Graphene Assembled Films for Radio Frequency and Microwave Technology

ConspectusWith the rapid advancement of information technology, an era of intelligence where seamless interconnectivity prevails is coming. The Internet of Everything (IoE) relies on efficient data transmission, wherein radio frequency (RF) and microwave technologies play a pivotal role. RF and microwave technologies spawn extensive applications in mobile communication, radar systems, remote sensing, and other fields. Traditional conductive materials in RF and microwave electronics include copper, gold, and other metals. However, conventional metal-based electronics are constrained by inherent challenges such as susceptibility to oxidation, high density, restricted heat dissipation capacity, and insustainability, thereby impeding their ability to fulfill the requirements of next-generation RF and microwave electronics. Graphene assembled films emerge as a promising class of carbon materials with excellent electrical and thermal conductivity alongside remarkable mechanical stability, chemical inertness, and low density, which are highly suitable for utilization in RF and microwave electronics applications. RF and microwave electronics based on a graphene assembled film exhibit comparable electrical performance to the metallic materials while offering additional advantages such as lightweight, flexibility, corrosion resistance, enhanced heat dissipation efficiency, and fatigue resistance. These distinguished properties enable electronics to adapt to intelligent environments with high integration levels. Therefore, the application of the graphene assembled film has significantly advanced the progress in RF and microwave technology, facilitating metal-substitution.In this Account, we primarily summarize our efforts toward developing the utilization of graphene assembled film (GAF) within the realm of electronics in RF and microwave technology. Through material optimization, device design, and processing technology iteration, we have successfully implemented GAF electronics in wireless communication, wearable systems, electromagnetic protection, and the intelligent control of electromagnetic waves in RF and microwave technology. First, we introduce the advanced properties of graphene and present an overview of the fabrication methods for GAF, including coating, vacuum filtration, and graphene oxide film reducing, highlighting exceptional electrical, mechanical, and thermal properties of GAF, as well as the feasibility of metal substitution. Subsequently, we extensively discuss the application of GAF in radio frequency and microwave technology from various perspectives, encompassing antenna and antenna arrays, flexible electronics, radio frequency identification (RFID) devices, and metasurfaces. GAF-based electronics not only inherit the exceptional lightweight, flexible, corrosion resistance, and fatigue resistance characteristics of GAF but also exhibit superior electrical properties, such as low radiation sidelobe and wide working bandwidth, surpassing the conventional metal-based devices. Finally, we discuss the bottlenecks associated with current GAF-based RF and microwave electronics as well as prospects, providing valuable insights for subsequent research endeavors and industrial advancements.