Study on SAW Methane Sensor Based on Cryptophane-A Composite Film

Abstract

Surface Acoustic Wave (SAW) methane-sensing technology is a new way to detect methane at room temperature. However, the material and structure of the sensitive film are the important factors affecting the detection performance of the sensor. In this paper—with a SAW methane sensor using graphene–nickel cavitation—a composite film is proposed, which can work at room temperature. A delay linear dual-channel differential oscillator with center frequency of 204.3 MHz and insertion loss of −5.658 dB was designed; Cryptophane-A material was prepared by the “three-step method”. The composite sensitive film was synthesized by a drop coating method, electrochemical deposition method and electroplating method. The composite film was characterized by SEM. The sensor performance test system and gas sensitivity test system were constructed to determine the response performance of the sensor at concentrations of 0~5% CH4. The results showed that the sensor had a good response recovery performance in the test concentration range, and the frequency offset was positively correlated with methane concentration. The 90% average response time and recovery times were 41.2 s and 57 s, respectively. The sensor sensitivity was 809.4 ± 6.93 Hz/(1% CH4). This study provides a good theoretical basis for the development of surface acoustic-wave methane sensors.

The Use of Polyurethane Composites with Sensing Polymers as New Coating Materials for Surface Acoustic Wave-Based Chemical Sensors—Part II: Polyurethane Composites with Polylaurylmetacrylate, Polyisobutene, and Poly(chlorotrifluoroethylene-co-vinylidene Fluoride): Coating Results, Relative Sensor Responses and Adhesion Analysis

“…After the initial use of pristine polymers as the sole sensing materials, many studies have been conducted looking to explore other properties of polymers than just their function as the chemical environment for the sensitization, providing different ways of support in composites with diverse types of materials, enhancing their properties, and giving rise to new types of composite sensing materials for the SAW technology [25][26][27][28][29][30].…”

Development and Validation of an ANN-Based Approach for Temperature-Dependent Equivalent Circuit Modeling of SAW Resonators

“…Today, SAW technology is used in a wide range of electronic devices and systems, such as 5G wireless communication systems, internet of things (IoT) devices, and wearable technology [ 9 , 10 , 11 ]. Additionally, the advancements in the technology have opened up new possibilities for SAW technology, such as in the field of sensing applications [ 7 , 11 , 12 , 13 , 14 ].…”

“…The high stability, high quality factor (Q-factor), and low power consumption of SAW devices make them particularly attractive for use in sensing applications. They can be used to develop a wide range of sensors, including temperature, pressure, and chemical sensors [ 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. These sensors are based on the principle of measuring the change in the SAW device resonant frequency caused by changes in the physical quantity being measured.…”

“…These sensors are based on the principle of measuring the change in the SAW device resonant frequency caused by changes in the physical quantity being measured. For example, chemical sensors based on SAW devices have been developed for the detection of a wide range of chemical compounds, including gases, liquids, and biomolecules [ 11 , 12 , 14 , 18 , 19 ]. They are very attractive because of their high sensitivity and selectivity, as well as their ability to operate in harsh environments.…”