MHD Microfluidic Drive And Optical Apparatuses

Microfluidics, ‘Lab on a chip’ is a emerging interdiscipline. It is combined with Optics to emerge a new discipline, namely, optofluidics. The key technologys of microfluidics/optofluidics include the fluid drive, selection on fluids, and design and fabrication of apparatuses. The driving technology is often a bottleneck in the microfluidic applications. Furthermore, the research on optofluidic apparatuses is still at an early stage, and microscale liquids are often volatilized.Here ionic liquids are proposed for microfluidics or optofluidics. A magnetohydrodynamics(MHD) drive based on ionic liquids is researched by using hydrophilic and hydrophobic ionic liquids. The study results show that MHD drive is fit for ionic liquids, and the 2~3 ml ionic liquid can flow continuously driven by only several volts and 0.4 or 0.5 T electromagnetic field. Moreover ionic liquids are found to have some advantages in microfluidic applications through the comparison with electrolytes. By comparing the experimental results with the theoretical data, the limitation of Poiseuille’s law is pointed for MHD drive. In addition, the DC conductivity of ionic liquids is measured and researched in order to make the theory agreed with the experiment. The experiments show that the ionic liquids can be vibrated by the pulse current and the static magnetic field. The conducted research is aimed at finding a simple, low voltages and low cost drive technique and promoting the application of ionic liquids in microfluidics or optofluidics.In order to measure some ionic liquids with large refractive index, a refractometer based on liquid prism is designed and its working principle are given. ZEMAX, a software for optical design, is used to design this refractometer, and the relevant experiments are done. This refractometer has more simple structure, lower cost and wider measuring range than Abbe Refractometer, and is easily transformed into the product. The nuclear structure of a microfluidic variable optical attenuator(VOA) is presented. Based on this nuclear structure, three VOAs based on different drive techniques are designed. Meanwhile this kind of the VOA is researched by theory simulation. The VOA has a large attenuation range, small insertion loss and large return loss. The researched VOA can offer a new way to look for new small, integrated, adjustable and good property optical communication apparatuses.