CFD Analysis of a Microfluidics Lab-on-a-Chip Component

Abstract

The idea of a Lab-on-a-Chip is to integrate a laboratory on a small chip. This makes the Lab-on-a-Chip technology dependent on the knowledge of microfludics. The goals of this project were to model, and then analyse and calculate numerically a component inside such a microsystem. This component is the so-called capillary burst valve, which is a valve utilizing capillary effects. As this master project is a continuation of the project work done in the autumn of 2009, another goal was to continue working on the problem of capillary rise for code verification cite{Ane}. This report gives a description of relevant theory concerning capillary rise and capillary burst valves, together with a description of the CFD modelling approach for both of the problems. In the further study of capillary rise, other challenges arose in the form of mass loss. Due to this the results were varying. Some of the results were considered good despite the mass loss. Because of the good results it was concluded yet again that it is possible to simulate capillary rise. A suggestion of a new way of solving the problem of mass loss is proposed. In the conclusion of the project work from the autumn of 2009 it was assumed that simulations of the capillary burst valve are possible. Several interesting results were obtained. With the right grid, the flow development was considered to be physical even though the burst pressure for the simulations was too low. Possible reasons for the need of low pressures at the outlet were found. It was concluded that simulations of the capillary burst valve are possible as interesting results were obtained and further studies were suggested.