NIRT: Heterogeneous Integration of Nanowires for Chemical Sensor Arrays

智能优点：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，对环境、生物医学、过程控制和安全相关的应用非常重要。将化学传感器扩展到纳米尺度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应用提供前所未有的机会。为此，我们必须创建低成本、低功耗、大规模并行的化学传感器阵列，并将其与芯片上的数据处理相结合。该项目将汇集来自三个机构的跨学科团队来研究与这一目标相关的基本问题。该项目结合了化学家在纳米传感器合成、合成和芯片数据处理方面的专业知识材料和器件表征的物理学家，异质集成和测试电路设计的电气工程师，以及新型低功耗电路架构的设计、制造和测试的计算机科学家。虽然这个项目专门关注纳米传感器阵列，但它解决的问题是将许多不同类型的功能纳米级对象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基础上，为此，我们的团队带来了一些独特的新材料和技术。Mallouk和Semancik开发了一种将化学传感器条结合到模板生长的金属纳米线中的方法。这些纳米线将光刻长度尺度(微米纳米线长度)与纳米尺度(直径和条纹长度为30-300 nm)连接起来。合成技术允许传感材料的化学性质相当不同。我们将专注于三种不同的传感器平台--化学阻性金属氧化物、本征导电聚合物和导电聚合物复合材料--它们将在传感器阵列中提供良好的正交性。传感材料和纳米线的物理性质将使用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地耦合在一起，以便在分子水平上了解信号转导和标度效应，从而指导传感器的优化。Mayer和Eworth已经开发了一种用于在光刻定义的电路中放置纳米线的电流体对准技术。这将是将纳米传感器并行地异质集成到大阵列中的有力工具。成品率、器件密度和测试/逻辑电路集成将通过与Irwin和Narayan合作的模拟和实验相结合的方法来解决。最后，Irwin，Narayanan，Narayanan梅耶尔将设计和测试一种有效控制传感器操作的占空比并在本地处理阵列响应的CMOS传感器处理结构。器件/电路测试与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。广泛的影响：NIRT团队将在研究生、本科生、高中和K-8级别的教育和推广活动中应用其不同的科学背景。该研究计划有很强的指导女性、少数族裔、本科生和高中生的元素。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体验。在该计划的每个夏天，NIRT的教职员工和学生将与宾夕法尼亚州立大学行动潜力工作人员合作，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，它们将小学和中学教师与学生聚集在一起，以便教师可以在实际环境中使用新的课程材料。NSF资金将用于支持来自我们当地以外地区的教师的参与，以增加推广计划的地理和少数族裔影响。

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.