Flexible, stretchable, and highly sensitive piezoresistive strain sensors based on modified PEDOT:PSS layers with nickel microparticles

Abstract

Abstract Here, we describe the development and fabrication of a flexible, stretchable, and conductive piezoresistive strain sensor based on poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). This sensor, which can detect small strains, shows a remarkable sensitivity due to the presence of a layer of interconnected Ni microparticles (NiMPs) on its surface. Furthermore, polyvinyl alcohol (PVA) was used as a matrix to improve the elasticity of the conducting PEDOT:PSS membrane. Accordingly, a piezoresistive strain sensor composed of PEDOT:PSS, PVA and a layer of NiMPs (PEDOT:PSS/PVA/NiMPs) was fabricated and its electrical signal, stability and response time were studied at different strains and bending angles. NiMPs were stuck on the conducting polymer and distributed uniformly by a very simple and costless method using a magnetic stirring bar magnet. The applied strains varied from 0–28%, which is the typical range of human body movements (arms, fingers, knees, and feet, facial expressions and breathing rate). The experimental results show an outstanding performance of the sensors compared with other strain sensors based on PEDOT:PSS.