CAREER: Next-Generation Micro Gas Chromatography System Toward Ultra-High Capacity,Selectivity, and Portability For Distributed Environmental Awareness

通过对流体进行微纳尺度的操控，可以对一些未知的物理和化学现象进行精确的观测和设计。派？的长期研究议程在于集成微系统的发展，使这种接口和逆向工程的非电环境现象，利用精密机电转换通过流体运动。这5年的职业生涯建议的重点是发展一个？可穿的？微型气相色谱（CGC）系统，能够对一类各种空气污染物（挥发性有机化合物：VOC）进行实时、现场和个人监测，以便对个人进行早期预警。具体而言，PI建议研究一种全新的气相色谱配置的基础科学，该配置有望克服小型化的主要障碍，并实现超越当前最先进技术的超高容量，选择性和便携性。 为了克服小型化气相色谱装置中的小型化障碍，必须解决色谱分离能力和尺寸限制下的流体泵送能力之间的基本科学冲突。气相色谱系统通过使目标物沿着色谱柱运动而导致空间分离来识别目标物。理想地，较长的柱在更多的靶标之间提供更远的隔离，从而提供更高的检测能力。然而，它施加了快速增加的流体阻力，这需要过大的泵，从而阻止了整个系统的真正便携性。因此，为了在GC中实现高容量和可穿戴便携性，应在小型化尺寸中获得足够的柱长度和流体压头压力。目前没有可行的办法来实现这两个目标。该项目提出通过以下方式解决这些障碍：（1）调查基础科学并建立所提出的新型气相色谱配置的预测模型，（2）检查并最大化缩放下的性能容量和限制，以及（3）实验性地展示利用新配置进行环境监测的功能GC操作：检测挥发性有机化合物（VOC）。智力优势：尽管作为一种使能工具有很大的希望，但最近的微尺度气体传感器仍然需要庞大的泵送系统，这阻碍了整个集成系统的真正便携性。该项目通过在基于气相色谱的传感器中提供新的范式转换概念来避免这种困境。拟议概念的科学确定预计将导致所有规模的通用化学和生物检测技术和仪器的革命性进步。此外，实验演示将提供一个新的多组分气相色谱系统的设计与新的配置指南。 更广泛的影响：最近的文献和政府政策越来越多地报道了在工作场所，公共场所和家庭实时了解环境条件的新兴需求。拟议的项目预计将把微系统技术，分析化学和环境教育结合在一起，在提高学术界和公众的环境意识方面产生协同效应。具体而言，该项目的教育目标是提高代表性不足的高中和K-12学生对环境监测重要性和科学技术作用的认识。该项目将教育下一代学生在这样的背景下微/纳米传感器技术的影响。该项目将通过新课程和实践模块培训多名研究生和本科生，并通过与当地科学博物馆的持续合作培训许多K-12学生了解基本的传感器概念。该项目是工程和科学之间的高度跨学科，也将使学生接触到重要的社会问题，以实现均衡教育。

Some unknown physical and chemical phenomena can be precisely observed and engineered by manipulating fluids in micro and nano scales. PI?s long-term research agenda lies in the development of Integrated Microsystems to enable such interface and reverse-engineering on non-electric ambient phenomena by utilizing precision electro-mechanical transduction via fluidic movement. This 5-year CAREER proposal focuses on developing a ?wearable? micro gas chromatography (ìGC) system to enable real-time, on-spot, and personal monitoring of a class of various airborne pollutants (Volatile Organic Compounds: VOCs) for early warning for individuals. Specifically, PI proposes to investigate fundamental sciences of an entirely novel gas chromatography configuration that is expected to overcome the major barrier in miniaturization and enable the ultra-high capacity, selectivity, and portability beyond the current state-of-the-art technology. To overcome the miniaturization barrier in scaled-down gas chromatography devices, the fundamental scientific conflict has to be resolved between the capacities of chromatographic separation and fluidic pumping under size restriction. Gas chromatography systems identify targets by racing them along a column resulting in spatial separation. Ideally a longer column provides farther isolation among more targets and thus higher detection capacity. However, it imposes rapidly-increasing fluidic resistance that requires over-sized pumps preventing true portability of the whole system. Therefore, in order to enable both high-capacity and wearable-portability in GCs, both the sufficient column length and fluidic head pressure should be attained in a miniaturized size. Currently there are no viable options to achieve both. This project proposes to address such barriers by: (1) investigating fundamental sciences and establishing a prediction model of the proposed novel gas chromatography configuration, (2) examining and maximizing performance capacity and limitation under scaling, and (3) experimentally demonstrating functioning GC operation utilizing the novel configuration for environmental monitoring: detection of volatile organic compounds (VOCs). Intellectual Merit: Although holding great promises as an enabling tool, recent micro-scale gas sensors still require bulky pumping systems barring true portability of the whole integrated system. This project obviates such dilemma by providing a novel paradigm-shifting concept in gas-chromatography-based sensors. Scientific establishment of the proposed concept is expected to lead to a revolutionary advancement in generic chemical and biological detection technology and instrumentation in all scales. Additionally, the experimental demonstration will provide a new design guideline for the multiple-component gas chromatography system with the new configurations. Broader Impact: Recent literature and government policy have increasingly reported the emerging demands of knowing environmental conditions in real-time at workplace, public, and home. The proposed project is expected to bring MicroSystems technology, analytical chemistry, and environmental education together creating synergetic impacts in increasing the environmental awareness in both academia and public. Specifically, the education objective of this project is to enhance the awareness of under-represented highschool and K-12 students of the importance in environmental monitoring and the roles of science and technology. This project will educate the next-generation students with the impacts of the micro/nano sensor technology in such a context. This project will train multiple graduate and undergraduate students through a new course and hands-on modules, and many K-12 students to the basic sensor concepts through on-going collaboration with a local science museum. This project is highly inter-disciplinary among engineering and science, and will also expose students to important social issues for balanced education.