【作者】 于娟；

【导师】 周明；

【作者基本信息】 江苏大学 ， 材料物理与化学， 2011， 硕士

【摘要】 减小流体设备的尺寸引发了很多问题,其中之一是驱动流体流动过程中压力梯度的快速增加。在这种条件下,驱动流体流动的表面引起很多人的关注。本文从实验的角度讨论了表面性能,比如结构形貌和润湿性能在驱动流体流动过程中起着重要的作用。采用纳秒激光以线扫描方式在硅基底(典型的超亲水材料)表面加工不同形貌结构的结构表面,采用磁控溅射仪在硅基底表面溅射具有低表面能的不同材料的薄膜来改变表面的润湿性能。通过体视显微镜可以观察到红墨水溶液在制备的微槽内的流动情况。可以得到在不同的结构形貌和润湿性能的条件下,红墨水溶液沿着微槽中的流动情况。溶液在微槽中流动的距离(z)与流动时间(t)的关系服从经典的关系:z = ct1/2。随着微槽宽度和润湿性能的提高,参数c也在增加,表明溶液在微槽中流动的速度也加快。这些结果表明亲水性结构表面能为流体在其表面流动提供一定的驱动力。在微流体设备中,这种驱动力能够为流体流动提供一种有效的方法。本文主要进行了如下的工作:(1)采用纳秒激光器以线扫描的方式加工硅片,在硅片表面得到了不同宽度的微槽,研究了微槽的宽度对液体流动特性的影响。(2)采用磁控溅射的方法在加工的硅片表面镀膜,研究了不同材料的润湿性对液体流动特性的影响,得出材料的润湿性越好,液体在槽中的流动特性越好。(3)采用纳秒激光器以线扫描的方式在硅片表面加工了U形微通道,研究了U形微通道中酚酞遇碱变色的反应,得出了在微通道(或微反应器)中同样可以进行化学反应。而且在微反应器中试剂用量少,反应更容易控制。更多还原

【Abstract】 Downsizing fluidic devices raises many problems, one being the rapid increase of pressure gradient that drives the fluid flow. In this context, surface induced fluid spread has attracted increasing interest. Here, we investigate experimentally how the surface properties such as structure profiles and wetting properties play a role in driving fluid spread. The structured surfaces with different structure profiles were fabricated by using nanosecond laser in line scanning mode on the Si substrates (typical hydrophilic material) and their wetting properties were adjusted by sputter-coating different material films with low surface energy. Then the spread of the red ink solution on the as-prepared surfaces was observed by microscopy. We found that in all cases with different structure profiles and wetting properties, the red ink solution spreads along the grooves on the structured surfaces. The relation of the spreading distance of the red ink solution in these grooves (z) with the spreading time (t) is in accord with the typical relation z = ct1/2. With the increase in both the width of the grooves and the wetting properties, the parameter c increases, indicating that the red ink solution spreads in the grooves with a higher velocity. These results indicate that the structured hydrophilic surfaces can offer certain drag force for fluid over them. Such drag force may provide an effective approach for fluid flow in microfluidic devices.In this paper, we do the following work:(1) Using nanosecond laser by line scanning mode to process silicon, we obtain different widths micro-groove in silicon surfaces. We investigate the width of the microchannel having inflence on flowing characteristics of the liquid.(2) We adopt magnetron control sputtering device by sputter-coating different material films with low surface energy.of silicon in the prepared silicon surface to study the wettability of different materials inflencing on the fluid flowing characteristics, the better wettability of the material obtained, the quicker liquid flows in micro-channel.(3) Using nanosecond laser by line scanning mode to process silicon, we get U-shaped micro-channel in the silicon surface. We investigate that once phenolphthalein comes across alkaline, the phenolphthalein will become red. We can find that not only the chemical reaction can also react in the micro-channel (or micro-reactor), but also the micro-reactor is with less reagents and the reaction is more easily controlled.更多还原