To allow for optimal wetting of the inks and stability in aqueous solutions, a polymer was first printed to aid adhesion. A tri(proplylene) glycol diacrylate (TPGDA) ink was used, which had been modified to polymerise under UV light. For this purpose, a UV light was mounted onto the print head (365 nm and 6000 mJ cm -2 , Printed Electronics Ltd.). To prevent polymerisation inside the cartridge, the reservoir was sealed with duct tape. Ag nanoparticle (AgNP) ink (Advanced Nano Products Ltd.) with a solid content of ~30% was used for printing conductive tracks. An in-house heated substrate was used to heat the ink to 100 o C during printing; full sintering was performed using a 200 o C oven Five layers of TPGDA were printed to allow for a level surface. Three layers of AgNP ink were printed to improve conductivity, yet still, allow for a short print time. Waveforms used for each ink were optimised and can be seen in Figure A+B. The print resolution was 846.67 drops per inch, corresponding to a drop spacing of 30 μm. The firing voltage varied over a range of 24-30V.