Binding reaction kinetics of analyte-ligand at the level of a sensitive membrane into a microchannel of a biosensor has been limited by the formation of the boundary diffusion layer. Therefore, the response time increases and affects the overall performance of a biosensor. In the present work, we develop an approach to engineer fluid streams into a complex configuration in order to improve the binding efficiency. We investigate numerically the flow deformations around a parallelepiped with square cross-section inside the microfluidic channel and exploit these deformations to simulate the analyte transport to the sensitive membrane and enhance both association and dissociation processes. The effect of several parameters on the binding reaction is provided such as: the obstacle location from the inlet of the microchannel, the average flow velocity, and the inlet analyte concentration. The optimal position of the obstacle is determined. An appropriate choice of the inlet flow velocity and inlet analyte concentration may reduce significantly the response time.

Microwave ablation is one type of hyperthermia treatment of cancer that involves heating tumor cells. This technique uses electromagnetic wave effects to kill cancer cells. A micro-coaxial antenna is introduced into the biological tissue. The radiation emitted by the antenna is absorbed by the tissue and leads to the heating of cancer cells. The diffuse increase in temperature should reach a certain value to achieve the treatment of cancer cells but it should be less than a certain other value to avoid damaging normal cells. This is why hyperthermia treatment should be carefully monitored. A numerical simulation is useful and may provide valuable information. The bio-heat equation and Maxwell’s equations are solved using the finite element method. Electro-thermal effects, temperature distribution profile, specific absorption rate (SAR), and fraction of necrotic tissue within cancer cells are analyzed. The results show that SAR and temperature distribution are strongly affected by input microwave power. High microwave power causes a high SAR value and raises the temperature above 50 °C, which may destroy healthy cells. It is revealed that with a power of 10 W, the tumor cells will be killed without damaging the surrounding tissue.

In this work, we present a numerical investigation of blood flow in a portion of the human vascular system. More precisely, the present work analyzed the blood flow in the upper portion of the aorta. The aorta and its ramified blood vessels are surrounded by the cardiac muscle. The blood flow generates pressure on the internal surfaces of the artery and its ramifications, thereby causing deformation of the cardiac muscle. The numerical analysis used the Navier–Stokes equations as the governing equations of blood flow for the calculation of the velocity field and pressure distribution in the blood. The neo-Hookean hyperelastic model was used for the description of the behavior of the vessel walls. The velocity and pressure distributions were analyzed. The deformation of the vessel was also investigated. The numerical results could be used to better understand and predict the factors that trigger cardiovascular diseases and distortions of the aorta and as a diagnostic tool in clinical applications.

A heterogeneous immunoassay is an efficient biomedical test. It aims to detect the presence of an analyte or to measure its concentration. It has many applications, such as manipulating particles and separating cancer cells from blood. The enhanced performance of immunosensors comes down to capturing more antigens with greater efficiency by antibodies in a short time. In this work, we report an efficient investigation of the effects of alternating current (AC) electrokinetic forces such as AC electroosmosis (ACEO), which arise when the fluid absorbs energy from an applied electric field, on the kinetics of the antigen–antibody binding in a flow system. The force can produce swirling structures in the fluid and, thus, improve the transport of the analyte toward the reaction surface of the immunosensor device. A numerical simulation is adequate for this purpose and may provide valuable information. The convection–diffusion phenomenon is coupled with the first-order Langmuir model. The governing equations are solved using the finite element method (FEM). The impact of AC electroosmosis on the binding reaction kinetics, the fluid flow stream modification, the analyte concentration diffusion, and the detection time of the biosensor under AC electroosmosis are analyzed.