SBIR PHASE I: High Performance Nondestructive Evaluation System Using a Giant Magnetoresistance Sensor Array

这个小企业创新研究第一阶段项目将开发一种基于含有巨磁电阻（GMR）材料元件的传感器的无损评估（NDE）方法。在建筑物、桥梁和飞机部件中使用的金属结构的异常和应力的无损检测需要新的技术。目前基于目视检查、涡流检查、x射线摄影和声发射的技术在检查能力、检查速度和检查成本方面受到限制。GMR效应导致了具有极高信噪比的磁场传感器的发展，能够在环境条件下检测极弱的磁场。用于形成这些传感器的微加工技术非常适合于具有广泛几何形状的低成本传感器阵列的构建。磁性方法已被证明能够检测异常，如裂纹，并估计钢构件焊接内部和周围的应力。通过适当的传感器设计，可以使用磁强计获得有关部件内部结构和应力的高分辨率三维信息。该项目将开发一种基于GMR材料的传感器阵列，并将其与仪器和分析概念相结合，从而可以对金属部件进行三维成像。将开发一种预测能力，以评估用NDE系统分析的部件的机械完整性。一种简单易用、现场便携的金属结构无损检测技术将有许多应用，包括桥梁、建筑物和飞机的检测。柔性传感器可以检测各种不同形状的样品。快速、高分辨率的图像将使实际的成本效益检查成为可能。预测机械退化的能力将为哪些结构严重受损以及哪些结构可以继续使用提供关键的见解。传感器将是简单和廉价的制造和所需的支持电子是可用的，所以，除了高性能，它应该有可能在一个合理的成本制造系统。

9560415 Tiernan This Small Business Innovation Research Phase I project will develop a nondestructive evaluation (NDE) method based on sensors containing elements of giant magnetoresistance (GMR) material. New techniques are needed for the NDE of anomalies and stresses in metal structures used in buildings, bridges, and aircraft components. Current techniques based on visual inspections, eddy current, X-ray radiography, and acoustic emissions suffer from limitations in inspection capability, speed of inspection, and cost of inspection. The GMR effect has resulted in the development of magnetic field sensors with extremely high signal-to-noise levels capable of detecting extremely weak magnetic fields under ambient conditions. The microfabrication techniques used to form these sensors are well suited to the construction of low cost sensor arrays with a wide range of geometries. Magnetic methods have been shown to be capable of detecting anomalies such as cracks and for estimating the stresses in and around welds in steel components. With proper sensor design it is possible to use magnetometry to obtain high resolution, three-dimensional information concerning the internal structure and stress of a component. This project will develop a sensor array based on GMR material and combine it with instrumentation and analytical concepts that will permit the 3-D imaging of metal components. A predictive capability will be developed to assess the mechanical integrity of components analyzed with the NDE system. A simple-to-use, field-portable NDE technique for metallic structures would find many applications including the inspection of bridges, buildings, and aircraft. The flexible sensor would permit the inspection of a wide range of different sample shapes. Rapid, high resolution images would permit practical cost effective inspections. The ability to predict mechanical degradation would provide critical insight concerning which structures are severely damaged and which can rem ain in service. The sensors will be simple and inexpensive to fabricate and the support electronics required is available so, in addition to high performance, it should be possible to manufacture the system at a reasonable cost.