Abstract
An LC wireless passive pressure sensor based on a single-crystalline magnesium oxide (MgO) MEMS processing technique is proposed and experimentally demonstrated for applications in environmental conditions of 900 °C. Compared to other high-temperature resistant materials, MgO was selected as the sensor substrate material for the first time in the field of wireless passive sensing because of its ultra-high melting point (2800 °C) and excellent mechanical properties at elevated temperatures. The sensor mainly consists of inductance coils and an embedded sealed cavity. The cavity length decreases with the applied pressure, leading to a monotonic variation in the resonant frequency of the sensor, which can be retrieved wirelessly via a readout antenna. The capacitor cavity was fabricated using a MgO MEMS technique. This MEMS processing technique, including the wet chemical etching and direct bonding process, can improve the operating temperature of the sensor. The experimental results indicate that the proposed sensor can stably operate at an ambient environment of 22–900 °C and 0–700 kPa, and the pressure sensitivity of this sensor at room temperature is 14.52 kHz/kPa. In addition, the sensor with a simple fabrication process shows high potential for practical engineering applications in harsh environments.
Highlights
Tan et al proposed an LC wireless passive sensor based on low- and high-temperature co-fired ceramics (LTCC), an imidization process, and screen-printing technology for simultaneous multi-parameter sensing, and demonstrated that the sensor can work in an ambient environment of 25–200 ◦ C, 24–90% RH, and 70–220 kPa, with a pressure sensitivity value of 3.25 kHz/kPa [24]
The sensor was placed on the Chengdu Jiangtai Co., Ltd., Chengdu, China) was used to verify the feasibility and perplaced thewith ceramic tray withensured a hole, which ensured that the temperature andaccurately pressure ceramicon tray a hole, which that the temperature and pressure were formance of the wireless passiveapplied pressure sensor, asAshown in
An LC wireless passive pressure sensor based on a single-crystalline magnesium oxide (MgO) MEMS processing technique was proposed and experimentally demonstrated for applications in high-temperature environments up to 900 ◦ C
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Wireless passive inductive capacitive (LC) resonance sensors are good candidates in high-temperature or rotation environments because of their lower operating frequency, simple manufacturing, and near-field coupling distance [16]. Tan et al proposed an LC wireless passive sensor based on LTCC, an imidization process, and screen-printing technology for simultaneous multi-parameter sensing, and demonstrated that the sensor can work in an ambient environment of 25–200 ◦ C, 24–90% RH, and 70–220 kPa, with a pressure sensitivity value of 3.25 kHz/kPa [24]. The more, the maximum deformation of the diaphragm and the pressure measurement range planar inductance coils and reader antenna of the resonant sensor are coupled when the are restrained by the structure parameters of the sensor.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
