Surface Bound Adsorption in a Microfiuidic T-Sensor: Numerical Comparison and Optimization of 2D and 3D Models

摘要

We compare models in two and three spatial dimensions for describing the interplay of convection, diffusion and adsorption in a microfiuidic T-sensor. A distinct section of the channel wall is functionalized with surface bound receptors in order to detect specific molecules from the buffer solution. The geometric shape of this section shall later be optimized with respect to a favorable sensor signal over wide ranges of solute concentrations. However, model-based approaches for solving this inverse problem in 3D would require tremendous computational effort. We have hence simplified the model by eliminating the channel height coordinate. In the 2D model, vertical diffusion of solute molecules is accounted for by a stagnant film over the sensor surface. This contribution addresses how to adjust the flow profile, film mass transfer resistance, and thickness of the stagnant film in the 2D model in order to best approximate the sensor load of the 3D model.