Biomicrofluidics. 2009 Dec 1;3(4):44111. doi: 10.1063/1.3270523.
Nanoparticle image velocimetry (nano-PIV), based on total internal reflection fluorescent microscopy, is very useful to investigate fluid flows within approximately 100 nm from a surface; but so far it has only been applied to flow over smooth surfaces. Here we show that it can also be applied to flow over a topologically structured surface, provided that the surface structures can be carefully configured not to disrupt the evanescent-wave illumination. We apply nano-PIV to quantify the flow velocity distribution over a polydimethylsiloxane surface, with a periodic gratinglike structure (with 215 nm height and 2 mum period) fabricated using our customized multilevel lithography method. The measured tracer displacement data are in good agreement with the computed theoretical values. These results demonstrate new possibilities to study the interactions between fluid flow and topologically structured surfaces.
基于全内反射荧光显微镜的纳米粒子图像测速法（nano-PIV）对于研究距离表面约 100nm 范围内的流体流动非常有用；但迄今为止，它仅被应用于平滑表面上的流动。本文中，我们证明了只要表面结构能够被仔细配置以不破坏消逝波照明，它也可以应用于拓扑结构表面上的流动。我们应用 nano-PIV 来量化聚二甲基硅氧烷表面上的流动速度分布，该表面具有周期性的光栅状结构（高度为 215nm，周期为 2µm），采用我们定制的多级光刻方法制造。测量的示踪剂位移数据与计算的理论值吻合较好。这些结果展示了研究流体流动与拓扑结构表面之间相互作用的新可能性。
