Verification of Quartz Crystal Microbalance Array using Vector Network Analyzer and OpenQCM

Abstract

<p>Quartz Crystal Microbalance (QCM) is a device that allows non-destructive measurements of r in situ reaction activities. In this article, an array comprising of six 3MHz QCM sensors in an array were characterized using a vector network analyzer and OpenQCM, a portable measuring instrument that measures change in resonance frequency. Measurements of S21 transmission characteristics using the vector network analyzer provides the resonance frequency and can also be used to derive the RLC equivalent electrical circuit values of a resonant two-port network based on the Butterworth-Van Dyke model. In this work, R<sub>m</sub>, L<sub>m</sub>, C<sub>m</sub> and C<sub>o </sub>were obtained via curve-fitting of the measurement results to the simulated results. Measurements were done in triplicates to verify reproducibility for all 6 sensors. For comparison, measurements were also done using a portable, open-source instrument, OpenQCM. The OpenQCM instrument directly measures changes in resonance frequencies, making it ideal for biosensing experiments, which correlate changes in mass with changes in resonance frequencies. Comparison between resonance frequency measurements using VNA and OpenQCM exhibit low percentage difference 0.2%. This QCM sensor array has the potential of conducting real-time, point-of-care analyses for detection of biological molecules. </p>

Advances in Analysis of Milk Proteases Activity at Surfaces and in a Volume by Acoustic Methods

“…In this circuit, the C 0 is the static electrical capacitance. Due to the piezoelectric properties of the quartz, the electromechanical coupling resulted in additional motional elements L, C and R m [ 41 ]. The parameters of this circuit can be determined by a network analyzer, as is schematically presented in Figure 4 .…”

Integrated Multichannel Electrochemical–Quartz Crystal Microbalance Sensors for Liquid Sensing

“…The novelty of this improved work with respect to our previous ones [14]- [17] lies in the experimental verification of both the QCM and integrated electrochemical sensor. Our previous work concentrated on the modeling and resonance measurements of the QCM and no experimental measurements on the integrated electrochemical sensor had been done.…”

“…ρ, η and µ is the density, viscosity and shear modulus with indices l, f , and q indicating the liquid, film (electrode), and quartz respectively. All the material properties used in this work have been detailed in [17].…”

Modeling and development of radio frequency planar interdigital electrode sensors

“…Next, the theoretical evaluation of another parameter, Q was done. The Quality factor or Q factor of electrical components and devices is a measure of the relationship between stored energy and the rate of energy use, giving an indication of their efficiency [10]. The basic Q or quality factor equation is based upon the energy losses within the inductor, circuit or other form of component.…”