Passive Hybrid MEMS for High-Temperature Telemetric Measurements
Passive Hybrid MEMS for High-Temperature Telemetric Measurements
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DOI：
10.1109/tim.2009.2038026
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发表时间：
2010-05-01
影响因子：
5.6
通讯作者：
Serpelloni, Mauro
中科院分区：
文献类型：
--
作者：
Marioli, Daniele;Sardini, Emilio;Serpelloni, Mauro
非接触式传感器代表了在恶劣环境中进行高温测量的有吸引力的解决方案，在这些环境中，不适合使用电缆，并且温度值超出了有源电子电路所允许的温度值。温度传感器在温度控制和调节的自动化过程中有着广泛的应用。本文介绍了一种适用于高温测量的无源传感装置，该装置由微加工的温度敏感可变电容器和设计用于高温环境的平面电感组成。另一个读出电感器与平面电感器一起构成遥测系统，遥测系统是一个耦合变压器，读出器连接到测量电子设备。所提出的无源混合微机电系统（MEMS）由连接在平面电感上的交叉电容组成。混合传感器的工作原理是一种LC谐振电路，其中交叉电容代表电容，平面电感代表电感。温度诱导交叉电容的导电电极向固定电极位移，从而实现温度敏感的可变电容。分析了可变电容与平面电感的等效电路方案。已经测试了两种依赖于频率变化输出的遥测测量方法。整个系统已在实验室进行了测试，并报告了一些结果。最后，制作了传感器原型，并成功地表征了高达330摄氏度的温度，作为通过无源无线通信进行温度传感概念的证明。提出的遥测温度系统可以成为恶劣和复杂环境下效率监测和预测性维护的解决方案，从而消除了对物理接触、有源元件或电源的需求，这些都不能承受恶劣环境。
A contactless sensor represents an attractive solution for high-temperature measurements in harsh environments, where the use of cables is not suitable, and where the temperature values are beyond those permitted by active electronic circuits. Temperature sensors have a wide variety of applications in automated processes for temperature control and regulation. This paper describes a passive sensing device suitable for high-temperature measurements consisting of a microfabricated temperature-sensitive variable capacitor and a planar inductor designed for high-temperature environments. Another readout inductor constitutes, together with the planar inductor, a telemetric system, which is a coupled transformer with the readout connected to the measurement electronics. The proposed passive hybrid microelectromechanical systems (MEMS) consists of an interdigitated capacitor bonded to the planar inductor. The hybrid sensor behaves as an LC resonant circuit in which the interdigitated capacitor represents the capacitance and the planar inductor is the inductance. The temperature induces a displacement of the conductive electrodes of the interdigitated capacitor toward the fixed electrodes realizing a temperature-sensitive variable capacitor. An equivalent circuit scheme of the variable capacitor and the planar inductor has been analyzed. Two telemetric measurement methods, relying on a frequency variation output, have been tested. The whole system has been tested in the laboratory, and several results are reported. Finally, the sensor prototype was fabricated and successfully characterized up to 330 degrees C as a proof of concept of temperature sensing through passive wireless communication. The proposed telemetric temperature system can be a solution for efficiency monitoring and predictive maintenance for harsh and complex environments, thereby eliminating the need for physical contacts, active elements, or power supplies, which cannot withstand harsh environments.