Radio frequency micro-electromechanical systems is a multidisciplinary research domain concerned with the design, fabrication, and application of micro-scale devices that integrate mechanical structures with radio frequency electronic circuits. This field investigates the fundamental principles governing the interaction between mechanical motion and RF signals, exploring novel device architectures, materials, and manufacturing processes to achieve high-performance, compact, and reconfigurable components for wireless communication, radar, and sensing systems, thereby enabling miniaturization and enhanced functionality beyond traditional solid-state technologies.