3D Printed Gelatin Methacrylate Hydrogel‐Based Wearable Thermoelectric Generators
Ching‐Chieh Hsu, Yen‐Ting Lin, Shao‐Huan Hong, U‐Ser Jeng, H. B. Chen, Jiashing Yu, Cheng‐Liang Liu
Abstract
Abstract The present study focuses on the utilization of a hydrogel consisting of gelatin methacrylate (GelMA) and polyvinyl alcohol (PVA) as a matrix for hosting the redox couple Fe(CN) 6 3−/4− . The hydrogel exhibits a discernable thermopower ( S rc ) of 3 mV K −1 . The beneficial effect of the hydrogel microstructure on the mechanical robustness is demonstrated by small‐angle X‐ray scattering (SAXS). Moreover, the hydrogel is used to construct a 3D printed thermoelectric generator (TEG) consisting of eight p‐type thermoelectric legs, which exhibits commendable thermoelectric properties, including an open‐circuit voltage of 64 mV and a power density of 4.0 mW m −2 under a temperature gradient (Δ T ) of 2.5 K. These findings demonstrate that 3D printing both enhances the quality of the interface between the hydrogel and electrode and provides a promising method for a more facile TEG fabrication process with the potential for further applications in low‐grade waste heat harvesting.