Numerical simulation of the microchannel for the microfluidic based flow sensor

Abstract

Microfluidic technology has given major contribution to the advancement of the sensor especially in the development of microchannel. Previously, we proposed the design structure consist of microchannel which is integrated with dome-shaped container and electrode. The underwater flow sensor generally used in aqua robotic and underwater vehicle for the monitoring and surveillance. The fluid flow gives drag force to the dome-shaped which resulting some displacement and causes the liquid inside the microchannel moving. In this paper, the performance of microchannel had been simulated and discussed in order to optimize the microchannel based on the variation of height and the selection of liquid. The computational fluid dynamic (CFD) FLUENT software was used for the simulation of microchannel. From the CFD, the velocity profile has been analyzed for under and fully develop region to study the fluid flow behavior. The velocity for variation microchannel height 300μm until 1100μm was plotted where the channel with large dimension has an advantage in order to make the fluid flow smooth. In order to achieve the small scale of sensor, we limited the channel size to 400μm. Another factor that influences the fluid flow inside the microchannel is properties of liquid. A few liquids such as methanol, ethanol, water and propylene carbonate were selected. The important property we consider in selection of the right liquid is the surface tension where is it related to the kinematic viscosity. From the simulation, we prove that the liquid that having lowest kinematic viscosity and low surface tension such as methanol is have better performance than another liquid for sensing purpose.