Stepwise Curing Induced All‐Stretchable Thermoelectric Generator of High Power Density

Abstract In this study, a wearable and highly stretchable organic thermoelectric (TE) generator with a notable power density is developed. A highly stretchable and solution‐processable TE/electrode pattern is realized by stepwise‐curing elastomeric and conducting network. Significant advances in the TE or electrical properties are obtained for these stretchable patterns through post‐activation treatment, which creates long‐range charge transport pathways without degrading pre‐established elastomeric networks. The TE and electrode patterns are solution‐processed to a stretchable template, so that all‐stretchable TE generator is realized. The fabricated TE generator maintains 90% of its maximum TE power output at 40% stretching stress and shows a stable TE power output after 200 stretching cycles. The TE generator maintains its stretchability in highly densified patterns, as the highly stretchable TE/electrode patterns enable good stretchability with little aid of the stretchable template. So, the TE generator has a high power density of 0.32 nW cm −2 K −2 , one of the highest values among stretchable TE generators to date.