Pulse mode shear horizontal-surface acoustic wave (SH-SAW) system for liquid based sensing applications

Abstract

In this work we describe a novel pulse mode shear horizontal surface acoustic wave (SH-SAW) polymer coated biosensor that monitors rapid changes in both amplitude and phase. The SH-SAW sensors were fabricated on 36 ο rotated Y-cut X propagating Lithium Tantalate (36 YX.LT). The sensitivity of the device to both mass loading and visco-elastic effects may be increased by using a thin guiding layer of cross-linked polymer. Two acoustic modes are excited by the electrodes in this crystalline direction. Metallisation of the propagation path of the 36 YX.LT devices allows the two modes to be discriminated. Successive polymer coatings resulted in the observation of resonant conditions in both modes as the layer thickness was increased.Using the 36 YX.LT devices, we have investigated the application of a novel pulse P r e -P r i n t mode system by sensing a sequence of deposition and removal of a biological layer consisting of vesicles of the phospholipid POPC. A continuous wave system was used to verify the accuracy of the pulse mode system by sensing a series of Poly(ethylene glycol) (PEG) solutions. The data clearly demonstrates the ability of the 36 YX.LT pulse mode system to provide rapid measurements of both amplitude and phase for biosensing applications.

Other Surface-Acoustic-Wave Based Instruments

“…The substrate avoids bending. The guiding layer can be thinner than bulk acoustic wave resonators, which improves the mass-sensitivity such in-plane polarized surface modes are also called shear-horizontal surface acoustic wave devices (SH-SAW devices) [33][34][35][36]. For liquid sensing, SH-SAW devices should be superior in performance to the QCM, in principle, but there are a number of problems, which have prevented such devices from becoming a commercial success, so far.…”

Study on Wireless Torque Measurement Using SAW Sensors

“…Their impact has made possible considerable reductions in size and power of the chipsets of mobile devices (Fujitsu Media Devices Ltd., 2006;Epcos AG, 2008). More modest and important applications of SAW resonators are the measurements in mass detector and pressure sensor devices with application in bio-particle detection (Martin, F., 2004;Talbi, A., 2006).…”

Tonometric biosensor with a differential pressure sensor for chemo-mechanical measurement of glucose

“…Calorimetric devices such as thermister have been also used for the measurement of the thermal change by the reaction heat (exothermal and endothermal) at those enzymatic reactions (Rajkumar et al, 2008;Ramanathan and Danielsson, 2001;Urban et al, 1991). In addition, mass changes caused by intermolecular reactions can be assessed by Quartz Crystal Microbalance (QCM) or Surface Acoustic Wave (SAW) devices (Briand et al, 2007;Fatoyinbo et al, 2007;Ogi et al, 2007;Gronewold et al, 2005;Joseph et al, 2005;Martin et al, 2004). However, a chemo-mechanical conversion device for biosensor and biological measurements has not been reported.…”