Chitosan based aerogel fibers for piezoelectric and moisture electric energy harvesting

Taking advantages of renewable resourced materials in the preparation of multifunctional aerogel fibers which integrate thermal insulation , piezoelectric and moisture electric generation could be a promising way of relieving pressure on both energy loss and generation. A series of chitosan-konjac glucomannan (CS-KGM) aerogel fibers was obtained by means of wet-spinning method followed by freeze-drying. The CS-KGM aerogel fibers with submicron porous morphology exhibit excellent thermal insulation performance. Single layer of CS-KGM aerogel fiber with only a thickness of 0.6 mm shows a thermal insulation temperature difference of 23 °C. A stable piezoelectric output voltage of 0.35 V can be generated from a single CS-KGM aerogel fiber during a 500 press-release cycle attributing to the intrinsic piezoelectricity of CS and the porous structure. Single aerogel fibers were coated with multi-walled carbon nanotubes as a way to prepare conductive aerogels. Meanwhile, the moisture electric output voltage can be as high as 160 mV and last for >8 h at 60% relative humidity for CS-KGM single aerogel fiber assisted by a thin layer of carbon nanotube coating. Overall, CS-KGM aerogel fibers prepared in this work has good compatibility and potential applications in thermal management and energy harvesting from low density resource, which provides a new strategy for the preparation of sustainable and multifunctional wearable materials.