Wearable Thermoelectric Devices Based on Three-Dimensional PEDOT:Tosylate/CuI Paper Composites

Abstract

Thermoelectric composites of organic and inorganic materials exhibit significantly enhanced thermoelectric properties compared with pristine organic thermoelectrics so they might be better suited as core materials of wearable thermoelectric devices. This study describes the development of three-dimensional (3D) paper PEDOT:tosylate/CuI composites that could be shaped as 3 mm thick blocks to convert a temperature difference between their bottom and top sides into power; the majority of organic thermoelectric materials are shaped as thin strips usually on a planar substrate and convert a temperature difference between the opposite edges of the strips into power. The 3D paper PEDOT:tosylate/CuI composites can produce a power density equal to 4.8 nW/cm2 (ΔΤ = 6 Κ) that is 10 times higher than that of the pristine paper PEDOT:Tos composites. The enhanced thermoelectric properties of the paper PEDOT:tosylate/CuI composites are attributed to the CuI nanocrystals entrapped inside the composite that increases the Seebeck coefficient of the composite to 225 μV K–1; the Seebeck coefficient of paper PEDOT:Tos is 65 μV K–1. A proof-of-concept wearable thermoelectric device that uses 36 blocks of the paper PEDOT:tosylate/CuI composites (as p-type elements) and 36 wires of monel (as n-type elements) can produce up to 4.7 μW of power at ΔΤ = 20 K. The device has a footprint of 64 cm2 and can be placed directly over the skin or can be embedded into clothing.

High-Performance Paper-Based Thermoelectric Generator from Cu2SnS3 Nanocubes and Bulk-Traced Bismuth

“…Previously, Syafiq et al also constructed a TEG with CTS (synthesized via a ball milling process) and AZO (aluminum-doped zinc oxide) on soda-lime glass that produced an output power of 75 nW at Δ T = 160 K with an output power density of 0.3 nW cm –2 K –1 , although the TEG device was not flexible or environmentally safe paper-based due to the rigidity of the substrate . The output power measured from our flexible 20-pair CTS NC film-pressed Bi film PTEG assembled by Kapton as reported in this work (Table S2) thus generates significantly high output power and power density as compared to any recent related PTEG work and is also comparable to other contemporary thin film TEGs as shown graphically − in Figure d and as tabulated in Table S3 in the Supporting Information. It clearly indicates the excellent performance of our reported PTEG with added advantages of economic and easier fabrication methods on stationery emery paper and chemically synthesized pure phase earth-abundant elements-based nanocrystalline CTS, which was not studied before for flexible TE applications.…”

Flexible solar and thermal energy conversion devices: Organic photovoltaics (OPVs), organic thermoelectric generators (OTEGs) and hybrid PV-TEG systems

“…Also, the developed three-dimensional paper PEDOT: tosylate/CuI composites resulted in a power density of 4.8 nW cm − 2 at ΔΤ = 6 Κ. This value was 10 times higher than that of the pristine paper PEDOT:Tos composites [506]. This significant improvement was attributed to the addition of the CuI nanocrystals that increase the Seebeck coefficient from 65 μV K − 1 to 225 μV K − 1 .…”

Wearable Thermoelectric Generators: Materials, Structures, Fabrications, and Applications

“…[77] Among these polymers, PEDOT and its derivatives have been widely explored and exhibit important roles because of their stability, relatively high electrical conductivity (%300 S cm À1 ) and, especially manufacturability. [86,87] The major drawback of PEDOT is its solubility, which can be enhanced using a water-soluble polyelectrolyte, poly(styrene sulfonic acid) (PSS), as the charge-balancing dopant during polymerization. [88] In addition, due to the good film-forming properties and satisfied stability, PEDOT and its derivatives have been widely studied and some representative results are shown in Table 1.…”