SGER: A Novel Gas Sensing Platform with Tin Oxide Nanocrystals Supported on a Carbon Nanotube

小型化气体传感器可以快速准确地检测和区分微量气体/蒸气及其混合物，在许多应用中非常有吸引力，例如环境监测、医疗诊断、食品加工、芯片实验室分析设备和其他工业过程的控制。本课题的研究目的是探索一种用于小型化气体传感器的碳纳米管（CNT）涂覆SnO2纳米晶体的新型传感平台。传感平台是基于我们最近在纳米颗粒组装方面的发明，并承诺使小型化的气体传感器具有卓越的灵敏度和灵活性，以实现多传感功能的选择性。基于多壁碳纳米管的新型传感平台已被证明可以在室温下检测低浓度气体，克服了SnO2传感器众所周知的缺点（高温操作）。然而，由于半导体单壁碳纳米管（SWCNTs）的载流子密度相对较低，因此传感性能可以显著增强。该项目的具体目标是制造具有SnO2纳米晶体- swcnt结构的气体传感器，并表征新型传感器的传感性能。研究了纳米晶体尺寸和面密度对杂化纳米结构性能和传感器性能的影响。本项目的主要创新点是新型的室温气体传感平台。混合纳米晶体-碳纳米管系统作为传感元件优于任何一种组成元件。由于纳米晶体和碳纳米管之间的电子耦合，该平台为设计具有量子力学传感属性的气体传感器提供了一个全新的机会。所提出的方法可以实现高效的单纳米颗粒传感器的工程设计，该传感器具有单分子的最终灵敏度，并且只需通过掺入不同类型的纳米晶体（例如通过掺杂）即可并行检测大量分析物分子的优势。该项目的广泛影响是多方面和深远的。具有优异性能和低功耗的小型化传感器将通过实现安全和健康的生活环境直接造福社会。新型混合纳米结构传感器的传感机理将为传感器性能的提高开辟新的方向。该项目的成果将使混合纳米晶体-碳纳米管结构的广泛创新应用成为可能。通过参与尖端的探索性研究，以及将小型纳米技术项目整合到现有的核心机械工程高级实验课程和新开发的纳米制造研究生课程中，该项目将有助于培养研究生和本科生在纳米技术和气体传感方面的能力。它还将通过与威斯康星职业学院合作的“科学星期六”，为教育K-12学生、教师和纳米技术领域的公众做出贡献。将鼓励妇女和少数民族的参与。

CBET-0803142ChengMiniaturized gas sensors that rapidly and accurately detect and differentiate trace amount of gases/vapors and their mixtures are extremely attractive for many applications, such as environmental monitoring, medical diagnosis, food processing, lab-on-a-chip analytical devices, and control of other industrial processes. The research objective of this proposal is to explore a novel sensing platform of a carbon nanotube (CNT) coated with SnO2 nanocrystals for miniaturized gas sensors. The sensing platform is based on our recent invention in nanoparticle assembly and promises to enable miniaturized gas sensors with superior sensitivity and flexibility to realize selectivity for multisensing capabilities. The new sensing platform based on multiwalled CNTs has been shown to sense low-concentration gases at room temperature, overcoming the well-known disadvantage of SnO2 sensors (high-temperature operation). However, the sensing performance can be significantly enhanced with semiconductor single-walled CNTs (SWCNTs) due to the relatively lower charge carrier density in these tubes. The specific goals of the project are to fabricate gas sensors with SnO2 nanocrystals-SWCNT structures and to characterize the sensing performance of the novel sensors. Effects of nanocrystal size and areal density on hybrid nanostructure properties and the sensor performance will be investigated. Major innovation of the project is the novel gas sensing platform for room-temperature sensing. The hybrid nanocrystal-CNT system as a sensing element is superior to either of the constituent components. The platform provides a radically new opportunity to engineer gas sensors with quantum-mechanical sensing attributes due to electronic coupling between the nanocrystal and the CNT. The proposed approach may enable engineering of a highly efficient single nanoparticle sensor with an ultimate sensitivity of a single molecule and with the advantage of parallel detection of a large array of analyte molecules simply by incorporating different types of nanocrystals, e.g., through doping. Broader impacts of this project are multi-faceted and far-reaching. Miniaturized sensors with superior performance and low power consumption will directly benefit society by enabling a secure and healthy living environment. The new sensing mechanism for the hybrid nanostructure sensor will lead to a new direction for improving sensor performance. The project results will enable a wide range of innovative applications of hybrid nanocrystal-CNT structures. The project will contribute to the training of graduate and undergraduate students in nanotechnology and gas sensing through their participation in the cutting-edge exploratory research and the integration of small nanotechnology projects into an existing core Mechanical Engineering senior experimentation course and a newly developed graduate-level course on nanomanufacturing. It will also contribute to educating K-12 students, teachers, and the general public in the area of nanotechnology through "Science Saturdays" in collaboration with Wisconsin Career Academy. Participation of women and minorities will be encouraged.