Flexible biodegradable wearables based on conductive leaf networks

Electronic waste (E-waste) pollution is a global environmental problem because it contains various contaminants, including hazardous heavy metals and toxic chemicals. These contaminants may accumulate in the environment and pollute oceans worldwide, seriously threatening the environment and human health. Besides, agricultural wastes burning from straw and leaves may be the most significant contributor to haze particulate matter (PM) air pollution in developing countries. Developing biodegradable green electronics based on the circular economy principle is an ideal solution to address the above waste-related environmental issues. In this study, we report on a biodegradable conductor, integrating Poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)-based nanocomposites into leaf skeletons (used as substrates). In addition, the effective drop-casting technique is used to prepare biodegradable conductors for potential utility in lightweight wearable devices. The biodegradable conductor exhibits a remarkable sheet resistance of 2.4 ± 0.6 Ω sq.⁻¹ with one drop-casting step. Raman spectroscopy demonstrated that the enhanced electrical performance of the conductive leaf is attributed to an increase in the predominant quinoid structure of PEDOT chains. It is proved that this high-performance biodegradable conductor can be applied as a promising component for various next-generation wearable electronics, including electrocardiogram (ECG) electrodes and flexible strain sensors, demonstrating promising potential for the development of United Nation's Sustainable Development Goals (SDGs) in green electronics.