Biodegradable screen-printable ink from coconut shell-derived activated carbon for sustainable packaging and flexible electronics

The extensive use of single-use food packaging products has increased demand for biocompatible alternatives and eco-friendly inks, thereby reducing the environmental impact of solvent-based, non-biodegradable, and toxic ink formulations. In this work, biodegradable, low-cost, screen-printable inks were developed using coconut shell-derived activated carbon and cellulose acetate propionate-based binder. Three different inks were prepared, with 30, 40, and 50 wt percentages of activated carbon. The formulated inks were tested for their optical, electrical, rheological, and biodegradability properties, and printability was analysed on different packaging materials and for flexible electronic applications. The result of this study confirmed that a formulated ink with 40 wt percentage of activated carbon has exhibited superior rheological, optical, biodegradability, and print properties for screen-printing, and can be used for direct printing on fruits, single-use packaging products, and flexible printed electronics.