Microfluidic QCM enables ultrahigh Q-factor: a new paradigm for in-liquid gravimetric sensing
Year: 2024
Type: article
Abstract: Acoustic gravimetric biosensors attract attention due to their simplicity, robustness, and low cost. However, a prevailing challenge in these sensors is dissipation which manifests in a low quality factor (Q-factor), which limits their sensitivity and accuracy. To mitigate dissipation of acoustic sensors in liquid environments we introduce an innovative approach in which we combine microfluidic channels with gravimetric sensors. To implement this novel paradigm we chose the quartz crystal microbalance (QCM) as our model system, owing to its wide applicability in biosensing and the relevance of its operating principles to other types of acoustic sensors. We postulate that the crucial determinant for enhancing performance lies in the ratio between the wavelength of the pressure wave generated by the oscillating channel side walls (driven by the QCM), and the width of the microfluidic channels. Our hypothesis is supported by finite element analysis (FEA) and dimensional studies, which revealed two key factors that affect device performance: 1) the ratio of the pressure wavelength to the channel width (𝜆𝑝/𝑊) and 2) the ratio of the shear evanescent wavelength to the channel height (𝜆𝑠/𝐻). To validate our hypothesis, we fabricated a microfluidic QCM (μ-QCM) and demonstrate a remarkable 10-fold improvement in its dissipation when compared to conventional QCM. The novel microfluidic approach offers several additional advantages, such as direct data interpretation, reduced volume requirement for sample liquids, and simplified temperature control, augmenting the sensor's overall performance. By fostering increased sensitivity, accuracy, and ease of operation, our novel paradigm unlocks new possibilities for advancing gravimetric biosensing technologies.
Source: Microsystems & Nanoengineering
Authors: Yicheng Zhao, Zehra Parlak, Wenjun Yu, Daniel French, Wilkins Aquino, Stefan Zauscher
Institution: Duke University
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,290
Awards: MICROCAPILLARY QUARTZ SENSORS FOR SCREENING INJECTABILITY OF HIGH CONCENTRATION PROTEIN FORMULATIONS, STTR Phase I: Microfluidic quartz resonator based blood plasma coagulation monitors, SBIR Phase I: High-throughput injectability screening of high concentration protein formulations by multiplexed microfluidic quartz resonators, G9000022675
OpenAlex ID: W4401892001