Highly stretchable strain sensors based on polypyrrole-silicone rubber composites for human motion detection

Flexible strain sensors attained significant attraction due to their numerous applications, such as personal healthcare, robotics, human entertainment technology and sports performance monitoring. However, there still exist challenges to find out a strain sensing mechanism with a facile and cost-effective method. Polypyrrole (PPy)/SR composites were prepared by a simple, low-cost solution casting method. Carbonaceous fillers, graphene nano platelets (GNP), and carbon black (CB) were introduced along with PPy and the sensor performances including stretchability, flexibility, gauge factor (GF), linearity and durability were studied. PPy/SR composites showed a GF between 1.2 and 1.7 and exhibited reversible and stable electromechanical characteristics with an average response time of 150 milliseconds. The conductive mechanism, which causes piezoresistivity and the temperature-dependent resistance characteristics and mechanical properties, were studied. The excellent composite properties, such as super-stretchability, flexibility, biocompatibility, durability along with facile production and environmental stability, make them an ideal candidate for the fabrication of large strain wearable sensors which can be integrated to clothes or directly attached to the human body for real-time human body deformation measurements. (C) 2020 Elsevier B.V. All rights reserved.