Non-Contact Experimental Technique to Characterize Interfacial Crack Propagation in Nano-Scale and Micro-Scale Thin Films

薄膜界面脱层是一个重要的可靠性问题，在广泛的应用。虽然大量的界面脱层是由疲劳载荷引起的，但现有文献没有充分解决这个问题，特别是对于纳米尺度的薄膜。该提案旨在开发一种创新的疲劳脱层测试，可用于监测和表征纳米尺度以及微米尺度薄膜的界面脱层传播。所提出的测试具有几个智能方面：它使用纳米级金属迹线来监测分层传播;它使用电磁致动来提供分层传播所需的驱动力，因此测试方法不需要任何夹具来施加负载;使用放置在外部磁场中并具有原位裂纹扩展能力的悬臂梁阵列，提出的测试技术将是界面疲劳裂纹测试的一个重大进步。纳米级薄膜正越来越多地用于广泛的应用中，例如固态器件、集成电子元件、传感器、MEMS/NEMS、用于更好的光传输的抗反射光学膜、显示技术中的导电膜、太阳能电池中的薄膜涂层、用于介质存储的磁性涂层以及用于空间探索的柔性和可弯曲透镜。拟议的研究将对它们的可靠性产生重大影响。 研究方法和研究结果将被整合到研究生和本科教育中。 此外，学生将接触到纳米尺度的薄膜制造和测试。 研究方法和结果将发表在技术期刊上，并在会议上介绍，以达到广泛的受众。

Thin film interfacial delamination is an important reliability concern in a wide range of applications. Although a significant amount of interfacial delamination is caused by fatigue loading, existing literature has not adequately addressed this topic, especially for nano-scale thin films. This proposal aims to develop an innovative fatigue delamination test that can be used to monitor and characterize interfacial delamination propagation for nano-scale as well as micro-scale thin films. The proposed test has several intellectual aspects: it uses nano-scale metal traces to monitor the delamination propagation; it uses electromagnetic actuation to provide the driving force needed for delamination propagation, and thus the test method does not require any fixtures to apply loads; using an array of cantilevers placed in an external magnetic field and with in-situ crack propagation capabilities, the proposed test technique will be a significant advancement in interfacial fatigue crack testing. Nano-scale thin films are being increasingly used in a wide range of applications such as solid-state devices, integrated electronic components, sensors, MEMS/NEMS, antireflective optical films for better light transmission, conductive films in display technologies, thin-film coating in solar cells, magnetic coatings for media storage, and flexible and bendable lenses for space exploration. The proposed research will have a strong impact on their reliability. The research approach and the findings will be integrated in graduate and undergraduate education. Also, students will get exposure to nano-scale thin film fabrication and testing. The research methodology and results will be published in technical journals and presented in conferences to reach a wide-ranging audience.