A review on polymers and their composites for flexible electronics

Flexible electronics have become an important trend in the information era. Consequently, the utilization of conventional metals and inorganic semiconductors is restricted in flexible devices due to their poor stretchability and adaptability. Thus, currently, it is urgent to find suitable candidates to at least partially replace these traditional components. In this case, polymers and their composites are considered as key materials for the fabrication of flexible electronic devices due to their excellent mechanical and electrical properties in flexible substrates, interfacial bonding, and functional active components. In this study, based on the important application value of polymers and their composites, non-functional materials such as substrate materials and adhesive materials, and functional materials including piezoelectric composites, conductive composites, and dielectric composites are summarized comprehensively. In addition, the structural features, performances, advantages, and disadvantages, as well as the main application scenarios of several common polymers are summarized in detail. Finally, we critically analyze the challenges and present future perspectives regarding polymers and composites for flexible electrics, aiming to realize their real applications.