Recent progress in conductive self-healing hydrogels for flexible sensors

Abstract

Flexible sensors have great potential in the application of wearable and implantable devices, and conductive hydrogels have been widely used in wearable sensing devices due to their biomimetic structure, biocompatibility, adjustable transparency and stimuli-responsive electrical properties. Conventional conductive hydrogels are prone to be damaged in their application process and lack of long-term reliability. Inspired by natural organisms such as mussels, introduction of self-healing capabilities has been regarded as a promising approach to extend the service life of hydrogel sensing devices. This work reviews the synthesis methods and the associated self-healing mechanisms of representative conductive self-healing hydrogels. The sensing principles and structural design of conductive hydrogel sensors are also reviewed and their applications for in vivo/in vitro signal monitoring are introduced. The remaining challenges and perspectives in this field are discussed in order to direct the future research on the integration of self-healing capabilities, good sensing properties and excellent mechanical performances into flexible sensors.