Design and Comparative Analysis of Highly Sensitive CNT/PIB/LiNbO ₃ Hetero‐Structure SAW Resonator

ABSTRACT This article provides a comprehensive performance analysis of various sensing layers on one‐port surface acoustic wave (SAW) resonators exhibiting mass loading effect. Lithium Niobate (LiNbO 3 ) piezoelectric substrate, polyisobutylene (PIB) polymer and carbon nanotube (CNT) based multilayer SAW sensors were considered for device sensitivity. This study contributes to understanding the CNT‐PIB composite layer on 128° YX‐cut LiNbO 3 SAW devices for sensing applications. This research proposed four different SAW structures with optimized geometrical boundary conditions. The finite element method is applied to solve the SAW device partial differential equation (PDE) to find the device performance parameters. The proposed one‐port SAW sensor has been analyzed with the investigation of change in SAW phase velocity, electromechanical coupling coefficient ( K 2 ), device sensitivity, admittance (Y11), S parameter (S11), and quality factor. Electrical response of the proposed SAW device is equivalently modeled with the modified Butterworth‐Van Dyke (mBVD) lumped parameters, motional resistance ( R m ), motional inductor ( L m ), motional capacitor ( C m ), and electrostatic capacitance ( C 0 ). The obtained mBVD parameter describes the proposed SAW device's behavior tuned to the desired sensitivity, frequency response and signal‐to‐noise ratio. High sensitivity of 18.7 MHz/µg is reported for the proposed device. The obtained mass sensitivity is compared and is more effective than the parallel research outcome.