Sustainable Soft Electronics with Biodegradable Regenerated Cellulose Films and Printed Recyclable Silver Nanowires

Abstract

This study describes the production of biodegradable and recyclable flexible electronic devices created by screen-printing silver nanowires (AgNWs) onto regenerated cellulose films (RCFs). RCFs, derived from microcrystalline cellulose (MCC), are developed and further enhanced for flexibility with additives such as glycerol and poly(ethylene glycol) diglycidyl ether (PEGDE). The resulting cellulose films display relatively high tensile strength (up to 120 MPa), low Young's Modulus (down to 1500 MPa), and 90% optical transparency. Ink with AgNWs and poly(ethylene oxide) (PEO) as a binder is screen-printed on regenerated cellulose films. The printed AgNWs patterns exhibit high electrical conductivity, excellent electromechanical performance, and strong interfacial adhesion with RCFs. To demonstrate the application of printed AgNWs on RCFs for soft electronics, transparent conductive electrodes (TCEs) are fabricated. Grid and honeycomb structures are printed separately and evaluated in terms of sheet resistance and optical transparency. TCEs with ≈80% transparency and very low sheet resistance (0.045 Ω sq⁻¹) are obtained. Furthermore, enzymatic hydrolysis of the cellulose substrate and the recovery for reuse of the AgNWs are demonstrated, showing the potential of integrating natural polymers and recyclable nanomaterials for eco-friendly and sustainable soft flexible electronics.