Chemical sensor based on surface acoustic wave resonator using Langmuir-Blodgett film

Abstract

A one-port surface acoustic wave (SAW) resonators incorporating Langmuir-Blodgett (LB) films has been investigated. SAW sensors are one potential applications of SAW devices. Most of the work reported on SAW sensor concerns delay lines. In this paper we characterize the mass loading effects of one-port resonators by depositing successive monolayers of LB films onto the surface. A 90 MHz SAW gas-phase sensor has been fabricated on an ST cut quartz substrate, and one-port resonator configurations have been used as the sensing element. Ultra thin monolayers of arachidic acid and arachidic acid ethyl ester have been deposited using the LB method. The resonant frequencies and the Q values have been measured as sensor response. Experimental results show that the Q values and the resonant frequencies of the one-port SAW resonator vary with film mass loading on the SAW device surface.

Langmuir Film Polymerization of 1,22-Bis(2-aminophenyl)docosane: A Two-Dimensional Cross-linked Polyalkylaniline

“…Ultrathin films have been proposed for many applications such as in nonlinear optical − and electroluminescent devices , and sensors. , However, most applications require the films to be mechanically, thermally, and chemically stable under environmental conditions, which is often difficult to achieve. Polymeric systems are usually more stable than low molar mass analogues due to covalent bonding in the film plane and are often preferred …”

Microelectromechanical Systems and Devices

“…Other emerging applications of SAW resonators include gas sensors (Sadek et al, 2006), biosensors (Z. Xu, 2009), chemical (Nomura et al, 1998), temperature and pressure sensors (Buff et al, 1997). The significance of these devices in this industry can be measured in numbers by the worldwide production of these devices, where approximately 3 billion acoustic wave filters are used annually, primarily in mobile cell phones and stations (Reindl et al, 1996).…”

A Y type SAW mass sensor with metal array reflectors

“…SAW sensors have many merits, so they have wide applications, such as gas sensor, biosensor, humidity sensor and so on [1]. These devices can be categorized into multiplefrequency device [2]; dual path device [3]; resonator device [4] and so on. However, the SAW and bulk wave propagate in the same direction in these devices.…”