Eco-friendly phyllanthus emblica-based ionic polymer composite for enhanced mechanical, electrical, and wearable sensing performance

Abstract

In this intelligent society, wearable technology is in high demand. Long-term contact between these wearable gadgets and the human body creates a demand for the eco-friendly flexible sensors. Here, for the first time, an ionic polymer composite (IPC) based on eco-friendly phyllanthus emblica (PE, Indian gooseberry) liquid extract and polyvinyl alcohol (PVA) is proposed for wearable sensing applications. Because of the ionic conducting elements such as sulphur (S), oxygen (O), iron (Fe), magnesium (Mg), and the presence of fibers in the PE, the PVA/PE IPC with a blending ratio of 1/11 generated 1.5 × 105, 18, and 1.86 folds of higher dielectric constant, ionic conductivity and higher tensile strain than that of the PVA sample. The PVA/PE IPC membranes could not dissolve in water for a month and maintain elasticity. The 1/11 IPC sensor also exhibited 28 folds higher sensitivity (ΔR/R = 0.45) and gauge factor (G = 51) than that of the PVA sample and was beneficial for piezoresistive applications. When the IPC sensor was placed on the human neck and fingers, signals were detected from breathing and finger-bending-induced strain, making it feasible for wearable devices. The motion test of IPC showed proper variation in sensing resistance when IPC encountered a motion, which is highly suitable for wearable devices. The proposed IPC is an eco-friendly option for piezoresistive applications such as wearable sensors and eco-friendly ionic skins.