COLLABORATIVE RESEARCH: SENSORS: Inductively Coupled Flexural Wave Resonator Sensing

微电子机械系统(MEMS)已经发展成为众多的物理传感器。虽然单个传感器已经证明了这项技术的可行性，但许多应用需要许多不同传感器的阵列。提出了谐振式传感器阵列监测的有效方法，包括监测系统与微机械传感器阵列的集成。已经开发了用于监测温度、压力、加速度、旋转、应力、化学物质、生物制剂和其他物理参数的微型系统。通常需要多个位置的多个参数或单个参数的信息。将开发一种同时探测多个传感器的方法。该方法基于谐振式传感电路的能量吸收。能量吸收技术在光谱学中是众所周知的，但还没有被应用于传感器阵列。将使用类似的技术来研究传感阵列的能量吸收，而不是研究材料中原子跃迁的能量发射和吸收。最初集成到传感系统中的传感器将是弯曲平板谐振器。之所以选择这种传感器，是因为它已被证明可用于化学和生物试剂，可在液体和蒸气环境中工作，具有兆赫范围的谐振频率，并且可以使用标准技术轻松进行微制造。谐振传感器将被制造成具有在电感-电容电路的电吸收频率内的谐振频率。电能将感应耦合到电路中，并驱动传感器进入谐振状态。电能和机械能的吸收将有效地改变驱动电路的阻抗，最大变化发生在传感器的机械谐振处。共振频率会随着结构的质量和应力的变化而变化。这是通过在谐振表面涂覆薄膜吸附层来使其对不同的试剂敏感。将多个传感器组合在一起将产生一种吸收光谱，可用于通过FM光谱技术监测共振。该系统将扫描频率并锁定到每个共振，记录值，然后继续扫描到下一个共振，就像汽车收音机上的扫描按钮一样。这项研究的智力价值在于发展了无线传感器询问技术，并将这些技术应用于需要传感器的跨学科问题。本研究的目标是开发一种基于电感耦合吸收电能的谐振式MEMS传感器阵列的无线遥测系统。这些传感器和传感系统将用作化学蒸气和生化检测器，以及应变、湿度、压力和加速度传感器。这项研究的更广泛影响是传感器技术与微电子机械系统和射频识别的持续整合。这项工作将为建立一个被动监测参数、通过电气或机械手段存储信息并在探测时传输数据的系统奠定基础。这项研究将增加研究者在系统性能评估方面的知识基础和专业知识，并将通过各自的大学课程和学生研究计划影响研究生和本科生的教育。这项研究的多学科特点将需要机械、电气和化学工程的研究生相互作用来解决所述问题。

Microelectromechanical systems (MEMS) have been developed into numerous physical sensors. While individual sensors have demonstrated the viability of the technology, many applications require arrays of many different sensors. Development of efficient methods to monitor resonant sensor arrays is proposed including the integration of the monitoring system with micromechanical sensor arrays. Microsystems for monitoring temperature, pressure, acceleration, rotation, stress, chemicals, biological agents and other physical parameters have been developed. Often information for more than one parameter or single parameters at numerous locations is required. A method to probe numerous sensors simultaneously will be developed. The method is based on energy absorption of resonant sensing circuits. Energy absorption techniques are well known in spectroscopy but have not been applied to sensor arrays. Rather than look at the energy emission and absorption of atomic transitions in materials, energy absorption of sensing arrays will be investigated using similar techniques. The sensor that will initially be integrated into the sensing system will be the flexural plate resonator. This sensor was chosen because it has been demonstrated for both chemical and biological agents, operates in liquid and vapor environments, has resonant frequencies in the megahertz range and can be easily microfabricated using standard techniques. The resonant sensor will be manufactured to have a resonant frequency that is within the electrical absorption frequencies of an inductor-capacitor circuit. Electrical energy will inductively couple into the electrical circuit and drive the sensor into resonance. The absorption of the electrical and mechanical energy will effectively change the impedance of the driving circuit, the maximum change being at the mechanical resonance of the sensor. The resonant frequency will vary with changes in the mass and stresses of the structure. This is made sensitive to different agents by coating the resonant surface with thin film sorption layers. Combining numerous sensors will create an absorption spectrum that can be used to monitor resonances by FM spectroscopy techniques. The system will sweep the frequency and lock to each resonance, record the value then continue the sweep to the next resonance, much like the scan button on car radios. The intellectual merit of this research is the development of wireless sensor interrogation technology and the application of these technologies to interdisciplinary problems that require sensors. The goal of this research is to develop a wireless telemetry system for remotely interrogating arrays of resonant MEMS sensors based on the absorption of electrical energy through inductive coupling. These sensors and sensing system would have applications as chemical vapor and biochemical detectors, as well as strain, humidity, pressure and acceleration sensors. The broader impact of this research is the continued integration of sensor technology with microelectromechanical systems and radio frequency identification. This work will lay the foundation to create a system that will passively monitor parameters, store the information through electrical or mechanical means and transmit the data when probed. This research will increase the investigators knowledge base and expertise in system performance assessment, and this research will also impact the education of both graduate and undergraduate students through the respective university curriculum and student research programs. The multi-disciplinary features of this research will require graduate students of mechanical, electrical and chemical engineering to interact to solve the stated problem.