Highly sensitive, durable and stretchable plastic strain sensors using sandwich structures of PEDOT:PSS and an elastomer

Thin-film "plastic'' strain sensors can be mounted closely on textile clothing or human skin comfortably to detect human activities without any harm to the human body. However, it is a grand challenge to prepare highly sensitive and durable plastic strain sensors. Herein, we report a high-performance plastic strain sensor with a sandwich structure of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) doped with poly(vinyl alcohol) (PVA-PEDOT:PSS)/highly conductive PEDOT:PSS/polydimethylsiloxane elastomer. The strain sensor exhibited not only high sensitivities but also good durability at large strains owing to its robust structure integration and strong recoverability in conductance. More importantly, our plastic strain sensors are successfully used to monitor a series of human activities including joint/muscle motions, arterial pulsation and voice vibration, and distinguish some complex and diverse bending motions, demonstrating great potential in practical applications.