Holographic Micro Flow Meter for Biological Sensing

有没有被超速摄像头拍到过？大多数工作通过采取两个图像在快速连续的速度计算你的车从分离的图像。我们已经发明了一种类似的技术，用于测量微米大小的物体在流体中移动的速度。我们的技术依赖于光镊，紧密聚焦的光束来捕获和保持流体中的微小尺寸的测试颗粒。反复脉冲镊子将物体释放到流体流中，并且在颗粒被重新捕获之前，速度相机记录它们的速度。许多测量的结果被平均，以给出流体流动的速度，精度为每秒一微米。我们将应用我们的技术的一个领域是微流体，微米级的流体通道网络，允许转移和混合化学试剂，探针或生物物体。这种系统是“芯片实验室”技术的基础，比全尺寸的实验室同类产品更便宜、更紧凑、更快。实验室芯片的小规模意味着流体行为是非直观的，水流更像混凝土，因此测量流体的能力既优雅又有指导意义。除了了解微流体流动，我们的目标是将该技术应用于各种生物应用。细胞周围的流体流动产生机械应力，用不了解的参数修改细胞反应;运动细胞可以在流体中游泳，但同样，流体流动的产生和感知之间的相互作用知之甚少。我们相信，我们测量流体流动的能力与空间和时间分辨率相结合，我们在其他成像和传感技术方面的专业知识将使我们能够解决这些问题和许多其他有趣的问题。

Ever been caught by a speed camera? Most work by taking two images in quick succession the speed of your car being calculated from the separation of its images. We have invented a similar technique for measuring the speed of micron sized objects moving within a fluid. Our technique relies on optical tweezers, tightly focussed beam of light to trap and hold micro-sized test particles in the fluid. Pulsing the tweezers repeated releases the objects into the fluid flow and the speed camera records their velocity, before the particles are re trapped. The result of many measurements is averaged to give the velocity of the fluid flow to an accuracy of one micron per second. One area where we will apply our technique is micro-fluidics, micron-sized networks of fluid channels allowing the transfer and mixing of chemical reagents, probes or bio-objects. Such systems are the basis of 'lab on chip' technology, cheaper, more compact and faster than their full sized lab equivalents. The small scale of lab chips means that fluid behaviour is non-intuitive, water flow being more like concrete, hence the ability to measure the fluid is both elegant and instructive. Beyond gaining an understanding of micro-fluidic flow, our aim is to apply the technique to various bio-applications. Fluid flow around a cell creates mechanical stress, modifying the cell response with a parameter that is not understood; motile cells can swim in a fluid, but again the interplay between the creation and sensing of fluid flow is poorly understood. We believe that our ability to measure the fluid flow with both spatial and temporal resolution combined with our proven expertise in other imaging and sensing technologies will allow us to address these and many other interesting issues.