A novel langasite crystal microbalance instrumentation for UV sensing application

Self Cite

We propose a novel langasite crystal microbalance (LCM) sensor with a graphene-based sensing medium to detect and discriminate volatile organic compounds (VOCs) at room temperature. A thin film of graphene oxide embedded with Pt nanostructures (GO-Pt nanocomposite) was deposited on the electrode surface of the LCM, a thickness-shear acoustic wave resonator. Ethyl acetate, acetic acid, and ethanol were chosen as typical VOCs for this study. Sensitivity and selectivity of coated LCM were investigated for different concentrations of the VOCs by analysing the resonant properties of the sensor. When exposed to VOCs, a negative shift in series resonance frequency was observed due to the mass loading of VOC molecules. Simultaneously, changes in equivalent resistance and parallel resonance frequency of the sensor were also observed due to the interaction of VOCs with charge carriers on the GO-Pt nanocomposite film surface. This dual measurement of both series and parallel resonance frequencies allowed for detection and discrimination of VOCs. Moreover, the high thermal stability of langasite makes the proposed sensor suitable even for harsh environmental conditions.

Section: Selectivitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Langasite Crystal Microbalance Coated with Graphene Oxide-Platinum Nanocomposite as a Volatile Organic Compound Sensor: Detection and Discrimination Characteristics

Leong

Saha

Swamy

et al. 2020

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“…Several piezoelectric crystals exhibiting high phase-transition temperatures are used for microbalance applications, mainly, the

( GCM ) and more recently, the langasite (LCM) crystals [ 59 , 125 , 126 ]. GCM sensors exhibit irreversible phase-transition around

, compared to

for LCM resonators [ 59 ].…”

Section: High Temperature Applications Design Considerationsmentioning

confidence: 99%

Quartz Crystal Microbalance Electronic Interfacing Systems: A Review

Alassi

Benammar

Brett

2017

150

Quartz Crystal Microbalance (QCM) sensors are actively being implemented in various fields due to their compatibility with different operating conditions in gaseous/liquid mediums for a wide range of measurements. This trend has been matched by the parallel advancement in tailored electronic interfacing systems for QCM sensors. That is, selecting the appropriate electronic circuit is vital for accurate sensor measurements. Many techniques were developed over time to cover the expanding measurement requirements (e.g., accommodating highly-damping environments). This paper presents a comprehensive review of the various existing QCM electronic interfacing systems. Namely, impedance-based analysis, oscillators (conventional and lock-in based techniques), exponential decay methods and the emerging phase-mass based characterization. The aforementioned methods are discussed in detail and qualitatively compared in terms of their performance for various applications. In addition, some theoretical improvements and recommendations are introduced for adequate systems implementation. Finally, specific design considerations of high-temperature microbalance systems (e.g., GaPO 4 crystals (GCM) and Langasite crystals (LCM)) are introduced, while assessing their overall system performance, stability and quality compared to conventional low-temperature applications.

“…One of the options for creating UV radiation sensors is the use of a combination of ZnO and resonant sensors based on bulk acoustic waves (QCM, quartz crystal microbalance; LCM, La 3 Ga 5 SiO 14 langasite crystal microbalance). In [ 26 ], such a UV radiation sensor was implemented, in which the LCM was used. A ZnO film was formed on the LCM surface by magnetron sputtering.…”

Section: Introductionmentioning

confidence: 99%

Ultraviolet Radiation Sensor Based on ZnO Nanorods/La3Ga5SiO14 Microbalance

Рощупкин

Редькин

Емелин

et al. 2021

The possibility of creating resonant ultraviolet (UV) sensors based on the structure of ZnO nanorods/La3Ga5SiO14 microbalance (LCM) has been investigated. The principle of sensor operation is based on the desorption of oxygen from the surface of ZnO nanorods upon irradiation with UV light and an increase in the concentration of charge carriers that leads to an increase in the capacitance of the structure of ZnO nanorods/LCM. It has been shown that UV radiation intensity affects the resonance oscillation frequency of the LCM sensor. After the end of irradiation, the reverse process of oxygen adsorption on the surface of ZnO nanorods occurs, and the resonance frequency of the sensor oscillations returns to the initial value.