Micromaterials and microstructures - non contact characterisation using optical techniques

微材料和微结构 - 使用光学技术进行非接触式表征

• 批准号: EP/E053319/1
• 负责人: Brian Culshaw
• 金额: $ 86.05万
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE053319%2F1
• 关键词: Micromaterials; microstructures; non; contact; characterisation

Microscale Structures are becoming increasingly important in applications ranging from biological implants to display technologies. An essential characteristic of microstructures is their mechanical properties. Performing repeatable and accurate measurements of these properties on operational structures has to date proved to be extremely difficult. Such monitoring would enable the effects of fabrication steps during manufacture on mechanical properties to be reliably characterised. Additionally it would enable ready assessment of the impact of packaging, environmental conditions and continuous usage on mechanical integrity. This project focuses upon monitoring these mechanical properties (density, stiffness etc.) using a non contact optical technique. This approach uses an optical signal to produce an ultrasonic response in the material and this response is monitored optically. The complexity of this response enables the determination of mechanical material properties through curve fitting involving carefully structured numerical mathematical inversion techniques. For simple structures the response can be modelled analytically and this analytical model inverted numerically. For more complex structures reliable computer modelling is essential for both forward and inverse analysis. The project therefore has parallel strands examining both simple and more complex microstructures and making extensive use of finite element modelling techniques where appropriate to augment the experimental techniques. Additionally for very simple structures the measurement method will be referenced against contact based systems developed through our partners at the National Physical Laboratory. We have demonstrated the basic principle on larger scale geometrically simple structures and are confident that repeatability in the order of 1% is achievable. Extending the technique to microstructures does however present significant research challenges in realising gigahertz bandwidth ultrasonic excitation (where the wavelength is comparable to structural dimension) and detection and in accommodating more complex structural artefacts, in addition to producing microscale detection and excitation optics.

微尺度结构在从生物植入到显示技术的应用中变得越来越重要。微观结构的一个基本特征是它们的机械性能。迄今为止，在操作结构上执行这些属性的可重复和准确的测量已被证明是极其困难的。这种监测将使得能够可靠地表征制造期间的制造步骤对机械性能的影响。此外，它还可以随时评估包装、环境条件和连续使用对机械完整性的影响。该项目的重点是监测这些机械性能（密度，刚度等）。使用非接触式光学技术。这种方法使用光信号在材料中产生超声波响应，并且该响应被光学监控。该响应的复杂性使得能够通过涉及精心构造的数值数学反演技术的曲线拟合来确定机械材料特性。对于简单的结构，响应可以解析建模，并将该解析模型进行数值反演。对于更复杂的结构，可靠的计算机建模对于正演和反演分析都是必不可少的。因此，该项目有平行股检查简单和更复杂的微观结构，并广泛使用有限元建模技术，在适当的情况下，以加强实验技术。此外，对于非常简单的结构，测量方法将参考我们在国家物理实验室的合作伙伴开发的基于接触的系统。我们已经证明了在较大规模的几何简单的结构的基本原则，并有信心，在1%的顺序的重复性是可以实现的。然而，将该技术扩展到微结构确实在实现千兆赫带宽超声激发（其中波长与结构尺寸相当）和检测以及容纳更复杂的结构伪影方面提出了重大的研究挑战，此外还产生了微尺度检测和激发光学器件。