Simulation and Fabrication of Higher‐Mode Lamb Wave Acoustic Devices for Sensing Applications

Abstract

Recently Lamb wave devices have originated as an alternate acoustic device for high‐frequency wireless sensing applications. Their potential for sensing devices, including biomedical diagnostics and environmental monitoring as a wireless and passive device, calls for further analysis of the device with higher sensitivity. ZnO‐based sensor has always been of research interest due to its biocompatibility, sensing abilities, and yet cost‐effectivity. A Lamb wave device based on ZnO/SiO2/Si membrane has been theoretically simulated using finite element analysis method (FEM) to study the higher modes, as higher working frequency leads to higher sensitivity of the device toward sensing applications. Optimized properties are identified and utilized for the fabrication of Lamb wave devices. It is observed that for optimized parameters of ZnO/SiO2/Si Lamb device, higher antisymmetric modes are not only advantageous for high sensitivity applications but also more stable within the given operating conditions. Experimentally obtained results indicate close matching with theoretical results.

Four-Channel Ultrasonic Sensor for Bulk Liquid and Biochemical Surface Interrogation

“…Additionally, the full control over the transmit pattern and oversampling of the received acoustic waves is often considered to be an overkill for compact and low-priced devices (as biosensors are supposed to be) since electronics for transmit wave synthesis and received wave sampling are considered pricey and energy demanding. Most of the research on acoustic biosensing is related to the development of sensing principles and is still dependent on the use of expensive laboratory equipment [15,16,[39][40][41]. In the current work, the concept of stand-alone, single-board, miniature, and low-cost electronics was demonstrated as a proof of concept for future acoustic wave biosensors, eliminating functional complexity and providing highly flexible opportunities for the biosensor user.…”