Collaborative Research: Single walled nanotubes and Graphene based multiplexed sensors for hypergolic fuel detection

“该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。“项目目标：准确可靠地检测肼及其衍生物等自燃燃料在导弹防御局、航空、国土安全和化学工业中至关重要。更重要的是，这些传感器需要在低温下操作，尽管大多数广泛使用的化学传感器在中等高温下操作。已知单壁碳纳米管和单层石墨烯在室温下对局部化学环境的变化表现出极端的敏感性。该提案提出了一种制造传感器平台的方法，该传感器平台由碳纳米管和石墨烯阵列组成，具有系统性改性的表面特性。智力优点：所提出的新型传感器机制是基于碳纳米管和石墨烯的热电电压的转换。将纳米管和石墨烯串联集成可以弥补每种结构的局限性。与传统的电阻响应相比，热电功率被认为是更有信息性和更敏感的。公共加热器为所有传感器元件的热电电压转换提供必要的温度梯度，从而提供用于多路复用的简单手段。该提案的主旨是通过理解支撑选择性和传感特性的机制来改善基于碳纳米管和石墨烯的气体传感器的传感特性。热电电压测量将使得能够使用到标准电子器件的简单接口，而不需要通过每个传感器灯丝的激励电流。拟议的研究将导致制造上级气体/化学传感器的基础上（i）碳纳米管网络和石墨烯的多路复用的新平台（ii）基于热电电压的转换的传感技术。此外，拟议的研究在许多方面具有变革性，例如石墨烯纳米带的受控形成和通过简单的拾取和放置技术在测试平台上控制石墨烯的沉积。所提出的方法的关键组成部分包括静电工具的石墨烯的操作。从这项研究中获得的知识将有益于未来的纳米电子学和纳米科学超越这个项目。 更广泛的影响：拟议的项目将具有科学和教育影响。科学影响与进一步理解支撑制造技术的原理有关，这些原理包括高性能，气体和化学品在表面的相互作用，以及表面改性对碳纳米管和石墨烯敏感性的影响。结合路易斯维尔大学和托莱多大学的努力，将启动新的研究培训和推广活动教育计划。两名研究生将被赞助在两个研究实验室之间交流研究知识/设施。外展计划包括高中社区参与研究，研讨会和奖学金的准备。这些外联活动将为路易斯维尔/肯塔基州和托莱多/俄亥俄州代表性不足的女学生社区提供一切机会。研究人员计划开发一本教科书和一本流行的进步纳米科学书籍，这对后代来说是非常有益的资源。这些活动将提高公众对纳米技术和当前纳米材料技术的认识。研究成果将通过在这两个机构共享课程材料整合到本科和研究生课程中。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Project Objective: Accurate and reliable detection of hypergolic fuels such as hydrazine and its derivatives is vital in missile defense agency, aviation, homeland security, and chemical industry. More importantly these sensors need to be operated at low temperatures though most of the widely used chemical sensors operate at moderately high temperatures. Single walled carbon nanotubes and monolayer graphene are known to exhibit extreme sensitivity towards the changes in the local chemical environment at room temperatures. This proposal presents a methodology to fabricate a sensor platform consisting of arrays of carbon nanotubes and graphene with systematically modified surface properties. Intellectual Merit:The proposed novel sensor mechanism is based on the transduction of thermoelectric voltage of carbon nanotubes and graphene. Integration of nanotubes and graphene in tandem can complement for the limitations of each structure. Thermoelectric power is believed to be more informative and sensitive compared to conventional resistive response. A common heater provides the necessary temperature gradient for the transduction of thermoelectric voltage for all the sensor elements providing easy means for multiplexing. The main thrust of this proposal is to improve the sensing properties of carbon nanotube and graphene based gas sensors by understanding the mechanism underpinning the selectivity and sensing properties. Thermoelectric voltage measurement would enable the use of simple interface to standard electronics without need of an excitation current through each sensor filament. The proposed research will lead to fabrication of superior gas/chemical sensors based on (i) a novel platform of multiplexing of carbon nanotube networks and graphene (ii) a sensing technique based on the transduction of thermoelectric voltage. Also the proposed research is transformative in many ways such as controlled formation of Graphene Nano-ribbons and controlled depositions of graphene by a simple pick and place technique onto test platforms. The key component of the proposed method includes manipulation of graphene by electrostatic tools. The knowledge obtained from this research will be beneficial in future nanoelectronics and nanoscience beyond this project. Broader Impact:The proposed project will have both scientific and educational impact. The scientific impact is associated with the furthering of the fundamental understanding of principles underpinning the fabrication techniques towards high performance, interaction of gases and chemicals at surfaces, and surface modification effects on sensitivity of carbon nanotubes and graphene. Combining the efforts at The University of Louisville and The University of Toledo, new education programs for research training and outreach activities will be initiated. Two graduate students will be sponsored to exchange research knowledge/facilities between the two research laboratories. The outreach programs include involvement of high school communities in research, workshops, and preparation for scholarships. These outreach activities will provide every opportunity for underrepresented and female student communities in Louisville/Kentucky and Toledo/Ohio. The investigators plan to develop a text book and a popular book in progressive nanoscience that can be highly beneficial resources for future generation. These activities will enhance the public awareness about nanotechnology and current nanomaterials technology. The research outcomes will be integrated into the undergraduate and graduate curriculum by sharing the course materials at both institutions.