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

通过在微米和纳米尺度上操纵流体，可以精确地观察和设计一些未知的物理和化学现象。S长期的研究议程在于开发集成微系统，通过利用流体运动的精密机电转换，实现对非电环境现象的这种接口和反向工程。这份为期5年的职业建议书专注于开发一款可穿戴的？微气相色谱(？GC)系统能够对一类不同的空气污染物(挥发性有机化合物：VOCs)进行实时、现场和个人监测，以便为个人提供早期预警。具体地说，PI建议研究一种全新的气相色谱配置的基础科学，这种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的小型化障碍，必须解决在尺寸限制下的色谱分离能力和射流泵浦能力之间的根本科学冲突。气相色谱系统通过沿着柱子赛跑目标来识别目标，从而实现空间分离。理想情况下，较长的柱在更多目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，这需要超大尺寸的泵，从而阻碍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的便携性，应该在小型化的尺寸中获得足够的柱长度和射流头部压力。目前还没有可行的选择来实现这两个目标。该项目建议通过以下方式解决这些障碍：(1)研究基础科学并建立所建议的新型气相色谱结构的预测模型，(2)检查并最大化规模化条件下的性能容量和限制，以及(3)实验演示利用用于环境监测的新结构的功能GC操作：检测挥发性有机化合物(VOCs)。智能优点：尽管最近的微型气体传感器作为一种使能工具前景看好，但除非整个集成系统真正便携，否则仍然需要笨重的泵送系统。该项目通过在基于气相色谱的传感器中提供一种新的范式转换概念来避免这种困境。这一拟议概念的科学确立有望在所有规模的通用化学和生物检测技术和仪器方面带来革命性的进步。此外，实验演示将为具有新配置的多组分气相色谱系统提供新的设计指南。更广泛的影响：最近的文献和政府政策越来越多地报告了实时了解工作场所、公共和家庭环境状况的日益增长的需求。预计拟议的项目将把微系统技术、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影响。具体地说，该项目的教育目标是提高代表不足的高中生和K-12学生对环境监测的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，并通过与当地一家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。这个项目是高度跨学科的工程和科学，也将使学生接触到重要的社会问题，以实现均衡的教育。

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.