Physics of Fluids Group and MESA+ Institute of Nanotechnology, P.O. Box 217, 7500 AE Enschede, The Netherlands.
Lab Chip. 2014 May 21;14(10):1705-14. doi: 10.1039/c3lc51296g. Epub 2014 Mar 20.
An ultrasound contrast agent (UCA) suspension contains encapsulated microbubbles with a wide size distribution, with radii ranging from 1 to 10 μm. Medical transducers typically operate at a single frequency, therefore only a small selection of bubbles will resonate to the driving ultrasound pulse. Thus, the sensitivity can be improved by narrowing down the size distribution. Here, we present a simple lab-on-a-chip method to sort the population of microbubbles on-chip using a traveling ultrasound wave. First, we explore the physical parameter space of acoustic bubble sorting using well-defined bubble sizes formed in a flow-focusing device, then we demonstrate successful acoustic sorting of a commercial UCA. This novel sorting strategy may lead to an overall improvement of the sensitivity of contrast ultrasound by more than 10 dB.
超声造影剂（UCA）悬浮液含有封装的微泡，其具有较宽的尺寸分布，半径范围从 1 到 10 微米。医疗换能器通常在单个频率下工作，因此只有一小部分微泡会对驱动超声脉冲产生共振。因此，通过缩小尺寸分布可以提高灵敏度。在这里，我们提出了一种简单的片上实验室方法，使用行波在片上对微泡进行分选。首先，我们使用在流聚焦装置中形成的具有明确定义尺寸的微泡来探索声泡分选的物理参数空间，然后我们成功地对商业 UCA 进行了声分选。这种新颖的分选策略可能会使对比超声的灵敏度整体提高超过 10dB。
