MEMS Acoustic Tweezers for Micromanipulation of Living Cells

摘要 这项研究是为了开发基于菲涅耳透镜的可以捕捉和操纵生物的超声波镊子。 按需在三维(3D)空间中的组织，非常类似于光学镊子，但具有几个数量级 对于给定的温度升高，机械捕捉力大小更大。由校长领导的实验室 研究人员(PI)最近展示了超声波捕获液体中的微粒(直径70-400微米) 具有单个多焦点菲涅尔传感器(MFT)。捕获的微粒按要求由 在3D模式下移动MFT本身。在这一成功的基础上，这项提议将推动传感器技术的发展 单个MFT可以根据需要通过电信号捕获和移动3D粒子或细胞，而不需要 需要移动传感器。这将使广泛的生物研究人员受益，包括那些在 分子生物学、发育生物学和细胞生物学。 生物测试实验将用于重点和验证技术开发。我们的第一个特别节目 超声波镊子的应用将是捕获和保持对于激光捕获来说太大的活标本(例如， 斑马鱼胚胎和癌症衍生的球体)使用MFT。这些被困住的多细胞结构将是 保持无机械接触，用于时间推移显微镜，并将被声波镊子扭曲以 测试改变的物理力量对胚胎和器官发育的影响。这些实验需要 诱捕和钳制的力量大到足以改变胚胎的形状(远远大于 可以使用光学镊子)。 我们将在3D空间开发捕获位置的电气可控性，以便捕获的标本 可以：(1)从一个位置移动到另一个位置，(2)拉伸或压缩以表征 细胞的弹性性质；(3)与其他细胞或含基因脂质体接触。这些都将是 在电子指令下执行，不需要机械地移动超声波镊子。 为了优化超声波镊子作为生物实验工具的发展，有两个 生物实验室(由合作研究人员领导)将从一开始就参与研究。他们将收到 4年内6、18、30、42个月末的连续版本声学镊子 研究期间，并将使用它们进行拟议的转基因胚胎、细胞实验 球体和非贴壁的循环细胞。拟议中的生物实验需要操纵活体 细胞在液体环境中，不会因握持装置造成任何损害。这种无接触的操作 如果没有拟议的镊子，将是极其困难的，如果不是不可能的话。这两个生物实验室将 积极参与镊子的协同推进，进行生物实验； 提供及时的反馈，指导PI的实验室创造最有用的设计。 由于MFT将声能聚焦在一个非常小的点上，并能够通过 作为一种中间固体，它可以被结合到各种微流控平台中用于细胞管理， 液体、微粒和蛋白质。MFT对诱捕位置和方向的电气可控性 力，加上MFT形成阵列的顺应性，将允许创建复杂的 高通量的生化分析和/或生物医学治疗。MFT史无前例的 对(直径数十-数百微米)微粒/细胞的3D捕获和按需操作将 在细胞研究、基因导入、并列和操作方面开辟了许多新的可能性。

Abstract This research is to develop Fresnel-lens-based ultrasonic tweezers that can capture and manipulate living tissue in three dimensional (3D) space on demand, very much like optical tweezers but with several orders of magnitude stronger mechanical trapping force for a given temperature rise. The lab led by the Principal Investigator (PI) recently demonstrated ultrasonic capture of microparticles (70 - 400 µm in diameter) in liquid with a single Multi-foci Fresnel Transducer (MFT). The captured microparticle was moved on demand by moving the MFT itself in 3D. Building on this success, this proposal will advance the transducer technology so that a single MFT can capture and move particles or cells in 3D on demand with an electrical signal without the need to move the transducer. This will benefit a wide range of biological researchers including those in molecular, developmental and cellular biology. Biological test experiments will be used to focus and validate the technology development. Our first specific application of the ultrasonic tweezers will be to trap and hold living specimens too large for laser-trapping (e.g., zebrafish embryos and cancer-derived spheroids) using a MFT. These trapped multi-cellular structures will be held free from mechanical contact for time-lapse microscopy, and will be distorted by the acoustic tweezers to test the effects of altered physical forces on embryo and organoid development. These experiments require trapping and tweezing forces large enough to change the shape of the embryo (far greater than the forces possible with optical tweezers). We will develop electrical controllability of the trapping location in 3D space so that the captured specimens may be: (1) moved from one location to another, (2) stretched or compressed for the characterization of the cell's elastic properties, (3) brought into contact with other cells or gene-containing liposomes. These will all be performed under electrical command without the need to move the ultrasonic tweezers mechanically. To optimize the development of ultrasonic tweezers as an enabling tool for biological experiments, two biological labs (led by the co-Investigators) will participate in the research from the start. They will receive successive versions of acoustic tweezers at the ends of the 6th, 18th, 30th, and 42nd month during the 4-year research period, and will use them to conduct the proposed experiments with transgenic embryos, cell spheroids and non-adherent circulating cells. The proposed biological experiments require manipulation of live cells in a liquid environment without any damage caused by the holding device. Such contact-free manipulation would be extremely difficult, if not impossible, without the proposed tweezers. The two biology labs will participate actively in a synergistic advancement of the tweezers, performing the biological experiments, and providing timely feedbacks, directing the PI's lab towards creating the most useful designs. Since MFT focuses acoustic energy on a very small spot and is capable of delivering acoustic energy through an intermediate solid, it can be incorporated into various microfluidic platforms for the management of cells, liquids, particles and proteins. The MFT's electrical controllability on the location and direction of the trapping force, combined with amenability of MFT being formed into an array, will allow the creation of complex biochemical assays and/or biomedical treatments at high throughput. The MFT's unprecedented capability of 3D capture and on-demand manipulation of microparticles/cells (of tens - hundreds of microns in diameter) will open up many new possibilities in cell study, gene transfection, juxtaposition and manipulation.