputtering, − screen printing, − and filtration . For example, Li et al.…”

Continuous Phase Change Materials for Power Generation from Daily Air Temperature Cycles

“…In comparison with commercially available energy harvesters, such as photovoltaic devices, [1][2][3] thermoelectric devices (TED), [4][5][6][7] and vibration-based power generators [8][9][10] (whose harvesting energy, that is, light, heat, and vibration, exists at a limited location and time), power generators based on daily temperature cycles can facilitate the semi-permanent operation of various electronic devices (like wireless sensors) anywhere.…”