PFI-TT: Multi-Frequency Acoustic Device for Rapid Infrastructure Damage Diagnostics

创新技术转化伙伴关系（PFI-TT）项目更广泛的影响/商业潜力是使用更可靠和更具成本效益的健康监测手段确保关键民用基础设施（如管道和桥梁）的安全运行。随着极端天气事件的数量和强度不断增加，老化基础设施的性能令人担忧;意外故障会导致交通严重中断，并对人类生活和环境产生负面影响。幸运的是，声发射可以“倾听”基础设施中的裂缝，并在可见之前检测出缺陷。该创新是建立一个低成本和低功耗的声发射设备，用于检测具有数百个传感器的基础设施，并在最早的状态下检测损坏的开始。传感器的技术是微机电系统（MEMS）。大规模制造的MEMS声发射设备可以通过从基础设施收集大量可靠的数据将技术提升到一个新的水平。其目的是使用大量传感器对基础设施进行检测，这些传感器可以快速了解结构状态和安全性。当美国的大多数结构系统都装有MEMS声发射装置时，可以在最早阶段检测到故障的发生，并采取必要的预防措施，防止更大的费用。该项目旨在将多频MEMS声发射装置与噪声隔离能力集成，并将其转变为可现场部署的技术。声发射是一种无损评价方法，基于检测由于活动缺陷或运动（如裂纹扩展或滑坡）而传播的弹性波。它是众所周知的检测损伤的开始，精确定位其位置，定性评估损伤的严重程度，并使用模式识别工具分类的损伤模式。然而，目前的声发射传感器体积庞大，价格昂贵，受背景噪声的影响很大;它们需要复杂的后处理来理解信号表征，这延迟了决策过程。MEMS传感器使用微机械加工技术制造，其允许具有可重复的固有特性的大规模制造。MEMS声发射装置将由多个超窄带宽MEMS压电谐振器连接在一个阵列中，这样，总的响应被放大的建设性干扰仔细选择的频率。该信号可以很容易地分解成其频率，以了解频率依赖的损伤模式和严重程度。为了区分人工噪声源和主动结构缺陷，MEMS声发射器件将与宽带弹性超材料相结合，以阻止不必要的信号，从而实现减少数据的无线传输。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this Partnerships for Innovation-Technology Translation (PFI-TT) project is to ensure the safe operation of critical civil infrastructure (such as pipelines and bridges) using a more reliable and cost-effective means of monitoring their health. Subjected to an increasing number and magnitude of extreme weather events, the performance of aging infrastructure is a concern; Unexpected failures cause significant disruption in transportation and negatively influence human lives and the environment. Fortunately, acoustic emission, can “listen” for cracks in the infrastructure and detect defects before they are visible. The innovation is to build a low-cost and low-power acoustic emission device for instrumenting infrastructures with hundreds of sensors and detecting the damage initiation at the earliest state. The technology for the sensors is micro-electro-mechanical systems, MEMS. Mass manufactured MEMS acoustic emission devices may take the technology to the next level by collecting big and reliable data from infrastructures. The aim is to instrument infrastructures with voluminous sensors that can rapidly inform about the structural state and safety. When the majority of structural systems in the US are instrumented with MEMS acoustic emission devices, the initiation of failure can be detected at its earliest stage and necessary precautions can be taken, preventing greater expenses. The proposed project aims to transition multi-frequency MEMS acoustic emission devices integrated with noise isolation capability into a field-deployable technology. Acoustic Emission is a nondestructive evaluation method based on detecting the propagating elastic waves due to active defects or movements such as crack growth or landslides. It is well-known for detecting the initiation of damage, pinpointing its location, qualitatively assessing the severity of damage, and classifying the damage mode using pattern recognition tools. However, current acoustic emission sensors are bulky, expensive, and significantly influenced by background noise; They require complex post-processing to understand the signal characterization, which delays the decision-making process. MEMS sensors are manufactured using micromachining techniques, that allow mass manufacturing with repeatable intrinsic characteristics. MEMS acoustic emission devices will be built by multiple super-narrow bandwidth MEMS piezoelectric resonators connected in an array such that the total response is amplified by the constructive interference of carefully selected frequencies. The signal can easily be decomposed into its frequencies in order to understand the frequency-dependent damage modes and severity. To distinguish artificial noise sources from active structural defects, the MEMS acoustic emission device will be coupled with broadband elastic metamaterials to block unwanted signals for the reduced-data wireless transfer.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.