Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345E, DK-2800 Kgs. Lyngby, Denmark.
Sensors (Basel). 2013 Dec 23;14(1):229-44. doi: 10.3390/s140100229.
For devices such as bio-/chemical sensors in microfluidic systems, flow fluctuations result in noise in the sensor output. Here, we demonstrate in-line monitoring of flow fluctuations with a cantilever-like sensor integrated in a microfluidic channel. The cantilevers are fabricated in different materials (SU-8 and SiN) and with different thicknesses. The integration of arrays of holes with different hole size and number of holes allows the modification of device sensitivity, theoretical detection limit and measurement range. For an average flow in the microliter range, the cantilever deflection is directly proportional to the flow rate fluctuations in the microfluidic channel. The SiN cantilevers show a detection limit below 1 nL/min and the thinnest SU-8 cantilevers a detection limit below 5 nL/min. Finally, the sensor is applied for in-line monitoring of flow fluctuations generated by external pumps connected to the microfluidic system.
对于微流系统中的生物/化学传感器等设备，流动波动会导致传感器输出中的噪声。在这里，我们展示了一种通过集成在微流道中的类似悬臂的传感器对流动波动进行在线监测的方法。悬臂由不同的材料（SU-8 和 SiN）和不同的厚度制成。不同孔径和孔数的孔阵列的集成允许对器件灵敏度、理论检测限和测量范围进行修改。对于微升范围内的平均流量，悬臂的挠度与微流道中的流量波动成正比。SiN 悬臂的检测限低于 1 nL/min，最薄的 SU-8 悬臂的检测限低于 5 nL/min。最后，该传感器用于在线监测连接到微流系统的外部泵产生的流动波动。
