scholarly journals Mass Sensitivity Analysis of a Newly Developed Quartz Crystal Microbalance with Ring-Dot Electrode Configuration and Reduced Mass Loading Area

2021 ◽  
Vol 4 (1) ◽  
pp. 32
Author(s):  
Siddharth Swaminathan ◽  
Arezoo Emadi
Keyword(s):  
Resonant Frequency ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Quartz Substrate ◽  
Ring Electrode ◽  
Electrode Configuration ◽  
Mass Loading ◽  
Element Analysis ◽  
Mass Sensitivity ◽  
Sensitivity Distribution

Quartz Crystal Microbalance (QCM) is used for detecting microgram level mass changes in gas and liquid phase. Conventional QCM design comprises a circular electrode configuration with an evenly distributed mass loading area. However, their mass sensitivity distribution is found to be non-uniform due to the inherent energy trapping effect. In this paper, the recently developed QCM with a ring electrode and a ring-dot electrode configuration are evaluated. It is shown that this new configuration offers the ability to achieve a uniform mass sensitivity distribution, while attaining a comparable mass sensitivity for a reduced mass loading area. Finite Element Analysis is used to design and evaluate the conventional circular electrode QCM, and the proposed ring electrode and ring-dot electrode QCM configurations, where the mass loading area is reduced by 25% compared with the conventional sensor. Simulations are conducted to determine the sensor’s resonant frequency shifts for an added mass per unit area of 20 μg/mm2. The results indicate that newly designed ring and ring-dot electrode configurations operate at a higher resonant frequency. The observed frequency shift for the designed circular electrode, ring electrode, and ring-dot electrode configurations on a 333 μm thick quartz substrate are 85 kHz, 84 kHz, and 82 kHz, respectively. It is shown that the ring electrode and new ring-dot electrode configurations achieve a higher resonant frequency and offer a comparable sensing performance despite comprising of over 25% reduced mass loading area, in comparison to the conventional circular electrode configuration.

Analysis and Improvement of the Mass Sensitivity for Piezoelectric Immunosensor

2013 ◽  
Vol 378 ◽  
pp. 435-439
Author(s):  
Yan Chen ◽  
Xian He Huang ◽  
Hua Shan Shi ◽  
Hong Chen
Keyword(s):  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Amplitude Equation ◽  
Maximum Mass ◽  
Vibration Displacement ◽  
Mass Sensitivity ◽  
Surface Electrodes ◽  
Sensitivity Distribution ◽  
Piezoelectric Immunosensor ◽  
Thickness Shear

The objective of this study was to improve the low repeatability in quartz crystal microbalance (QCM) measurements. The constitutive equations for the thickness-shear vibrations of an AT-cut quartz crystal with surface electrodes were used to obtain the particle vibration displacement amplitude equation. Then the mass sensitivity of piezoelectric immunosensor was analyzed and the approach to improve low repeatability was proposed. A 10MHz modified-electrode AT-cut QCM with a maximum mass sensitivity of was designed to verify uniform mass sensitivity distribution in the fully electrode region. Analysis results show that in order to improve the accuracy in QCM immunosensor measurements, it is feasible to improve its mass sensitivity.

scholarly journals A Real-Time Method for Improving Stability of Monolithic Quartz Crystal Microbalance Operating under Harsh Environmental Conditions

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4166
Author(s):  
Román Fernández ◽  
María Calero ◽  
Yolanda Jiménez ◽  
Antonio Arnau
Keyword(s):  
Real Time ◽  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Limit Of Detection ◽  
Quartz Substrate ◽  
Low Cost ◽  
Discrete Wavelet ◽  
Reagent Consumption ◽  
Measurement Cell ◽  
The Stability

Monolithic quartz crystal microbalance (MQCM) has recently emerged as a very promising technology suitable for biosensing applications. These devices consist of an array of miniaturized QCM sensors integrated within the same quartz substrate capable of detecting multiple target analytes simultaneously. Their relevant benefits include high throughput, low cost per sensor unit, low sample/reagent consumption and fast sensing response. Despite the great potential of MQCM, unwanted environmental factors (e.g., temperature, humidity, vibrations, or pressure) and perturbations intrinsic to the sensor setup (e.g., mechanical stress exerted by the measurement cell or electronic noise of the characterization system) can affect sensor stability, masking the signal of interest and degrading the limit of detection (LoD). Here, we present a method based on the discrete wavelet transform (DWT) to improve the stability of the resonance frequency and dissipation signals in real time. The method takes advantage of the similarity among the noise patterns of the resonators integrated in an MQCM device to mitigate disturbing factors that impact on sensor response. Performance of the method is validated by studying the adsorption of proteins (neutravidin and biotinylated albumin) under external controlled factors (temperature and pressure/flow rate) that simulate unwanted disturbances.

scholarly journals The Role of Wettability on the Response of a Quartz Crystal Microbalance Loaded with a Sessile Droplet

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Brandon Murray ◽  
Shankar Narayanan
Keyword(s):  
Contact Angle ◽  
Frequency Response ◽  
Quartz Crystal Microbalance ◽  
Contact Area ◽  
Quartz Crystal ◽  
Quartz Substrate ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Decay Length ◽  
Sessile Droplet

AbstractIn this work, the interaction between a sessile droplet’s contact angle and a quartz crystal microbalance (QCM) is elucidated. We differentiate the QCM’s frequency response to changes in the droplet contact area from variations in the dynamic contact angle. This is done by developing a computational model that couples the electrical and mechanical analysis of the quartz substrate with the visco-acoustic behavior of the sessile droplet. From our analysis, we conclude that changes in the contact angle have an effect on the frequency response of the QCM when the droplet height is on the order of the viscous decay length or smaller. On the other hand, changes in the interfacial contact area of the sessile droplets have a significant impact on the frequency response of the QCM regardless of the droplet size.

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