Acquisition of Nanomechanical Instrumentation

该补助金用于购买纳米压痕系统，包括纳米硬度测试仪（NHT）和原子力显微镜。许多涉及材料表征和纳米力学应力分析的不同研究小组将从NHT的收购中受益。纳米压痕系统将致力于MEMS材料在微米和纳米尺度上的微观力学行为的研究。它允许各种各样的测试，包括亚微米尺寸的硬度测试，微划痕测试，循环压痕过程中的接触疲劳，以及恒定载荷蠕变测试。该仪器将用于几个研究项目：（1）作为微制造工艺和温度的函数的MEMS材料的微机械性能的测量，以提供用于建模的微机械性能和MEMS微部件的工艺-性能关系的理解，（二）硅晶片的接触疲劳和与两个硅表面之间的循环接触或累积损伤相关的表面裂纹萌生的研究，识别MEMS器件中接触损伤和失效的关键变量，以及（3）研究MEMS微元件两个表面之间由于界面力（如毛细管力、货车范德华力和静电力）引起的粘附现象，以了解控制微尺度上固体接触表面之间键合的主要机制。这是肯塔基州大学的第一台纳米硬度计。这将对MEMS结构的微观力学研究以及MEMS材料和纳米材料的表征产生重大影响。例如，很明显，表面和界面应力在确定MEMS微部件的变形特性中起重要作用，这是由于高的表面积与体积比。通过纳米压痕测试确定的微机械性能将允许考虑表面效应，如表面应力。长期的研究目标是发展相关的微机电系统的先进材料的材料特性（包括弹性，塑性，粘附和断裂）的理解。

The grant provides support for the acquisition of a nano-indentation system, consisting of a nano-hardness tester (NHT) and an atomic force microscope. Many diverse research groups that are involved in the characterization of materials and in nanomechanical stress analysis will benefit from the acquisition of the NHT. The nano-indentation system will be devoted to the study of micromechanical behavior of MEMS materials on both the micrometer and the nanometer scale. It allows a wide variety of tests, including submicron-sized hardness tests, micro-scratch tests, contact fatigue during cyclic indentation, and constant load creep tests. The instrument will be used in several research projects: (1) the measurement of micromechanical properties of MEMS materials as a function of microfabrication processes and temperature to provide both the micromechanical properties for modeling and the understanding of processing-properties relationships of MEMS microcomponents, (2) the investigation of the contact fatigue of silicon wafers and surface crack initiation associated with cyclic contact between two silicon surfaces or accumulated damage to identify the key variables responsible for contact damage and failure in MEMS devices, and (3) the study of adhesion phenomena between two surfaces of MEMS microcomponents due to interfacial forces, such as capillary, van der Waals, and electrostatic forces to understand the dominant mechanisms controlling the bonding between solid contact surfaces on the microscale. %%%This nano-hardness tester is the first of its kind at the University of Kentucky. It will have a large impact on research dealing with micromechanics of MEMS structure and characterization of MEMS materials and nanomaterials. For example, it is clear that surface and interface stresses play an important role in determining the deformation characteristics of MEMS microcomponents due to the high surface area to volume ratio. The micromechanical properties determined via nanoindentation tests will allow for consideration of surface effects, such as surface stresses. The long-term research goal is to develop an understanding of the material properties (including elasticity, plasticity, adhesion, and fracture) of advanced materials relevant to micro-electromechanical systems.