Experimental Study Of MHD Drive Based On Ionic Liquids

Ionic liquid is a new type of fluid material with no apparent vapor pressure, wide electrochemical window, high ionic conductivity and low volatility characteristics. Most of the ionic liquid’s research and application are mainly concentrated in the field of chemical at internal and abroad, it’s physical application have been rarely studied. In fact, the ionic liquid is a good electro-optical medium that can be used in microfluidics technology, but few studies have reported it. This paper proposes the ionic liquids used in microfluidics, microfludic drive technology is the key of microfludics technology, and is also the bottleneck in microfludic applications.This paper proposes ionic liquids as a fluid medium in microfluidics, using magnetohydrodynamic(MHD) drive technology, driving fluid based on the principle of conductive liquid generated Lorentz force in the electromagnetic field, and through experiment to research the MHD drive technology based on ionic liquids. Firstly, it analyzes the physical properties of ionic liquids, and studys the MHD driving theory of ionic liquids based on the magnetic fluid dynamics. Then numerical simulation ionic liquid driving to obtain the distribution of the flow field with the finite volume method(FVM). On the basis of theoretical analysis and simulation,two experimental devices were designed for measuring ionic liquid flow rate and differential pressure.By comparison of theoretical data and simulation results, found Poiseuille theory is not very suitable for MHD-driven research. Use [bmim]BF4 ionic liquids to study the effect of water on ionic liquids MHD drive, and found traces of water can be improved MHD driving force, but will produce bubbles. Finally though [bmim]BF4 and [bmim]NTf2 ionic liquid compared with Na Cl electrolyte experiment analysis, verify the reliability and the feasibility method based on ionic liquids of the MHD drive.Moreover, experimental results show that 3ml of [bmim]NTf2 ionic liquid has good stability in a steady magnetic field of 0.4 T, under 15 Vdc voltage, the vertical driving pressure differential is 3.2 mm. The flow rates are 2.7 and 7.8 μl/s at applied direct-current potentials of 6 and 8 V, in a 0.4-T magnetic field. And ionic liquids in microfluidic delivery particles have certain advantages.The MHD drive based on ionic liquids has the advantages of simple structure,low driving voltage, large driving force and has good stability,etc. MHD drive may be applied in micro-total analysis systems, particle transporting, microfluidic/optofluidic switches, and soon. Besides driving fluid, MHD drive method can immediately change the flow direction and pattern by controlling the local electrical fields within microchannels.The experimental study of MHD driven technology based on ionic liquids can promote ionic liquids to be applied in Microfluidics.