Wearable thermoelectric generator with vertically aligned PEDOT:PSS and carbon nanotubes thermoelements for energy harvesting

Abstract

Summary Thermoelectric generators (TEGs) facilitate maintenance‐free sustainable energy transduction, making them attractive and feasible options for self‐powered wearable electronics. Nonetheless, their energy‐conversion process suffers from inadequate design and rigidity owing to the use of brittle inorganic materials, making them inapt for wearable applications. Thus, the development of a TEG made of flexible materials with high deformability is required. In this study, a novel wearable TEG was designed and fabricated with vertically aligned p‐type PEDOT:PSS and n‐type SWCNT film‐based thermoelements. Finite element analysis was used to optimize the thermoelement length, which was essential for enhancing the overall TEG output performance. This study also examined the effects of acid‐based post‐treatment and polyethylenimine concentration on the thermoelectric properties of PEDOT:PSS and SWCNT films, respectively. As a proof of concept, the proposed TEG, composed of five pairs of thermoelements, generated an open‐circuit voltage of 1.75 mV while produced a maximum power and a power density of ~6.1 nW and 10.17 nWcm−2, respectively, at a ΔT of 11.24°C by harvesting energy from the wrist. The proposed design represents a significant step toward developing a next‐generation flexible organic TEG that can pave the way for self‐powered wearable electronics in a sustainable manner utilizing body heat.

Recent Advances in Carbon Nanotube‐Based Energy Harvesting Technologies

“…Reproduced with permission. [ 129 ] Copyright 2022, John Wiley and Sons. k) Schematic of a stretchable TEG architecture.…”

A Cross‐Plane Design for Wearable Thermoelectric Generators with High Stretchability and Output Performance

“…[4,16,17] Hence, many researchers begin to develop 3D cross-plane flexible TEGs, where the films are arranged along the vertical heat flow direction. [18] Stretchability deemed as another important characteristic is closer to the realistic wearability in comparison with flexibility, [19][20][21] since the low-degree deformability of flexible thermoelectric generators still fails to accommodate the local strains and distortions yielded by multidirectional movements of the curve skin surface (up to 15%) and joint rotation (up to 50%). [2,22] Benefiting from the mature textile technology, integrating flexible TE materials with textiles can be served as one of the most efficient methods to achieve large coverage for wearability.…”

“…[ 4,16,17 ] Hence, many researchers begin to develop 3D cross‐plane flexible TEGs, where the films are arranged along the vertical heat flow direction. [ 18 ]…”

Boosted Output Voltage of BiSbTe‐Based Thermoelectric Generators via Coupled Effect between Thermoelectric Carriers and Triboelectric Charges

“…[12,13] For sustainable generation of the power required in practical environments, hybrid and multisource energy-harvesting technologies have attracted substantial attention for their ability to continuously harvest energy and increase power output. [14][15][16][17] Among the energy harvesting technologies that have been reported thus far, TEGs have a number of advantagesincluding simplicity, [18,19] minimal maintenance requirements, [20,21] low cost, [22,23] and reliability, [24,25] that make them a good solution for sustainable power supply from waste heat sources. [26,27] From micro-electronics to industrial furnaces, numerous types of waste heats ranging from room temperature to high temperature (>600 °C) can be recovered into electricity by thermoelectric power generators depending on the materials.…”

“…Among the energy harvesting technologies that have been reported thus far, TEGs have a number of advantages—including simplicity, [ 18,19 ] minimal maintenance requirements, [ 20,21 ] low cost, [ 22,23 ] and reliability, [ 24,25 ] that make them a good solution for sustainable power supply from waste heat sources. [ 26,27 ] From micro‐electronics to industrial furnaces, numerous types of waste heats ranging from room temperature to high temperature (>600 °C) can be recovered into electricity by thermoelectric power generators depending on the materials.…”