We design, fabricate and experimentally demonstrate a novel generic method to detect flow rates and precise changes of flow velocity in microfluidic devices. Using our method we can measure flow rates of ∼2 mm/s with a resolution of 0.08 mm/s. The operation principle is based on the Doppler shifting of light diffracted from a self-generated periodic array of bubbles within the channel and using self-heterodyne detection to analyze the diffracted light. As such, the device is appealing for variety of “lab on chip” bio-applications where a simple and accurate speed measurement is needed, e.g., for flow-cytometry and cell sorting.
展开▼
机译：我们设计，制造和实验演示了一种新颖的通用方法来检测微流体装置中的流速和流速的精确变化。使用我们的方法，我们可以测量约2 mm / s的流速，分辨率为0.08 mm / s。该操作原理基于从通道内自生气泡周期性生成的阵列衍射的光的多普勒频移，并使用自外差检测来分析衍射光。因此，该设备吸引了需要简单而准确的速度测量（例如流式细胞术和细胞分选）的各种“芯片实验室”生物应用。
展开▼
