CAREER: Investigation of bubble dynamics in microscale geometries, with applications in bioengineering and microfluidics

职业：研究微观几何形状中的气泡动力学，及其在生物工程和微流体学中的应用

• 批准号: 0449269
• 负责人: Daniel Attinger
• 金额: $ 40万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2006-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0449269&HistoricalAwards=false
• 关键词: CAREER; Investigation; bubble; dynamics; microscale

ABSTRACT 0449269Investigation of bubble dynamics in microscale geometries, with applications in bioengineering and microfluidics Dynamics phenomena involving microbubbles are aesthetic, complex, and important in industrial applications such as bubble-jet printing. If the dynamics of a bubble in an unbounded liquid is well understood, a lot a basic scientific work needs to be done to understand the dynamics of a bubble in contact with a solid surface, in a bounded microscale geometry. This problem of fundamental and practical interest will be addressed through two research initiatives. The first initiative concerns the dynamic motion of a bubble in a microchannel. The channel geometry, and the dynamic wetting at the gas-liquid-wall interface, control the pressure needed to move the bubble in the channel. This issue is critical in microfluidics devices, where bubbles can clog microchannels with narrow restrictions. This problem will be studied theoretically and experimentally with a MEMS-based setup and high-speed visualization. The second initiative studies how a microbubble attached to a solid surface reacts to ultrasound. Recent investigations have shown that ultrasound drives bubbles oscillations, which produce a tiny, donut-shape vortex in the vicinity of the bubble, a phenomenon called microstreaming. Our theoretical and experimental research will involve simulations of microstreaming in the presence of solid boundaries and Particle-Image-Velocimetry (PIV). This microstreaming field and the associated shear stress will be used to deform biological cells and bring drugs through their membranes, as well as to build a microengine. A general-purpose micro- PIV system will be acquired for this research, with a camera that also allows high-speed imaging. The intellectual merit is the development of a science base for the dynamic behavior of microbubbles in contact with a solid geometry. This first study on the motion of a bubble in a microchannel will be supported on the theoretical side by a collaboration with Henrik Bruus.s research group in Denmark, and on the experimental side (nanocoatings) with Oleg Gang, from the Center for Functional Nanomaterials at Brookhaven National Laboratory. Significant advances are expected on the understanding of the motion of the wetting angle, its hysteresis and relaxation time scale. Our second study will investigate how microstreaming depends on the bubble wetting angle and the nearby solid surfaces. Theoretical and experimental investigations will be performed, involving (for the theoretical side) coupled solid-fluid interactions acoustic calculations, simulations of acoustic microstreaming in the presence of solid boundaries, and (for the experimental side) high-speed visualization together with micro Particle Image Velocimetry. This second study involve collaboration with Dr. Citovski.s biology group at Stony Brook, as well as Dr. Moraga from the Center for Multiphase Research at Rensselaer Polytechnic Institute. The broader impact will be the development in collaborations with Seyonic SA and Micronics Inc- of more reliable microfluidic devices, solving the issue of undesired bubbles through self-cleaning channel geometries or bubble traps. Also, novel ways to interact with biological cells through microstreaming will be investigated, with the development of a novel sonoporation device to control drug transfection through cell membranes and manipulate them. The microstreaming flow field will also be used to power a novel type of microengine that fits in a human hair, to be developed in collaboration with Oleg Gang, from the Center for Functional Nanomaterials at Brookhaven National Laboratory. Finally, we are convinced that visualization of bubble-related phenomena provide an attractive path from everyday experience to current scientific challenges involving micro- and nanoscale phenomena. This will be used to interest local high school and elementary school students from the Bronx to engineering, and to generate interest for research in the Stony Brook student community.

摘要0449269微尺度几何结构中气泡动力学的研究，在生物工程和微流体中的应用涉及微气泡的动力学现象在工业应用中是美学的、复杂的和重要的，例如气泡喷射打印。如果我们很好地理解了无限液体中气泡的动力学，那么就需要做大量的基础科学工作来理解在有界微尺度几何中气泡与固体表面接触的动力学。这一具有根本和实际意义的问题将通过两项研究举措加以解决。 第一个倡议涉及微通道中气泡的动态运动。 通道的几何形状，以及在气-液-壁界面处的动态润湿，控制在通道中移动气泡所需的压力。这个问题在微流体装置中是关键的，其中气泡可以阻塞具有狭窄限制的微通道。这个问题将在理论和实验上进行研究，基于MEMS的设置和高速可视化。第二项计划研究附着在固体表面上的微泡如何对超声波作出反应。最近的研究表明，超声波驱动气泡振荡，在气泡附近产生微小的环形涡流，这种现象称为微流。 我们的理论和实验研究将涉及在固体边界和粒子图像测速（PIV）的存在下的微流模拟。这种微流场和相关的剪切应力将用于使生物细胞变形，并使药物穿过它们的膜，以及建立一个微引擎。 一个通用的微型PIV系统将获得这项研究，与相机，也允许高速成像。智力的价值是发展的科学基础的动态行为的微泡接触的固体几何形状。 这是第一项关于微通道中气泡运动的研究，将在理论方面得到与丹麦的Henrik Bruus研究小组的合作支持，在实验方面（纳米涂层）与布鲁克海文国家实验室功能纳米材料中心的Oleg Gang合作。对润湿角的运动、滞后和弛豫时间尺度的理解有望取得重大进展。 我们的第二个研究将探讨如何微流依赖于气泡润湿角和附近的固体表面。将进行理论和实验研究，包括（理论方面）耦合固体-流体相互作用声学计算，在固体边界存在下的声学微流模拟，以及（实验方面）高速可视化与微粒子图像测速。第二项研究涉及与斯托尼布鲁克的西托夫斯基博士的生物学小组以及伦斯勒理工学院多相研究中心的莫拉加博士的合作。 更广泛的影响将是与Seyonic SA和Anchorics Inc合作开发更可靠的微流体设备，通过自清洁通道几何形状或气泡捕获器解决不需要的气泡问题。此外，将研究通过微流与生物细胞相互作用的新方法，开发一种新的声致孔装置来控制药物通过细胞膜的转染并对其进行操作。微流场还将用于为一种适合人类头发的新型微发动机提供动力，该发动机将与布鲁克海文国家实验室功能纳米材料中心的Oleg Gang合作开发。最后，我们相信，气泡相关现象的可视化提供了一个有吸引力的路径，从日常经验到当前的科学挑战，涉及微观和纳米级的现象。这将被用来感兴趣的当地高中和小学学生从布朗克斯工程，并产生兴趣的研究在斯托尼布鲁克学生社区。