SGER: MEMS-Based Preconcentrators with Nano-Structured Adsorbents for Micro Gas Chromatography

SGER：用于微型气相色谱的基于 MEMS 的具有纳米结构吸附剂的预浓缩器

• 批准号: 0610213
• 负责人: Masoud Agah
• 金额: $ 5万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0610213&HistoricalAwards=false
• 关键词: SGER; MEMS; Based; Preconcentrators; Nano

Abstract Proposal Title: SGER MEMS-Based Preconcentrators with Nano-Structured Adsorbents for Micro Gas Chromatography. Proposal Number: CTS-0610213 Principal Investigator: Masoud Agah, Institution: Virginia Polytechnic Institute and State UniversitySince the 1950s, gas chromatography (GC) has been a common approach for analysis of volatile mixtures in which the components are differentiated in space and time. Conventional GCs tend to be large, fragile, and relatively expensive table-top instruments with high power consumption, but they are known to deliver accurate and selective analysis. The use of MEMS technology for GC development is a promising approach to micro-instruments having lower cost, smaller size, lower power consumption, faster analysis, and greatly increased portability for in-field use. Such systems will make gas chromatography a pervasive method for gas analysis, with applications in homeland security, monitoring food freshness, industrial process control, biomedical diagnostics, and improving environment quality. In GCs, due to low concentration of volatile and semivolatile organic compounds in the environment, a preconcentrator prior to real-time chemical sensor measurement is needed to automatically sample the ambient gas and improve the measurement sensitivity by 10-1000 folds. Miniaturization of preconcentrators using silicon micromachining techniques can overcome the limitations of conventional methods (using a narrow bore metal tubing) by reducing the device size, power consumption, dead volume, and thermal mass. Although achieving promising results, microfabricated preconcentrators still face difficult challenges in achieving a preconcentrator with high adsorbent capacity (1000), low power consumption (1W peak-power), and narrow injection plug width (0.2s). Herein, we will address these challenges by combining and bridging the gap between top-down miniaturized processing and bottom-up self-assembly approaches for the first time to develop miniaturized preconcentrators. The objective of this work is to employ MEMS technology to fabricate preconcentrators having on-chip thermal desorption capability and to utilize nanotechnology to coat the preconcentrator interior surfaces with nano- structured materials such as ionically self-assembled films. Three specific aims are proposed: 1) Fabrication of lowmass (low-power) preconcentrators having integrated heaters and temperature sensors for thermal desportion using high-aspect-ratio silicon etching techniques and a silicon-on-glass process, 2) Deposition of ionic self-assembled multilayers (ISAM) on the preconcentrator walls as adsorbents only a few tens of nanometers thick, and 3) Evaluation of the preconcentrator performance in terms of breakthrough time and volume, concentration factor, and temperature requirements. We envision that the use of nanostructured adsorbents (such as nanoparicles) with high surface to volume ratio ensures that the preconcentrator has sufficient surface area for trapping the sample stream. This reduces the preconcentrator volume and hence decreases the overall mass of the structure. The low-mass preconcentrator allows rapid thermal desorption to generate narrow bands for injection into the GC column.The broader impacts of this exploratory project will set an outstanding example of how MEMS and Nanotechnology can become highly complementary methodologies to develop low-cost, low power, high-performance devices that impact industries across the globe considering that the worldwide market for GC instruments is estimated to be around $1 billion annually. This research will also advance discovery while promoting teaching and learning at undergraduate and graduate levels. This includes recruiting of graduate students from under-represented groups into a highly interdisciplinary research program, and incorporation of the project results in the courses taught by the PIs in three different departments, namely MEMS: from fabrication to application,Nanotechnology, and Advanced Analytical Chemistry-Separation Science. Additionally, the outcome of this research will be widely disseminated to the engineering and scientific communities in journals and in presentation at multidisciplinary conferences.

摘要提案标题：SGER基于MEMS的微气相色谱纳米结构吸附剂预浓缩器。提案编号：CTS-0610213首席研究员：Masoud Agah，机构：弗吉尼亚理工学院和州立大学自20世纪50年代以来，气相色谱法（GC）一直是分析挥发性混合物的常用方法，其中组分在空间和时间上是不同的。传统的GC往往是大型、脆弱且相对昂贵的台式仪器，具有高功耗，但已知它们可以提供准确和选择性的分析。使用MEMS技术进行GC开发是一种有前途的方法，使微型仪器具有更低的成本、更小的尺寸、更低的功耗、更快的分析速度和大大增加的现场使用的便携性。这些系统将使气相色谱法成为一种普遍的气体分析方法，应用于国土安全，监测食品新鲜度，工业过程控制，生物医学诊断和改善环境质量。在气相色谱中，由于环境中挥发性和半挥发性有机化合物的浓度低，需要在实时化学传感器测量之前的预浓缩器来自动采样环境气体，并将测量灵敏度提高10-1000倍。使用硅微机械加工技术的预浓缩器的小型化可以通过减小设备尺寸、功耗、死体积和热质量来克服传统方法（使用窄孔金属管）的局限性。尽管取得了有希望的结果，但微制造预浓缩器在实现具有高吸附剂容量（1000）、低功耗（1 W峰值功率）和窄注入塞宽度（0.2s）的预浓缩器方面仍然面临困难的挑战。在这里，我们将解决这些挑战，结合和弥合自上而下的小型化处理和自下而上的自组装方法之间的差距差距，首次开发小型预浓缩器。这项工作的目的是采用MEMS技术来制造具有片上热解吸能力的预浓缩器，并利用纳米技术来涂覆预浓缩器的内表面与纳米结构的材料，如离子自组装膜。提出了三个具体目标：1）低质量的制造具有集成加热器和温度传感器的（低功率）预浓缩器，用于使用高纵横比硅蚀刻技术和玻璃上硅工艺进行热分解，2）在预浓缩器壁上沉积离子自组装多层（ISAM）作为仅几十纳米厚的吸附剂，和3）根据穿透时间和体积、浓缩因子和温度要求评价预浓缩器的性能。我们设想使用具有高表面积与体积比的纳米结构吸附剂（例如纳米颗粒）确保预浓缩器具有足够的表面积用于捕获样品流。这减小了预浓缩器的体积，因此减小了结构的总质量。低质量预浓缩器允许快速热解吸以产生用于注入GC柱的窄带。该探索性项目的更广泛影响将为MEMS和纳米技术如何成为开发低成本，低功耗，考虑到GC仪器的全球市场估计约为$，影响地球仪行业的高性能设备每年10亿。这项研究也将推进发现，同时促进本科和研究生水平的教学和学习。这包括从代表性不足的群体招募研究生进入一个高度跨学科的研究计划，并将项目结果纳入三个不同部门的PI教授的课程，即MEMS：从制造到应用，纳米技术和高级分析化学分离科学。此外，这项研究的成果将在期刊和多学科会议上广泛传播给工程和科学界。