Stable large area drop-on-demand deposition of a conductive polymer ink for 3D-printed electronics, enabled by bio-renewable co-solvents

Abstract

Development of conductive polymer ink formulations with reliable jetting stability and physical properties could offer sustainable routes for scaling-up the 3D-printing of electronics. We report a new poly(3,4-ethylenedioxythiophene) polystyrene sulphonate (PEDOT:PSS) ink formulation, InkCG, using bio-renewable solvents dihydrolevoglucosenone (cyrene) and glycerol carbonate (GC) as an alternative to commonly used dimethyl sulfoxide (DMSO). These green organic co-solvents enhance jetting reliability and long-term stability of the ink and improve electrical properties of the deposited PEDOT:PSS layers, compared to the commonly used DMSO-containing ink formulations. We achieve large-area and high-fidelity electronic devices (array of 140 devices) with reproducible electrical performance through inkjet-based 3D printing. Enhanced performance stability is observed under cyclic bending, thermal annealing, UV or IR exposure, offering exciting opportunities for sustainable deposition of PEDOT:PSS for large-area 3D printing and its exploitation in heterostructures and flexible electronics.