Study on micro-dynamics in the micro-fluidic devises

Micro-PIV系统和Micro-LIF系统已被开发并应用于Micro-TAS(全分析系统)、芯片实验室等微流体领域。要制造出有效的射流装置，需要了解流场信息。在Micro-LIF系统中，利用显微镜和荧光染料清晰地显示了微通道内的pH分布。通过对pH值分布的分析，清楚地显示了微流控装置混合过程中扩散的非线性增强。在Micro-PIV系统中，采用了带像增强器的超分辨率高速摄像机，利用连续激光和显微镜对微流控系统中的微流场进行了可视化。图像分辨率为1024x1024像素，每秒2000帧。该通道的尺寸只有100微米。利用X型…实现油水逆流流动更多频道。在微通道内的油水界面处，非定常微涡清晰可见。这种现象以前从未报道过。由于高速摄像机具有高时间分辨率和高空间分辨率，因此可以实现微通道内的这种瞬变流场。所发现的微涡可能会影响界面上的非线性扩散或非线性混合，因此我们开发了Micro-PIV/LIF系统来分析微流体装置的微观动力学。测量结果清楚地表明，界面处存在非线性流动动力学。众所周知，由于微尺度的存在，界面作用力在微流控装置中起着非常重要的作用。非线性界面现象导致了非线性扩散、微涡等非线性流场的产生。微流控装置中非线性动力学的发现对于理解微流控系统的流动特性具有重要意义。此外，所开发的Micro-PIV/LIF系统也将成为研究微观动力学的有力工具。较少

The micro-PIV system and the micro-LIF system had been developed and applied to the micro-fluidics, such as the Micro-TAS (Total Analysis System), Lab-on-chip, and so on. It is very important to know the field information to fabricate the effective fluidic devises. The velocity field and the pH fields are quantitatively measured using the developed systems.In the Micro-LIF system, the pH distributions inside the micro-channel had been clearly visualized using the microscope and fluorescent dye. With analyzing the pH distributions, the non-linear enhancement of diffusions are clearly shown for the mixing process of micro-fluidic devises.In the Micro-PIV system, the super-resolution high-speed camera with Image Intensifier had been applied to visualize the micro flow using the CW laser and microscope. The resolution of the images is 1024x1024 pixel with 2000 frame per second. The size of the channel is only 100micro-m. Counter current flow with oil and water are realized using the X-type … More channel. At the interface of the oil and water inside the micro-channel, the unsteady micro-vortex is clearly visualized. This phenomenon has never reported before. Because of the high-temporal-resolution of the high-speed camera with high-spatial-resolution can realize such kind of transient flow field inside the micro-channel. The discovered micro-vortex may affect on the non-linear diffusion or non-linear mixing at the interface.We have developed the micro-PIV/LIF system to analyze the micro-dynamics of the micro-fluidic devises. The measured results clearly indicate the existence of non-linear flow dynamics at the interface. It is well-known that the interfacial forces plays most important role under the micro-fluidic devises, because of the micro-scale. The non-linear interfacial phenomena cause the non-linear flow fields, such as, non-linear diffusion and micro-vortex. The discovery of the non-linear dynamics in the micro-fluidic devises is very important to understand the micro-flow dynamics. Also, the developed micro-PIV/LIF systems will be strong tools to investigate the micro-dynamics. Less