Flexible electrode materials for emerging electronics: materials, fabrication and applications

Abstract

With the swift evolution of smart products, flexible electronics characterized by their light weight, high flexibility and superior extensibility are becoming more and more fashionable in our daily life. As the foundational elements of flexible electronics, flexible electrodes have made a big splash in recent years in diverse fields of brain–computer interfaces, touch-screen displays, intelligent robots, and wearable and implantable devices. In this context, we analyzed the development of flexible electrode materials for electronics in the last 10 years by literature visualization. Our central emphasis is on all aspects of flexible electrodes, with a primary focus on flexible substrates (hydrogel/aerogel, fiber/fabric, polymer films) and active materials (metal and derivatives, carbon-based materials, MXenes, MOFs, etc.). Further, we extensively discuss the manufacturing methods of flexible electrodes, involving printing, vacuum filtration, deposition, electro/chemical plating, and others. The flexible electrodes have the potential to address a wide range of applications in flexible sensors, energy storage, and healthcare. Overall, the major challenges and future aspects of flexible electrodes are discussed for fabricating a new generation of flexible electronics.