Nanostructure‐Enhanced Surface Acoustic Waves Biosensor and Its Computational Modeling

Abstract

Surface acoustic wave (SAW) devices are considered to be very promising in providing a high-performance sensing platform with wireless and remote operational capabilities. In this review, the basic principles of SAW devices and Love-mode SAW-based biosensors are discussed first to illustrate the need for surface enhancement for the active area of a SAW sensor. Then some of the recent efforts made to incorporate nanostructures into SAW sensors are summarized. After that, a computational approach to elucidate the underlying mechanism for the operations of a Love-mode SAW biosensor with nanostructured active surface is discussed. Finally, a modeling example for a Love-mode SAW sensor with skyscraper nanopillars added to in its active surface along with some selected results is presented.

Design and Fabrication of Nanoscale IDTs Using Electron Beam Technology for High‐Frequency SAW Devices

“…Piezoelectric films such as lead zirconate titanate (PZT), zinc oxide (ZnO), and aluminum nitride (AlN) thin films have been applied in acoustic devices for various applications [6][7][8][9][10][11][12][13][14][15]. In this study, the piezoelectric thin films of AlN are adopted for the applications of high-frequency SAW devices, owing to its better quality factor, high acoustic velocity, and high electromechanical coupling coefficient.…”

Design and Optimization of ZnO Nanostructured SAW-Based Ethylene Gas Sensor with Modified Electrode Orientation

“…Different pitch value of 1 µm, 1.5 µm and 2 µm are considered and it is found that 2 µm provides higher displacement of SAW at both input and output and output for a device length ranging from 8 to 20 microns. It results in enhanced sensitivity [17]. The frequency shift of the sensor is observed because of the different concentration of the target gas.…”

Nanoscale Surface Modification for Enhanced Biosensing

“…Therefore, with nanopillarmodified electrodes, the EIS measurements are more sensitive and suitable, as compared with the CV measurements, for discriminating the slight change caused by surface adsorption of MUA, avidin, and biotin. 1,2,4,6,8,10,20,30,40, and 50 ng/mL). Unlike in the bare electrode case, these CV curves are not peak-shaped, indicating that the coupling of biotin with avidin at the electrode surface has caused further reduction in electron transfer.…”

“…Bulk acoustic waves are more susceptible to liquid-damping induced attenuation than surface acoustic waves, thus detections based on bulk acoustic waves (in the cases of a double-clamped beam or a quartz crystal microbalance) are preferably used in a dry environment and detections based on surface acoustic waves are often used in a liquid environment. A detailed discussion of the applications of bulk and surface acoustic wave devices can be found in reviews by Rao and Zhang [39] and Zhang [40]. By detecting the frequency shift, the attenuation drop, and the phase shift, the amount of bound analyte can be determined.…”