<p>Surface Acoustic Wave (SAW) sensors are increasingly vital in modern technology due to their unique properties, adaptability, and wide applications. This research aims to improve the performance of SAW sensors by increasing mass loading sensitivity and addressing diverse interfacial imperfections. The enhancements aim to significantly improve the efficiency and precision of these sensors. This study examines the dynamic behavior of BG-type waves in piezoelectro-magnetic fiber-reinforced composite (PEMFRC) structures, considering two models: one with an air medium (Model-A) and another influenced by a coated thin film mass loading (Model-B). Central to this investigation is the role of electro-magneto-mechanical interfacial imperfections, categorized into five submodels: mechanically compliant with weak dielectric and magnetic properties (DWMW), high conductivity and permeability (DHMH), low dielectric and magnetic permeability (LDLP), grounded metallic with magnetic grounding (GMMG), and welded interfaces. A micromechanical model of the PEMFRC was developed, deriving effective material constants using advanced composite theory, iso-field approach, the strength of materials, and the rule of mixtures. Tailored boundary conditions for each imperfection enabled the formulation and validation of velocity equations. The study explores four electric-magnetic scenarios: electrically and magnetically short (ESMS), electrically short and magnetically open (ESMO), electrically open and magnetically short (EOMS), and both electrically and magnetically open (EOMO). Graphical analysis highlights electro-magneto-mechanical, electro-mechanical, and magneto-mechanical interactions, emphasizing the influence of mass loading, volume fraction, and imperfections on BG wave phase velocities. The outcomes of this research could revolutionize detection technologies in SAW devices, enhancing their application across diverse sectors such as industry, healthcare, consumer electronics, security, and defence.</p>