Synthesis of conductive microcapsules for fabricating restorable circuits†
Three types of conductive microcapsules are proposed; they all contain the same phase change material, eicosane, as the core and have different conductive shells with various types of nano silver (Ag) coatings. Due to the Ag coating, these microcapsules are highly compatible with commercial Ag pastes and nano Ag ink and show an improvement of almost 500% in mechanical strength. When an electrical circuit is incorporated with these conductive microcapsules, it exhibits at least 70% lower electrical resistivity than when incorporated with insulated microcapsules. In addition, a restoration efficiency of higher than 90% in the electrical current of a damaged circuit is achieved when 20 vol% conductive microcapsules are incorporated. Based on their excellent mechanical and electrical properties, the proposed conductive microcapsules are capable of being directly mixed with inorganic Ag particles, and show the capacity for being used as self-restorable ink for conductive inkjet printing.