Enhancing Capillary Force in Glass Microfluidics Devices for Bioengineering Applications

Abstract

Microfluidic devices have been grown dramatically in recent years. They are widely used in the different fields like biomedicine, cell manipulation, inkjet print heads, molecular biology and DNA analysis. The most important advantages of microfluidic devices are low energy consumption, high precision, low time and low cost. These benefits depend on the performance of fluid motion in microchannels. The major disadvantage of microchannels fabricated on glass or silicon is lack of surface wettability. The fabricated microchannels on glass and silicon substrates cannot transfer water based fluids by surface tension force and usually an external pump is needed to provide enough force to push the fluid along the micro channel. Most of the bio research and applications related to microfluidic devices are working on bio materials which are soluble in water. For bio applications usually it is essential to fabricate hydrophil microstructures while silicon and glass are not hydrophil. Silicon and glass are the most important substrates which are used for MEMS and microfluidic fabrication. In this paper nano rods are proposed to cover micro channel internal surface in order to enhance hydrophilicity of microfluidic structure. COMSOL is considered as simulation software which is used for simulating fluid motion in microchannels. For evaluation of simulated structure, a star microfluidic structure is fabricated on glass substrate and fluid movement in channels is investigated by experimental setup. The simulated and experimental results show that fabrication of TiO2 nano rod on internal surface of microchannels would increase capillary force.