Heat and mass transfer reduced order modeling approach of droplet microreactor based Lab-on-a-Chip devices

The paper presents a novel reduced order model, which enables the heat and mass transfer analysis of microchannels consisting of continuously moving microdroplets with enzymatic reactions inside. Due to the low Reynolds number, which is typical in microfluidic applications, the hydrodynamics can be described as Taylor-flow. The reduced order model contains the main features of Taylor-flow such as microcirculation and back flow. These are needed to achieve an accurate model of the convective heat and mass transfer. The model has been validated by a standard CFD simulation for two cases: firstly, for a purely thermal problem with constant heat flux through the wall; secondly, for an enzymatic reaction with multi-component diffusion. The results show that in the first case the model yields results with around 5% error. In the second case the error is less than 10%. The accuracy was tested for a wide range of Reynolds numbers. With this novel approach the temperature profile on the channel wall can be calculated in a few hours compared to conventional numerical techniques which would require weeks.