Research article

STUDY OF SAW-BASED HYDROGEN GAS SENSOR USING VARIOUS IDT MATERIALS AND GEOMETRY

Nimmala Harathi1, Kavitha Subramanian1* and Argha Sarkar2 and Rajakumar Selvarajan3

Online First: November 30, 2022


A 2D model of a SAW sensor is simulated using a variety of Inter Digitized Transducers (IDT) materials, with IDT heights varying from 100 to 150µm. Surface acoustic wave production depends critically on IDT. An additional amplification polymer layer is added to the SAW sensor's design to increase the sensor's sensitivity. Nanomaterials can enhance the device's functionality. To examine the sensor, Finite Element Modeling (FEM) is performed. The sensor's performance in relation to frequency is analyzed for deflection, electric potential, hydrogen gas, and noise. IDTs are made of copper, aluminum, and gold. Copper performs better than the other materials in terms of operating frequency at a minimum IDT height. The sensor's operating frequency is 355 MHz, and its displacement is 10 nm. With copper having the largest displacement and aluminum having the lowest displacement, the sensor's operating frequency remains constant for all materials. The sensor demonstrates a good agreement between the simulated operating frequency and the theoretical operating frequency. Hydrogen gas is also tested on the sensor at concentrations ranging from 1 ppm to 100 ppm. The sensor's reaction to the concentration of hydrogen has been linear. Calculations are made regarding the sensor's group velocity and phase delay. Group velocity and power spectral density are metrics that are used to express the phase noise of the sensor

Keywords

: SAW sensor, Deflection Analysis, Nanomaterials, Mass loading, White phase Noise, Flicker phase Noise