The effect of printing parameters on the bonding strength and electric performance of FDM-printed graphene filaments to mulberry paper for paper electronics

Environmental concerns arising from industrial growth, and in particular the accumulation of waste and toxic substances, have prompted the demand for sustainable and ecofriendly solutions. Cellulose, known for its ecological attributes, is a cost-effective and recyclable material that is suitable for replacing silicon substrates, particularly in flexible electronic devices. However, the limitations of 2D techniques, such as inkjet and screen printing, necessitate the adoption of 3D printing technologies in this domain. This study introduces a novel approach utilizing fused deposition modeling printing (FDM) to create a mulberry paper (MP)-graphene filament strain sensor. This process involves the melting and extrusion of multifunctional filaments, which requires a meticulous examination of the bonding between MP and polymers. To optimize the bonding between MP and graphene filaments, adjustments were made to the nozzle and platform temperatures, as well as the printing gap, resulting in a substantial binding strength of 3.85 N, exceeding that of conventional paper by more than 2.5-fold (1.58 N). Leveraging this impressive binding strength, the strain sensor achieved a remarkable gauge factor of approximately 648 and commendable linearity of 0.94. The practical application of the FDM-based MP-graphene filament strain sensor in a household wind speed sensing system showed promising results within a wind range of 8.9–9.4 m/s. The integration of cellulose-based MP and graphene filaments via FDM printing is a pivotal advancement in the development of eco-friendly high-performance strain sensors, offering potential solutions to environmental concerns and application in flexible electronic devices.