A Fluidic Interface with High Flow Uniformity for Reusable Large Area Resonant Biosensors

Abstract

Resonant biosensors are known for their high accuracy and high level of miniaturization. However, their fabrication costs prevent them from being used as disposable sensors and their effective commercial success will depend on their ability to be reused repeatedly. Accordingly, all the parts of the sensor in contact with the fluid need to tolerate the regenerative process which uses different chemicals (H3PO4, H2SO4 based baths) without degrading the characteristics of the sensor. In this paper, we propose a fluidic interface that can meet these requirements, and control the liquid flow uniformity at the surface of the vibrating area. We study different inlet and outlet channel configurations, estimating their performance using numerical simulations based on finite element method (FEM). The interfaces were fabricated using wet chemical etching on Si, which has all the desirable characteristics for a reusable biosensor circuit. Using a glass cover, we could observe the circulation of liquid near the active surface, and by using micro-particle image velocimetry (μPIV) on large surface area we could verify experimentally the effectiveness of the different designs and compare with simulation results.

Regenerable ZnO/GaAs Bulk Acoustic Wave Biosensor for Detection of Escherichia coli in “Complex” Biological Medium

“…The compatibility of this material with many chemical functionalization approaches and surface micro/nanofabrication processes makes it an ideal candidate for a biosensor application [ 23 , 24 ]. The surface of GaAs can be chemically functionalized with alkanethiols [ 25 , 26 , 27 , 28 ], silanes and phosphonates [ 29 ], and can be relatively easily regenerated [ 30 , 31 ], which gives this material very attractive functionalities for the fabrication of antibody-based architectures. Furthermore, it has been reported that an enhanced piezoelectric response of the GaAs-based acoustic sensor could be achieved upon deposition of a thin film of ZnO [ 32 , 33 , 34 ].…”

Theoretical study and finite element simulation of ZnO/GaAs higher-order Lamb waves for microsensor application in liquid media

“…Gallium Arsenide (GaAs) is a unique material due to its piezoelectric and optical properties for potential application of acoustic [5] and photonic sensor [9] integrated into the same substrate. GaAs biosensor can be integrated with a microfluidic channel by direct bonding process [10]. However, the piezoelectricity of GaAs is relatively smaller compared to those commonly used piezoelectric materials.…”

Multidisciplinary Role of Microfluidics for Biomedical and Diagnostic Applications: Biomedical Microfluidic Devices

“…This special issue of Micromachines entitled ‘Biomedical Microfluidic Devices’ provides a discussion of the technical challenges associated with developing microfluidic devices for biomedical and diagnostic applications. Addressing these challenges requires technological advances in many areas, including sensors [ 1 , 2 ], actuators [ 3 ], materials [ 4 , 5 ], microfabrication techniques [ 6 ], simulations and models [ 7 , 8 , 9 ], and platform technologies [ 10 , 11 , 12 ]. This special issue consists of 12 high-quality papers, including two insightful review articles [ 4 , 12 ].…”

“…A rigorous analysis and optimization of flow through such devices can be achieved using computational fluid dynamic (CFD) analysis. For example, Azzopardi et al [ 7 ] improved the uniformity of flow across a large-area resonant biosensor by using COMSOL multiphysics. By using ANSYS Fluent, Li et al [ 8 ] optimized microfluidic microfilters of circulating tumor cells to achieve higher throughput, less cellular damage, and better efficiency.…”

“…For example, Tsai’s group [ 10 , 11 ] developed a pressure-driven microfluidic constriction platform to evaluate on-chip red blood cell deformability. In general, according to a distinct set of fluidic manipulation processes, biomedical microfluidic devices can be categorized into different microfluidic platforms, for example, capillary-driven, pressure-driven [ 7 , 8 , 9 , 10 , 11 ], vacuum-driven, electrowetting-driven, centrifugal-driven [ 3 ], droplet-based [ 4 ], and paper-based microfluidic platforms, among others. An article by Basha et al [ 12 ] provides a comprehensive review of the core processes implemented in POC devices (e.g., lysis techniques, nucleic acid extraction, amplification of specific DNA/RNA, and genomic identification methods) and microfluidic platforms suitable for molecular diagnosis (e.g., paper-based, centrifugal-based, and electrowetting-based microfluidic platforms).…”