PVA/CMC/PEDOT:PSS mixture hydrogels with high response and low impedance electronic signals for ECG monitoring.

Skin-like electronics on human skin can be operated in real-time and in a non-invasive manner for ECG biosensors. Conductive hydrogels possessing high electrical conductivity, soft and moisturizing properties, have great potential in this field. Herein, we propose to use polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) as the skeleton of the hydrogel, the polyethylene-3,4-dioxythiophene:sodium polystyrene sulfonate (PEDOT:PSS) mixture is evenly dispersed among it to form a continuous and interconnected conductive pathway. The prepared conductive hydrogels have an electrical conductivity of 75 S m-1 with high water content (above 80 %) and mechanical properties, leading to sufficiently soft and moisturizing, and can take place of traditionally high-cost Ag/AgCl electrodes. Importantly, these conductive hydrogels are similar to human tissues and can form a naturally seamless interface between the human body and the ECG biosensor device, promoting the high response of obtained electronic signals with low impedance. Therefore, these functionalized conductive hydrogels show excellent application prospects in ECG biosensors.