Investigation of Microsphere Convective Deposition for Photonic and Biological Applications

用于光子和生物应用的微球对流沉积研究

• 批准号: 0828426
• 负责人: James Gilchrist
• 金额: $ 30万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0828426&HistoricalAwards=false
• 关键词: Investigation; Microsphere; Convective; Deposition; Photonic

CBET-0828426GilchristThe proposed research will generate a fundamental description of the physics involved in the deposition of a monolayer of particles using convective self-assembly. Drawing an evaporating meniscus across a substrate, a process related to the "coffee ring effect" and the Langmuir-Blodgett technique, forms a structure of particles ranging from random and ordered sub-monolayer to well-ordered multilayers. Although many recently developed processes take advantage of this technique, primary questions remain regarding the fundamental physics involved with particle convection and self-assembly. In situ investigation of monolayer deposition will be performed using high speed confocal laser scanning microscopy. Preliminary results suggest many parameters not previously considered affect deposition and various mechanisms generate microsphere pre-alignment in the thin film prior to deposition. Experiments that incorporate processing, suspension, and substrate conditions not previously explored will be used to develop a model to shed light onto the mechanisms that link the controllable macroscopic properties to the microstructure. Fabrication of colloidal monolayers will be used directly in two specific applications. Performance of InGaN light emitting diodes (LEDs) is inhibited by the index mismatch of the GaN/air interface. The proposed process will be used to fabricate microlens arrays where the microstructure determines the light extraction efficiency. Preliminary results demonstrate increased light output power by 219%. In a parallel effort, design of monolayer arrays labeled with antibodies for whole blood detection of CD4+ lymphocytes will enable enhanced screening for HIV/AIDS. The microstructure of these deposited monolayers will dictate the capture efficiency and proliferation of target cells and enable release of these cells for analysis. Broader Impacts: Although colloidal convective deposition is used in many technologies, the fundamental physics is poorly understood. This research will develop a predictive model based on observations obtained from direct 3D particle tracking during deposition for various surface and suspension properties. Through this research, the importance of controlling this microstructure will be demonstrated in two applications that have significant potential impact on their respective industries. First, the microlens arrays fabricated using this technique have the potential to surmount the current state-of-the-art LED photon extraction, allows scale-up for industrial applications, and is low-cost as compared to current techniques of surface patterning via electron beam lithography. In whole blood analysis, this technique can be generalized for a variety detection schemes and will aid development of a process that aims to bring low cost detection to regions lacking proper medical resources. This work will directly provide both graduate and undergraduate educational opportunities in an area at the convergence of several technologically-critical research areas including microfluidics, suspension transport, photonics, and bioengineering.

CBET-0828426Gilchrist拟议的研究将对使用对流自组装的粒子单层涉及的物理学产生一个基本描述。在底物上绘制蒸发的半月板，这是与“咖啡环效应”和Langmuir-Blodgett技术相关的过程，形成了从随机和有序的子单层到有序的多层的颗粒结构。尽管许多最近开发的过程利用了这项技术，但关于粒子对流和自组装涉及的基本物理学的主要问题仍然存在。原位研究单层沉积将使用高速共聚焦激光扫描显微镜进行。初步结果表明，许多参数以前未考虑影响沉积，各种机制在沉积之前会在薄膜中产生微球前对齐。包括以前未探索的处理，悬架和底物条件的实验将用于开发模型，以将可控宏观特性与微结构联系起来的机制。胶体单层的制造将直接用于两个特定的应用中。 GAN/空气界面的索引不匹配抑制了Ingan Light发射二极管（LED）的性能。所提出的过程将用于制造微芯阵列，其中微结构决定了光提取效率。初步结果表明，发光功率增加了219％。在平行的努力中，用抗体标记的单层阵列设计用于CD4+淋巴细胞的全血的抗体将有助于增强HIV/AIDS的筛查。这些沉积单层的微观结构将决定靶细胞的捕获效率和增殖，并使这些细胞释放进行分析。更广泛的影响：尽管在许多技术中都使用了胶体对流沉积，但基本物理学的理解很少。这项研究将根据从直接的3D粒子跟踪在沉积过程中的观察结果中开发出一个预测模型，以供各种表面和悬浮性能。通过这项研究，将在两个对各自行业产生重大影响的应用中证明控制这一微观结构的重要性。首先，使用该技术制造的微芯阵列有可能刺激当前最新的LED光子提取，允许对工业应用进行扩展，并且与通过电子束光刻的表面图案技术相比，相比之下。在全血分析中，可以将此技术推广到多样性检测方案，并将有助于开发一个旨在将低成本检测带给缺乏适当医疗资源的地区。这项工作将直接在几个技术关键的研究领域的融合区域中直接提供研究生和本科教育机会，包括微流体，悬架运输，光子学和生物工程。