Modelling and Simulation using Finite Element Method of Surface Acoustic Wave Biosensor for Gas Detection Application

Abstract A surface acoustic wave (SAW) sensor detects changes in physical properties such as mass and density on its surface. Compared to other types of sensors, SAW sensor have a good stability, high selectivity and sensitivity, fast response, and low-cost. On the other hand, to design and optimize a SAW biosensor requires a long process including time and cost using conventional methods. Therefore, numerical simulation and computational modelling are useful and efficiently conduct analysis for the SAW biosensor. In this paper, a numerical simulation technique is used to analyse the SAW device sensitivity for the application of gas detection. The SAW biosensor can detect very small mass loading by changing its sensor resonance frequency. The two-dimensional (2D) device model is based on a two-port SAW resonator with a gas sensing layer. We made two design of SAW biosensor device with frequency of 872 MHz and 1.74 GHz. A gas with vary concentration from 1 to 100 ppm were used to determine the change of the device resonance frequency. As a result, the high frequency (1.74 GHz) device, shows that the resonance frequency is shifted larger than to the low frequency (872 MHz) device. In addition, the high frequency device offers five times more sensitivity than the low frequency device. By changing the sensor design, the sensor characteristics such as sensitivity can be altered to meet certain sensing requirements. Numerical simulation provides advantages for sensor optimization and useful for nearly representing the real condition.

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Passive Impedance-Loaded Surface Acoustic Wave (SAW) Sensor for Soil Condition Monitoring

Volume 13: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2020-23746 ◽

2020 ◽

Author(s):

Jian Chu ◽

Ioana Voiculescu ◽

Ziqian Dong ◽

Fang Li

Keyword(s):

Acoustic Wave ◽

Surface Acoustic Wave ◽

Condition Monitoring ◽

Low Cost ◽

Soil Condition ◽

Nutrient Sensing ◽

Soil Conditions ◽

Large Area ◽

Saw Sensor ◽

Loaded Surface

Abstract This paper presents an innovative system to monitor the physical soil conditions needed for modern agriculture. The current technique to measure soil properties relies on taking samples from place to place and takes them for laboratory testing. To build up and monitor a data-based system for a large area, such a method is costly and time-consuming. This paper reported our recent work on the development of a passive impedance-loaded surface acoustic wave (SAW) sensor for a low-cost soil condition monitoring system. The SAW sensor will eventually be connected to an antenna and a impedance-based sensor for autonomous soil nutrient sensing. In this research, first, the coupling-of-modes (COM) analysis was performed to simulate the SAW device. The sensors were fabricated with E-beam lithography techniques and tested with different external load resistances. We investigated how the sensor signal changed with the external resistance loading. The experimental results were verified by comparing them with simulation results.

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Wireless passive surface acoustic wave (SAW) technology in gas sensing

Sensor Review ◽

10.1108/sr-03-2020-0061 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Yong Pan ◽

Qin Molin ◽

Tengxiao Guo ◽

Lin Zhang ◽

Bingqing Cao ◽

...

Keyword(s):

Acoustic Wave ◽

Gas Sensor ◽

Surface Acoustic Wave ◽

Potential Application ◽

Gas Sensing ◽

Development Trend ◽

Gas Detection ◽

Content Type ◽

Research Status ◽

Saw Sensor

Purpose This paper aims to give an overview about the state of wireless passive surface acoustic wave (SAW) gas sensor used in the detection of chemical vapor. It also discusses a variety of different architectures including delay line and array sensor for gas detection, and it is considered that this technology has a good application prospect. Design/methodology/approach The authors state the most of the wireless passive SAW methods used in gas sensing, such as CO2, CO, CH4, C2H4, NH3, NO2, et al., the sensor principles, design procedures and technological issues are discussed in detail; their advantages and disadvantages are also summarized. In conclusion, it gives a prospect of wireless passive SAW sensor applications and proposes the future research field might lie in the studying of many kinds of harmful gases. Findings In this paper, the authors will try to cover most of the important methods used in gas sensing and their recent developments. Although wireless passive SAW sensors have been used successfully in harsh environments for the monitoring of temperature or pressure, the using in chemical gases are seldom reported. This review paper gives a survey of the present state of wireless passive SAW sensor in gas detection and suggests new and exciting perspectives of wireless passive SAW gas sensor technology. Research limitations/implications The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted. Originality/value The authors will review most of the methods used in wireless passive SAW sensor and discuss the current research status and development trend; the potential application in future is also forecasted.

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FEM Modeling of the Temperature Influence on the Performance of SAW Sensors Operating at GigaHertz Frequency Range and at High Temperature Up to 500 °C

Sensors ◽

10.3390/s20154166 ◽

2020 ◽

Vol 20 (15) ◽

pp. 4166

Author(s):

Jean Claude Asseko Ondo ◽

Eloi Jean Jacques Blampain ◽

Gaston N’Tchayi Mbourou ◽

Stephan Mc Murtry ◽

Sami Hage-Ali ◽

...

Keyword(s):

High Temperature ◽

Acoustic Wave ◽

Resonance Frequency ◽

Surface Acoustic Wave ◽

Full Range ◽

Frequency Variation ◽

Fem Modeling ◽

Saw Sensor ◽

Sensing Applications ◽

Numerical Predictions

In this work, we present a two-dimensional Finite Element Method (2D-FEM) model implemented on a commercial software, COMSOL Multiphysics, that is used to predict the high temperature behavior of surface acoustic wave sensors based on layered structures. The model was validated by using a comparative study between experimental and simulated results. Here, surface acoustic wave (SAW) sensors consist in one-port synchronous resonators, based on the Pt/AlN/Sapphire structure and operating in the 2.45-GHz Industrial, scientific and medical (ISM) band. Experimental characterizations were carried out using a specific probe station that can perform calibrated measurements from room temperature to 500 °C. In our model, we consider a pre-validated set of physical constants of AlN and Sapphire and we take into account the existence of propagation losses in the studied structure. Our results show a very good agreement between the simulation and experiments in the full range of investigated temperatures, and for all key parameters of the SAW sensor such as insertion losses, resonance frequency, electromechanical factor of the structure (k2) and quality factor (Q). Our study shows that k2 increases with the temperature, while Q decreases. The resonance frequency variation with temperature shows a good linearity, which is very useful for temperature sensing applications. The measured value of the temperature coefficient of frequency (TCF) is equal to −38.6 ppm/°C, which is consistent with the numerical predictions.

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The Designation and Simulation of Amplifying and Shaping Circuit of SAW Gas Sensor Signal

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1030-1032.1348 ◽

2014 ◽

Vol 1030-1032 ◽

pp. 1348-1351

Author(s):

Xiao Tao Bai ◽

Tao Zhang ◽

Qiang Liu ◽

Bei Bei Zhang

Keyword(s):

Acoustic Wave ◽

Gas Sensor ◽

Surface Acoustic Wave ◽

High Frequency ◽

Small Amplitude ◽

Detection Method ◽

Gas Detection ◽

Sensor Signal

In this paper, a kind of amplifying and shaping circuit was designed according to the characteristics of high frequency and small amplitude of surface acoustic wave (SAW) gas sensor signal. The circuit is applied to two-channel mixing detection method to solve the problem that backend devices cannot identify sensor signal. The whole circuit is simple in structure and has very good shaping effect on voltages signal of millivolt level, meeting the need of the sensor of gas detection.

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