Highly tailorable, ultra-foldable, and resorbable thermoelectric paper for origami-enabled energy generation

Recently, owing to the increased focus on environmental initiatives such as the green campaign and green economy, thermoelectric (TE) energy harvesting technology using polymer-based TE materials has attracted significant attention. Among the various polymers used in TE materials, cellulose plays a crucial role in substituting petroleum-based polymers as it is an abundant natural organic biomass resource. Herein, we first developed the origami and kirigami-enabled resorbable TE paper, with a self-assembled inorganic particle network layer below the cellulose polymer bio-matrix layer, through a simple drop-casting process. The prepared p- and n-type TE papers exhibited relatively high-power factor values of 3.11 and 1.16 μW·m⁻¹·K⁻², respectively, at 298 K. Furthermore, the fabricated flexible TE energy harvester (f-TEH) achieved an output performance of 38.55 mV, 12.14 μA, and 95.17 nW for a temperature difference of 24 K without the degradation of electrical and mechanical stability. Finally, we demonstrated the high applicability of TE papers in TEHs of complicated shapes by cutting or folding the materials and analyzing their TE performance. We believe that the results of this study not only present a breakthrough in designing tailorable and foldable TEHs for energy harvesting applications but also have significant implications in the field of green technology.