A Micromachined Device for Mechanical Testing of Nano-scale Materials and Structures

我们提出了一种用于独立纳米薄膜拉伸测试的微机械结构。该设计将结合目前存在于不同机械测试设备中的元素，并将提供一些新功能。该设备的优点包括使用压阻式力传感器进行集成负载测量，在高应变率下进行非常敏感的应力测量，桌面测试兼容性，原位电子显微镜测试兼容性，固有试样对准以及在处理过程中保护试样。结合的能力将允许探索时间和温度依赖于各种薄膜材料的性能。设备制造的工艺流程将与各种各样的测试材料兼容，并适用于实验室之间的交换。完成的装置将通过研究20-100纳米尺寸的铝和铝合金薄膜的应变率效应来演示。在铝膜上进行的疲劳断裂研究也将展示测试设备的独特功能。该计划将为依赖于纳米级结构组件的设备的可靠设计提供必要的关键信息。虽然研究生将完成大部分工作，但每年将有几名本科生参与动手研究，使他们接触新兴纳米材料领域的概念和技术。正如以前的项目所显示的那样，大量的妇女代表将是这一努力的一部分。此外，新生将受益于基于先进材料的实践项目，这是一门面向所有理哈伊大学工程专业学生的新课程。利哈伊大学纳米和微机械行为实验室和电子显微镜设施的基础设施增强将推动纳米尺度材料和结构的机械行为的未来合作

We propose to fabricate a micromachined structure for tensile testing of freestanding nano-scale thin films. The design will combine elements that currently exist in different mechanical testing devices and will offer several new features as well. The benefits of the proposed device include integrated load measurement with a piezoresistive force sensor, very sensitive stress measurement at high strain rates, table-top testing compatibility, in-situ electron microscope testing compatibility, intrinsic specimen alignment, and protection of the specimen during handling. The combined capabilities will allow exploration of time and temperature dependent performance of various thin film materials. The process flow for device fabrication will be compatible with a wide variety of test materials and will be suitable for exchange between laboratories. The finished device will be demonstrated through a study of strain rate effects in aluminum and aluminum alloy films of 20-100 nm dimensions. A fatigue fracture study performed on aluminum films will also showcase the unique capabilities of the test device. The proposed program will provide critical information necessary for reliable design of devices that depend on nano-scale structural components. Although graduate students will be performing the majority of the work, several undergraduate students will be engaged each year in hands-on research, exposing them to concepts and techniques being developed for the emerging field of nanomaterials. Significant representation of women will be a part of this effort, as has been demonstrated in prior projects. Furthermore, freshmen will benefit from hands-on projects based on advanced materials through a new course in development intended for all Lehigh engineering students. Infrastructure enhancements to the Lehigh University Nano- and Micro-Mechanical Behavior Laboratory and the Electron Microscopy Facility will fuel future collaborations in mechanical behavior of nano-scale materials and structures