Analysis of Temperature-Jump Boundary Conditions on Heat Transfer for Heterogeneous Microfluidic Immunosensors

Abstract

The objective of the current study is to analyze numerically the effect of the temperature-jump boundary condition on heterogeneous microfluidic immunosensors under electrothermal force. A three-dimensional simulation using the finite element method on the binding reaction kinetics of C-reactive protein (CRP) was performed. The kinetic reaction rate was calculated with coupled Laplace, Navier−Stokes, energy, and mass diffusion equations. Two types of reaction surfaces were studied: one in the form of a disc surrounded by two electrodes and the other in the form of a circular ring, one electrode is located inside the ring and the other outside. The numerical results reveal that the performance of a microfluidic biosensor is enhanced by using the second design of the sensing area (circular ring) coupled with the electrothermal force. The improvement factor under the applied ac field 15 Vrms was about 1.2 for the first geometry and 3.6 for the second geometry. Furthermore, the effect of temperature jump on heat transfer rise and response time was studied. The effect of two crucial parameters, viz. Knudsen number (Kn) and thermal accommodation coefficient (σT) with and without electrothermal effect, were analyzed for the two configurations.

Numerical simulation and optimization of AC electrothermal microfluidic biosensor for COVID-19 detection through Taguchi method and artificial network

“…In order to improve the sensitivity of microfluidic chips, many numerical and experimental studies have been made [ 18 , 19 ]. Magnetic effect [ 20 ], optical forces [ 21 ], electrokinetic effect [ 22 – 27 ], etc., are physical mechanisms that have been applied to agitate the flows in the microchannel to improve the rate of the biosensor binding reaction. Several studies [ 28 , 29 ] have analyzed the effect of the reaction surface and electrodes shapes for a biosensor excited by an electrothermal force in order to improve the topology of the flow and thus decrease the detection time compared to the same biosensor having a rectangular binding surface.…”

Numerical optimization of microfluidic biosensor detection time for the SARS-CoV-2 using the Taguchi method

“…In this case, the reaction is said to be transport limited and it generally causes the formation of a diffusion boundary layer which reduces the performance of microfluidic biosensors [14]. To enhance the analyte transport, several experimental and numerical approaches have been developed [15][16][17][18][19][20][21][22][23][24][25]. Analytes and ligands immobilized binding reaction on the sensitive surface lead to the formation of analyte-ligand complexes on this surface, the concentration of which has a determining role for the detection process [19,26].…”