【摘要】 在电动微流体粒子图像测速技术中,示踪粒子的电泳运动是影响测量不确定度的主要因素之一.采用电流方法和粒子图像跟踪技术相结合,测量流体的平均电渗淌度和示踪粒子运动淌度,计算粒子的电泳淌度,据此对显微粒子图像测速结果进行修正.实验测量了直径为520 nm的聚苯乙烯示踪粒子在20 mm o l/L硼砂缓冲液中的电泳淌度,对水力直径小于20μm的锥形微管道M icro-P IV测量流场进行了修正.实验结果表明,修正后的流场速度与数值计算结果一致,该方法可以较好地消除示踪粒子电泳运动对M icro-P IV测量结果的影响.更多还原

【Abstract】 When the micro particle image velocimetry(Micro-PIV) is used to investigate the characteristics of electrokinetic-driven fluidic flow,the electrophoretic mobility of the micro particles primarily contributes to the uncertainty,which must be considered.The strategy to eliminate this systemic error has been proposed.In this strategy,the current velocimetry method was used to measure the electroosmotic mobility of the fluid,and the particle tracking velocimetry(PTV) was used to measure the locomotory mobility of the particles.The particle′s electrophoretic mobility was obtained.Then the fluidic velocity profile was corrected by the estimated particle′s electrophoretic mobility.The electrophoretic mobility of the polystyrene seeds with diameter of 520 nm in 20 mmol/L borax buffer solution has been measured by the proposed method.The electroosmotic fluidic velocity in cone shape microchannel with hydraulic diameter of less than 20 μm has been obtained.The experiments indicate that the compensated velocity field is consistent with the computed results by home-made computer fluid dynamics software.The systemic errors due to the charges on the surface of particles have been eliminated.更多还原