Development of environmentally friendly flexible electronics based on ethyl cellulose – silver microflakes composite

• Eco-friendly composite with ethyl cellulose and silver microflakes was developed. • Composite enables low temperature curing and is fit for silver recycling. • Screen-printed layers showed low sheet resistance and strong adhesion to paper. • Bending increased resistance by 20%, but aging improved conductivity by 11% • Composite is fit for recyclable flexible electronics due to biodegradable matrix. This study reports the development of an electrically conductive paste for flexible printed electronics using a biodegradable ethyl cellulose (EC) matrix and silver microflakes, processed at low temperatures on paper substrates. The optimal composition — 10 wt% EC and 60 wt% silver — cured at 120 °C achieved a sheet resistance of 58 mΩ/sq with < 3 µm thickness and excellent adhesion. Increasing silver to 70 wt% lowered resistance to 46 mΩ/sq but reduced printability. Key properties evaluated included rheology, adhesion, conductivity, bending durability, and biodegradability. Over a 12-month period, the sheet resistance decreased by 11 %, while bending tests conducted over 1000 cycles resulted in a 20 % increase. 2-month biodegradation assays showed that silver-containing samples exhibited slower degradation rates, attributed to silver’s antimicrobial properties. The results demonstrate a promising, sustainable conductive paste based on a biodegradable matrix intended for low-temperature processing, balancing electrical performance and flexibility