Recyclable and biodegradable smart electronic circuits on flexible substrates

Direct ink writing is an innovative technique developed to replace traditional fabrication techniques, such as lithography, for flexible electronics. Herein, a novel ternary cadmium sulfide quantum dot-doped reduced graphene oxide-bismuth oxide (CrGB) heterojunction semiconductor material was prepared via an in situ hydrothermal technique. After that, an electroconductive ink consisting of carbon nanotubes (CNTs) and CrGB was prepared. The ink was used to fabricate a flexible circuit using nanocrystalline cellulose (NCC) paper. The circuit exhibited excellent conductivity of 3900 S cm(-1). Furthermore, the recyclability and biodegradation of the circuit suggest the feasibility of constructing low-cost and environmentally benign materials and devices.