Micro-Instrumentation for Optical Manipulation of Biological Cells with Fine Orientation Control and Low Optical Intensity

该奖项是为了开发一种名为“光等离子体镊子”的新仪器，用于生物细胞的光学操作，具有精细的方向控制和低光强要求。用光对生物细胞进行无创操作是基础生物学研究的重要手段。光等离子体镊子使用偏振光激发局部表面等离子体共振，该共振由金属纳米粒子阵列上的振荡电偶极子集合组成。这些偶极子的方向与光的偏振方向平行。它们产生一个图案辐射电场，通过介电泳相互作用操纵细胞，方向控制依赖于光的偏振。由于辐射场的高梯度，可以实现低光强。作为迈向微型仪器的第一步，微机械极化控制器也将被制造出来。微偏振控制器有望达到亚毫秒级的响应时间，从而实现对生物细胞的快速旋转控制。这是一种利用光对单个生物细胞进行无创操作的新仪器。这种能力在生物学研究和应用中具有重要意义。该技术的一个主要优点是它能够通过改变光的偏振方向以高分辨率旋转细胞，这是大多数光学操作方法无法实现的。这种能力为构建结构化生物材料在构建生物膜和人体组织工程中的潜在应用打开了大门。该仪器还将使用微加工技术进行小型化，使其占地面积小，成本低。该项目的成功将为光学操作在生物学研究中的应用开辟新的方向。这个项目也会给学生提供做跨学科研究的宝贵经验。

This award is for developing a new instrument, named "opto-plasmonic tweezers," for optical manipulation of biological cells with fine orientation control and low optical-intensity requirement. Non-invasive manipulation of biological cells with light is an important tool for basic biological research. Opto-plasmonic tweezers use polarized light to excite localized surface-plasmon resonance, which consists of a collection of oscillating electrical dipoles, on a metal nanoparticle array. The orientation of these dipoles is parallel to the polarization direction of the light. They generate a patterned-radiation electric field that manipulates the cells through dielectrophoretic interactions, with orientation control dependent on the polarization of the light. Low optical intensity can be achieved due to the high gradient of the radiation field. A micromachined polarization controller will also be fabricated as the first step towards micro-instrumentation. The micro-polarization controller is expected to achieve sub-millisecond response time and therefore can achieve fast rotation control of the biological cells. This is a new instrument for manipulating single biological cells non-invasively using light. Such capability is important in biological research and applications. A chief virtue of the technology is its ability to rotate the cells with high resolution by changing the polarization direction of the light, which cannot be achieved by most of the optical manipulation approaches. Such capability opens the door to building structured biomaterials for potential applications in constructing biofilms and human tissue engineering. This instrument will also be miniaturized using micromachining technology so that it will have a small footprint and low cost. The success of this project will open up new directions for optical manipulations in biological research. This project will also give students valuable experience in doing interdisciplinary research.