Rodrigues Tomás, Galindo-Rosales Francisco J, Campo-Deaño Laura
CEFT, Departamento de Engenharia Mecânica, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
CEFT, Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
Materials (Basel). 2019 Apr 2;12(7):1086. doi: 10.3390/ma12071086.
Measuring fluid pressure in microchannels is difficult and constitutes a challenge to even the most experienced of experimentalists. Currently, to the best of the authors' knowledge, no optimal solution are being used for the design of pressure taps, nor guidelines concerning their shape and its relation with the accuracy of the readings. In an attempt to address this issue, a parametric study was devised to evaluate the performance of different pressure tap designs, 18 in total. These were obtained by combining three shape parameters: sub-channel width () and sub-channel-tap radius () or angle (α), while having the sub-channel length kept constant. For each configuration, pressure drop measurements were carried out along several lengths of a straight microfluidic rectangular channel and later compared to an analytical solution. The microchannels were fabricated out of PDMS using standard soft-lithography techniques, pressure drop was measured with differential pressure sensors, the test fluid was DI water and the flow conditions varied from creeping flow up to R e c ∼100. Pressure taps, having smooth contours (characterised by the radius ) and a sub-channel width () of 108 μ m , performed the best with results from that of radius R = 50 μ m only falling short of the theory by a mere ∼ 5 % .
在微通道中测量流体压力十分困难，即使是经验最丰富的实验人员也会面临挑战。目前，据作者所知，在压力传感器的设计中尚未采用最佳解决方案，也没有关于其形状及其与读数准确性关系的指导原则。为了解决这个问题，我们设计了一项参数研究，以评估总共18种不同压力传感器设计的性能。这些设计是通过组合三个形状参数获得的：子通道宽度（）和子通道-传感器半径（）或角度（α），同时保持子通道长度不变。对于每种配置，沿着直的微流体矩形通道的几个长度进行压降测量，然后与解析解进行比较。微通道由聚二甲基硅氧烷（PDMS）使用标准软光刻技术制造，使用差压传感器测量压降，测试流体为去离子水，流动条件从蠕动流到Re c ∼100不等。轮廓光滑（以半径表示）且子通道宽度（）为108μm的压力传感器表现最佳，半径R = 50μm的压力传感器的结果仅比理论值低约5%。
