Stretchable conductors are fascinating new materials, because they can maintain the electrical characteristics when stretched or deformed. The development of stretchable conductors opens up the possibility of utilizing electronic devices in various areas such as portable healthcare devices, skin patch sensors and/or wearable electronic devices. Although many researches on development of stretchable conductors are underway, the electrical properties and stretchability must be further improved in order to be used as electronic devices. In this study, new strategies were utilized to improve the performance of stretchable conductors by fabricating conductive fillers/stretchable matrix nanocomposites.
As a first research strategy, two types of hybrid fillers were designed and fabricated for synergistic effects of conductive fillers. One type of filler is the CNT/Graphene hybrid filler. Through hybridization of the CNT and the graphene, the electrical network and the dispersion property of conductive fillers were improved. Due to these synergistic effects, CNT/Graphene hybrid filler have better electrical properties than CNT or graphene single filler in nanocomposites. The other is a Graphene/Silver nanowire (AgNW) hybrid filler. Through strong interaction of highly conductive AgNW with highly dispersible graphene and formation of core-shell structure, the Graphene/AgNW hybrid filler has superior electrical properties with high dispersibility in the stretchable matrix.
Another strategy is to fabricate highly conductive 3D nanostructures as conductive fillers of nanocomposites. As one of them, highly conductive AgNW/Graphene aerogel (GA) nanostructure was fabricated by forming uniform AgNW networks using the 3D porous GA. The other is the 3D controlled-porous AgNW nanostructure fabrication by ice template. The pore size control of the 3D AgNW nanostructure enables formation of dense AgNW network by low content of AgNWs. Through structure control of these 3D AgNW nanostructures and electrical enhancement of the AgNW network, stretchable and conductive nanocomposites having excellent electrical properties with high stretchability were fabricated.