Thermoelectric textile devices with thin films of nanocellulose and copper iodide

Owing to the rapid development of wearable electronics and smart textiles, demands for flexible and wearable thermoelectric (TE) devices, which can generate electricity in a ubiquitous, unintermittent and noiseless way for on-body applications are growing rapidly. Due to the inherent flexibility and wearability features, textile-based thermoelectric generators (TEGs) possess significant potential for biomedical and consumer health and safety applications. In this study, using commercial cotton fabric, we created efficient thermoelectric (TE) textile that, unlike analogs, is based on thin-film composite of biocompatible semiconductor copper iodide (CuI) and biodegradable polymer nanocellulose (NC_p) obtained by processing a widespread plant common reed. The CuI films with average thickness 10 µm were deposited via low-temperature aqueous cheap, facile, and scalable fabrication technique Successive Ionic Layer Adsorption and Reaction (SILAR). The NC_p sublayer made it possible to fabricate thin-film ohmic contacts through vacuum deposition of chromium on the nanostructured CuI film in the TE textile. The topping of CuI film with NC_p layer improved durability and wear resistance of the wearable thermoelectric module fabricated with this TE textile. The developed TE module has shown output power density 44 µW/cm² at temperature gradient 50 K that is among the best currently known results for solid miniature flexible and fabric-based TEGs.