NIRT: Heterogeneous Integration of Nanowires for Chemical Sensor Arrays

知识优势：“电子鼻”化学传感器阵列用于检测复杂混合物中的痕量分析，对于环境，生物医学，过程控制和安全相关应用非常重要。将化学传感器缩放到纳米尺寸将为电子鼻阵列在手持设备、远程监控、机器人、医疗诊断、传感器粉尘和其他新应用中的实现带来前所未有的机会。要做到这一点，我们必须创造低成本、低功耗、化学多样性传感器的大规模并行阵列，并将它们与芯片上的数据处理集成在一起。拟议的项目将汇集来自三个机构的跨学科团队，共同研究与这一目标相关的基本问题。该项目结合了纳米传感器合成方面的化学家、材料和器件表征方面的物理学家、异构集成和测试电路设计方面的电气工程师以及设计、制造和测试新型低功耗电路架构的计算机科学家的专业知识。虽然这个项目特别关注纳米传感器阵列，但它所解决的问题是将许多不同种类的功能纳米级物体集成到硅基电路中的通用问题。我们的方法建立在现有的化学传感器阵列平台和数据分析方法的知识库上，我们的团队带来了一些独特的新材料和技术。Mallouk和Semancik开发了一种方法，将化学传感器“条纹”整合到模板生长的金属纳米线中。这些纳米线将光刻长度尺度（微纳米线长度）与纳米尺度（30-300纳米直径和条纹长度）连接起来。合成技术允许感觉材料的化学性质相当多样化。我们将重点介绍三种不同的传感器平台-化学电阻金属氧化物，本质导电聚合物和导电聚合物复合材料-它们应该在传感器阵列中提供出色的正交性。感官材料和纳米线的物理特性将使用Evoy和Semancik设计的测试结构进行研究，特别关注纳米传感器响应的热和时间特征。纳米传感器的合成和物理表征将紧密耦合，以便对信号转导和缩放效应的分子水平理解可以指导传感器的优化。Mayer和Evoy开发了一种电流体对准技术，用于将纳米线放置在光刻定义的电路中。这将是将奈米感测器平行异质整合成大型阵列的有力工具。在Irwin和Narayanan的合作下，产量、器件密度和测试/逻辑电路集成等问题将通过模拟和实验相结合的方法来解决。最后，Irwin，Narayanan和Mayer将设计并测试一种CMOS传感器处理结构，该结构可以有效地控制传感器操作的占空比，并在本地处理阵列响应。器件/电路测试和纳米传感器合成和表征之间的反馈将把整个项目联系在一起。更广泛的影响：NIRT团队将在研究生、本科生、高中和K-8年级的教育和推广活动中应用其多样化的科学背景。该研究项目对女性、少数民族、本科生和高中生有很强的指导作用。它还将通过与合作伙伴实验室的交流，为研究生提供跨学科的经验。在项目的每个夏天，NIRT的教师和学生将与宾夕法尼亚州立大学行动潜力的工作人员合作，针对不同的当前主题开发一系列5 -8年级的科学夏令营。这些夏令营的独特之处在于，他们将中小学教师与学生聚集在一起，让教师在实际环境中使用新的课程材料。国家科学基金会的资金将用于支持本地以外地区的教师参与，以增加外联计划的地理和少数民族的影响。

Intellectual merit:"Electronic nose"chemical sensor arrays are used to detect trace analytesin complex mixtures,and are important for environmental,biomedical,process control,andsecurity-related applications.Scaling chemical sensors to nanometer dimensions will openunprecedented opportunities for implementation of electronic nose arrays in and-held devices,remote monitoring,robotics,medical diagnostics,sensor dust,and other novel applications.To do this,we must create low cost,low power,massively parallel arrays of chemically diversenanosensors and integrate them with on-chip data processing.The proposed project will bringtogether an interdisciplinary team from three institutions to work on the fundamental problemsconnected with this goal.The project combines the expertise of chemists in nanosensorsynthesis,physicists in materials and device characterization,electrical engineers inheterogeneous integration and test circuit design,and computer scientists in the design,fabrication,and testing of novel low-power circuit architectures.While this project focusesspecifically on nanosensor arrays,the problems it addresses are generic to the integration ofmany different kinds of functional nanoscale objects into silicon-based circuits.Our approach builds on an existing knowledge base of chemical sensor array platforms anddata analysis methods,to which our team brings some unique new materials and techniques.Mallouk and Semancik have developed a method for incorporating chemical sensor "stripes"intotemplate-grown metal nanowires.These nanowires connect the lithographic length scale (micronnanowire length)with the nanoscale (30-300 nm diameter and stripe length).The synthetictechnique allows the chemical nature of the sensory material to be quite diverse.We will focuson three different sensor platforms -chemoresistive metal oxides,intrinsically conductingpolymers,and conductive polymer composites -which should provide excellent orthogonality insensor arrays.The physical properties of the sensory materials and of the nanowires will bestudied using test structures devised by Evoy and Semancik,focusing in particular on the thermaland temporal signatures of the nanosensor response.The synthesis and physicalcharacterization of the nanosensors will be tightly coupled so that a molecular-levelunderstanding of signal transduction and scaling effects can guide the optimization of the sensors.Mayer and Evoy have developed an electrofluidic alignment technique for placing nanowires inlithographically defined circuits.This will be a powerful tool for parallel heterogeneousintegration of the nanosensors into large arrays.Issues of yield,device density,and testing/logiccircuit integration will be addressed through a combined approach of simulation and experiment,in collaboration with Irwin and Narayanan.Finally,Irwin,Narayanan,and Mayer will designand test a CMOS sensor processing fabric that efficiently controls the duty cycle of sensoroperation and processes the array response locally.Feedback between device/circuit testing andnanosensor synthesis and characterization will tie the whole project together.Broader impact:The NIRT team will apply its diverse scientific background in educationand outreach activities at the graduate,undergraduate,high school,and K-8 levels.The researchprogram has a strong element of mentoring of women,minorities,undergraduates,and high schoolstudents.It will also provide a cross-disciplinary experience for graduate students throughexchange with partner laboratories.In each summer of the program,NIRT faculty and studentswill team with Penn State Action Potential staff to develop a series of 5 th -8 th grade science campson different current topics.The unique aspect of these camps is that they bring elementary andmiddle school teachers together with students,so that teachers can use new curricular material ina practical environment.NSF funds will be used to support the participation of teachers frombeyond our local area,to increase the geographic and minority impact of the outreach program.