EAGER: Ultra-Sensitive Resonant MEMS Magnetometers with Internal Thermal-Piezoresistive Amplification

EAGER：具有内部热压阻放大功能的超灵敏谐振 MEMS 磁力计

• 批准号: 1345161
• 负责人: Siavash Pourkamali Anaraki
• 金额: $ 15.06万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-10-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1345161&HistoricalAwards=false
• 关键词: EAGER; Ultra; Sensitive; Resonant; MEMS

Objective: The objective of this project is to explore the potentials of the internal thermal piezoresistive quality factor and displacement amplification effect in silicon resonant microstructures for realization of ultra-high sensitivity and low noise magnetometers. MEMS magnetometers consisting of silicon based resonant microstructures with integrated insulated metallic traces will be designed and fabricated. The performance of the fabricated devices will be characterized and the effect of internal amplification offered by the strategically designed silicon structure on sensitivity and noise level of the magnetometers will be investigated. Intellectual Merit: The proposed MEMS magnetometers operate based on harvesting and internally amplifying the Lorentz force (force applied to a current carrying conductor in a magnetic field). Extremely high effective quality factors (Q) up to ~1000X larger than the intrinsic mechanical Q of the resonator have been demonstrated using the internal thermal-piezoresistive amplification effect. It is expected that such high Q values can amplify vibration amplitude resulting from the Lorentz force without adding to the electronic noise level leading to superior performance for the proposed sensors. Preliminary analysis show that noise levels in the pT/Hz1/2 range should be within reach, which is comparable to that offered by some of the most sophisticated technologies available. The proposed effort combines the simplicity, small size, and ease/low cost of fabrication of silicon-based MEMS magnetometers with unprecedentedly high sensitivities. The potential outcome will be small size, low cost and easy to use ultra-sensitive magnetometers that circumvent shortcomings of other existing technologies such as the need for cryogenic cooling, integration of exotic materials, large size and high power consumption. Broader Impact: Highly sensitive, small size, and easy to use magnetometers can have transformative effects in various areas including biology and biomedical engineering, geology and mineral/oil exploration, as well as surveillance and defense (through wall/underground imaging and target tracking). For example, arrays of SQUIDs requiring cryogenic cooling are currently used for mapping brain activity by monitoring small magnetic fields (tens to thousands of femotTesla) resulting from firing of neurons in the brain. Small size and convenience offered by the proposed microscale devices can leads to significant advances in brain mapping and enable development of advanced portable brain monitoring devices. On the educational front, one postdoctoral researcher, one PhD level graduate student and up to two undergraduate researchers will be trained and directly involved in the research activities. Results from the research activities will serve as interesting course materials enriching the PIs ongoing courses in MEMS and microsystems. The experience gained by the PI during the course of this project will provide him with a highly valuable insight in a new field of research that will be transferred to current and future students.

目的：本计画旨在探讨硅谐振微结构内部热压阻品质因数与位移放大效应之潜力，以实现超高灵敏度与低杂讯之磁力计。将设计和制造由硅基谐振微结构和集成绝缘金属迹线组成的MEMS磁力计。制造的设备的性能将被表征，并将研究由战略设计的硅结构提供的内部放大对磁力计的灵敏度和噪声水平的影响。智力优势：所提出的MEMS磁力计基于收集和内部放大洛伦兹力（在磁场中施加到载流导体的力）来操作。使用内部热压阻放大效应，已经证明了比谐振器的固有机械Q大~ 1000倍的极高的有效品质因数（Q）。预期这样的高Q值可以放大由洛伦兹力产生的振动幅度，而不增加电子噪声水平，从而导致所提出的传感器的上级性能。初步分析表明，pT/Hz 1/2范围内的噪声水平应该是可以达到的，这与现有的一些最先进的技术所提供的噪声水平相当。所提出的努力结合了硅基MEMS磁力计的简单性、小尺寸和容易/低成本制造，具有前所未有的高灵敏度。潜在的结果将是小尺寸、低成本和易于使用的超灵敏磁力计，这些磁力计克服了其他现有技术的缺点，例如需要低温冷却、集成外来材料、大尺寸和高功耗。更广泛的影响：高灵敏度、小尺寸和易于使用的磁力计可以在各个领域产生变革性影响，包括生物学和生物医学工程、地质学和矿物/石油勘探以及监视和防御（通过墙壁/地下成像和目标跟踪）。例如，需要低温冷却的SQUID阵列目前用于通过监测大脑中神经元放电产生的小磁场（数万至数千femotTesla）来映射大脑活动。所提出的微尺度设备提供的小尺寸和便利性可以导致脑映射的显著进步，并且使得能够开发先进的便携式脑监测设备。在教育方面，一名博士后研究员，一名博士水平的研究生和最多两名本科生研究员将接受培训，并直接参与研究活动。研究活动的结果将作为有趣的课程材料，丰富了PI正在进行的MEMS和微系统课程。PI在这个项目的过程中获得的经验将为他提供一个非常有价值的洞察力，在一个新的研究领域，将转移到当前和未来的学生。