title: Performance optimization of high-order Lamb wave sensors based on silicon carbide substrates.
abstract: Silicon carbide (SiC), as a new type of material for substrates in micro-electromechanical system (MEMS), was given high consideration in virtue of the properties of high acoustic velocity, low loss, chemical resistance, and etc. In this work, five performance parameters, which are electromechanical coupling coefficients, mass sensitivities, conductivity sensitivities, insert losses and minimum detectable masses, are theoretically investigated in Lamb wave chemical sensors for gas sensing based on SiC substrates. It is presented that higher performance can be achieved based on high-order modes other than fundamental modes, and the abovementioned five parameters can be simultaneously optimized. Then, according to the optimized operating conditions, operating parameters of the SiC-based high-order Lamb wave sensors are designed, which can be easily realized in MEMS technology. Finally, it is demonstrates that the SiC-based sensor exhibits better performance than that of the sensor with a conventional silicon substrate.
authors.affiliation: Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093, PR China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093, PR China. Electronic address: FanLi@nju.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Fan
authors.affiliation: Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093, PR China.
authors.forename: Shu-yi
authors.initials: SY
authors.lastname: Zhang
authors.affiliation: Lab of Modern Acoustics, Institute of Acoustics, Nanjing University, Nanjing 210093, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
keywords: High-order Lamb wave; Silicon carbide; Ultrasonic sensors