Fully 3D-printed PVDF-TrFE based piezoelectric devices with PVDF-TrFE-rGO composites as electrodes

Direct ink writing (DIW) is a promising additive manufacturing (AM) technique in the field of microsystems technology due to the potential for high detail resolution and the wide choice of materials suitable for the technique. In this study, inks of polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) as well as composite inks with reduced graphene oxide (PVDF-TrFE-rGO) were developed and adapted for continuous flow DIW. The composite PVDF-TrFE-rGO inks achieved percolation after 1.5 wt% and electrical conductivity of 2.8 S/cm at the highest loading investigate in this study (7 wt%). The inks were successfully printed with minimum nozzle diameter of 40 μm on different substrates including glass, metal and a nitrile elastomer. It was also demonstrated that the inks can be used to create a fully 3D-printed piezoelectric device with the predicted response, i.e. the fabrication technique did not deteriorate the functionality of the device. The conductive composite ink was successfully utilized as an effective electrode in the device. It was therefore demonstrated that by combining materials, such as the composite PVDF-TrFE-rGO ink and the co-polymer PVDF-TrFE with additive manufacturing techniques, the fabrication of low-cost, versatile devices can be achieved.