scholarly journals NH3-Sensing Mechanism Using Surface Acoustic Wave Sensor with AlO(OH) Film

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1732
Author(s):  
Xiaofeng Xu ◽  
Xiaotao Zu ◽  
Dongyi Ao ◽  
Jingxia Yu ◽  
Xia Xiang ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
High Performance ◽  
Positive Response ◽  
Sol Gel ◽  
Mesoporous Structure ◽  
Sensing Mechanism ◽  
Saw Sensor ◽  
Loading Effects ◽  
Elastic Loading

In this study, AlO(OH) (boehmite) film was deposited onto a surface acoustic wave (SAW) resonator using a combined sol-gel and spin-coating technology, and prepared and used as a sensitive layer for a high-performance ammonia sensor. The prepared AlO(OH) film has a mesoporous structure and a good affinity to NH3 (ammonia gas) molecules, and thus can selectively adsorb and react with NH3. When exposed to ammonia gases, the SAW sensor shows an initial positive response of the frequency shift, and then a slight decrease of the frequency responses. The sensing mechanism of the NH3 sensor is based on the competition between mass-loading and elastic-loading effects. The sensor operated at room temperature shows a positive response of 1540 Hz to 10 ppm NH3, with excellent sensitivity, selectivity and stability.

A high sensitivity wireless mass-loading surface acoustic wave DNA biosensor

2014 ◽  
Vol 28 (07) ◽  
pp. 1450056 ◽  
Author(s):  
Hua-Lin Cai ◽  
Yi Yang ◽  
Yi-Han Zhang ◽  
Chang-Jian Zhou ◽  
Cang-Ran Guo ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Dna Sequences ◽  
Biological Treatment ◽  
High Performance ◽  
Processing System ◽  
High Sensitivity ◽  
Treatment Method ◽  
Saw Sensor ◽  
Target Dna

In this paper, a surface acoustic wave (SAW) biosensor with gold delay area on LiNbO 3 substrate detecting DNA sequences is proposed. By well-designed device parameters of the SAW sensor, it achieves a high performance for highly sensitive detection of target DNA. In addition, an effective biological treatment method for DNA immobilization and abundant experimental verification of the sensing effect have made it a reliable device in DNA detection. The loading mass of the probe and target DNA sequences is obtained from the frequency shifts, which are big enough in this work due to an effective biological treatment. The experimental results show that the biosensor has a high sensitivity of 1.2 pg/ml/Hz and high selectivity characteristic is also verified by the few responses of other substances. In combination with wireless transceiver, we develop a wireless receiving and processing system that can directly display the detection results.

Development of ball surface acoustic wave gas chromatograph for environmental monitoring in spacecraft and its application on the ground

2022 ◽  
Author(s):  
Takamitsu Iwaya ◽  
Shingo Akao ◽  
Kazushi Yamanaka ◽  
Tatsuhiro Okano ◽  
Nobuo Takeda ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Stationary Phases ◽  
Micro Electro Mechanical System ◽  
Steel Plates ◽  
Gas Chromatograph ◽  
Site Analysis ◽  
Saw Sensor ◽  
Ball Surface ◽  
Brewing Process

Abstract For on-site analysis of surface materials on the moon, planets, and small bodies and for the monitoring of air quality in crewed spacecraft, we have developed a portable gas chromatograph (GC) equipped with a ball surface acoustic wave (SAW) sensor. In this study, we fabricated a 10 cm cube GC that implements the forward flush method using two metal micro-electro-mechanical-system (MEMS) columns coated with different stationary phases in microchannels fabricated by wet etching and diffusion bonding of stainless-steel plates. Using this GC, we succeeded in analyzing 10 kinds of gas within 10 min. In addition, for the application of the ball SAW GC on the ground, we also developed a palm-sized GC with a single metal capillary column and used it in the analysis of the headspace gas of sake. We showed that the ratio of peak areas differed among odorants depending on the brand and brewing process of sake.

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