Biopolymer film modification offers a sustainable approach to developing next-generation materials for soft electronics and packaging applications, addressing the need to reduce environmental impacts from synthetic nonbiodegradable polymers. We present two different ways of modifying biopolymers for this purpose. The first technique is plasticization in which plasticizers such as glycerol can be used to modify the molecular interactions within natural polymers such as agarose and chitosan. Glycerol disrupts the intra-molecular hydrogen bonding among the polymer chains and forms intermolecular hydrogen bonds. Consequently, the molecular chains gain higher mobility, resulting in increased material stretchability. In this study, agarose and chitosan films were investigated at varying biopolymer-to-glycerol ratios. As glycerol content increased, agarose films exhibited elongation beyond 60%, while chitosan films acquired up to 110% stretchability. The decrease in tensile strength brought their Young’s modulus to the same order of magnitude as human skin. The films demonstrated biodegradation in microbial environments and enzymatic conditions. Silver nanowires were used as conductive functional wiring for testing biopolymer-based electronic circuits. Layered film assembly is another technique for developing biomaterial-based barrier films for packaging. Layered films composed of agarose and shellac biopolymers were investigated. Shellac alone does not have good film-forming properties but can be used effectively as a protective hydrophobic coating on agarose. Agarose layers provided mechanical strength, while shellac offered superior barrier properties. The layered films showed moderate tensile strength values with stretchability of 35–42%. Water vapor transmission rates were found to be lower than most biopolymer-based barrier films. The films were heated above shellac’s glass transition temperature, which enabled their molding into various shapes, including box, tetrahedral, and cylindrical forms. The thermoformability opens the possibility of layered packaging films to be used in different forms and applications. The strategies of plasticization and layered film assembly demonstrate the potential of biopolymer film application in advancing sustainable solutions for both electronics and packaging, paving the way toward a circular economy.
