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Review of Research Status and Development Trends of Wireless Passive LC Resonant Sensors for Harsh Environments.

Li C, Tan Q, Jia P, Zhang W, Liu J, Xue C, Xiong J - Sensors (Basel) (2015)

Bottom Line: Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited.Consequently, these devices have become the focus of many current research studies.The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China. flanklichen@163.com.

ABSTRACT
Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited. Wireless passive LC resonant sensors offer long service life and can be suitable for harsh environments because they can transmit signals without battery power or wired connections. Consequently, these devices have become the focus of many current research studies. This paper addresses recent research, key technologies, and practical applications relative to passive LC sensors used to monitor temperature, pressure, humidity, and harmful gases in harsh environments. The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

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Related in: MedlinePlus

Wireless passive LC ceramic pressure sensor.
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sensors-15-13097-f003: Wireless passive LC ceramic pressure sensor.

Mentions: For silicon or silicon-on-insulator materials, the mechanical properties easily deteriorate, and the leakage current across the junctions drastically changes with increasing temperature, which limits the operating temperature range of the sensors based on these materials. Ceramic is a good insulator and is chemically stable in high-temperature environments, which enables sensors based on ceramics capable of wide application in high-temperature environments. The fabrication process of high-temperature passive LC ceramic pressure sensors is simple, which includes milling, tape casting, cutting, punching, screen printing, stacking, lamination, and firing. A typical structure of an LC ceramic pressure sensor is shown in Figure 3. In 1999, the team of Professor M. G Allen at the Georgia Institute of Technology pioneered and developed a wireless passive LC pressure sensor based on low-temperature co-fired ceramic (LTCC) technology. Experimental results demonstrated that the average accuracy and sensitivity of this sensor are 24 mbar and −141 kHz/bar, respectively, at 400 °C within a pressure range of 0 to 7 bar [13,14,15]. In 2009, a research team in Novi Sad, Serbia, proposed a better structural model. The improved structural design and the use of LTCC material made this embedded structural sensor suitable for high-temperature and chemically aggressive environments [16,17]. In 2013, researchers at the North University of China, which has been committed to developing wireless, high-temperature passive LC ceramic pressure sensors, introduced a unique screen-printing process involving a sacrificial layer of ESL 4900 to prevent deformation of a capacitive embedded cavity during lamination and sintering. This approach improved the flatness of the sensor cavity and led to better performance. The sensitivity of LTCC pressure sensors can reach −344 kHz/bar [18], the sensitivity of sensors based on high-temperature cofired ceramic (HTCC) can reach 860 Hz/bar [19,20], and sensors based on zircon ceramics can maintain stable operation at 800 °C for 30 min [21]. In 2014, researchers at the North University of China proposed improved structural models based on the LTCC, HTCC, and thick-film integrated technologies to improve the performance parameters (e.g., sensitivity, pressure range, operating temperature range, and coupling distance between the sensor and antenna) in harsh environments. Experimental results demonstrated good performance of these improved sensors, namely, sensitivity of up to 13 kHz/kPa, maximum working distance of up to 5 cm, maximum working pressure of up to 60 bar, and consistently low repeatability and hysteresis errors [22,23,24,25,26].


Review of Research Status and Development Trends of Wireless Passive LC Resonant Sensors for Harsh Environments.

Li C, Tan Q, Jia P, Zhang W, Liu J, Xue C, Xiong J - Sensors (Basel) (2015)

Wireless passive LC ceramic pressure sensor.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4507668&req=5

sensors-15-13097-f003: Wireless passive LC ceramic pressure sensor.
Mentions: For silicon or silicon-on-insulator materials, the mechanical properties easily deteriorate, and the leakage current across the junctions drastically changes with increasing temperature, which limits the operating temperature range of the sensors based on these materials. Ceramic is a good insulator and is chemically stable in high-temperature environments, which enables sensors based on ceramics capable of wide application in high-temperature environments. The fabrication process of high-temperature passive LC ceramic pressure sensors is simple, which includes milling, tape casting, cutting, punching, screen printing, stacking, lamination, and firing. A typical structure of an LC ceramic pressure sensor is shown in Figure 3. In 1999, the team of Professor M. G Allen at the Georgia Institute of Technology pioneered and developed a wireless passive LC pressure sensor based on low-temperature co-fired ceramic (LTCC) technology. Experimental results demonstrated that the average accuracy and sensitivity of this sensor are 24 mbar and −141 kHz/bar, respectively, at 400 °C within a pressure range of 0 to 7 bar [13,14,15]. In 2009, a research team in Novi Sad, Serbia, proposed a better structural model. The improved structural design and the use of LTCC material made this embedded structural sensor suitable for high-temperature and chemically aggressive environments [16,17]. In 2013, researchers at the North University of China, which has been committed to developing wireless, high-temperature passive LC ceramic pressure sensors, introduced a unique screen-printing process involving a sacrificial layer of ESL 4900 to prevent deformation of a capacitive embedded cavity during lamination and sintering. This approach improved the flatness of the sensor cavity and led to better performance. The sensitivity of LTCC pressure sensors can reach −344 kHz/bar [18], the sensitivity of sensors based on high-temperature cofired ceramic (HTCC) can reach 860 Hz/bar [19,20], and sensors based on zircon ceramics can maintain stable operation at 800 °C for 30 min [21]. In 2014, researchers at the North University of China proposed improved structural models based on the LTCC, HTCC, and thick-film integrated technologies to improve the performance parameters (e.g., sensitivity, pressure range, operating temperature range, and coupling distance between the sensor and antenna) in harsh environments. Experimental results demonstrated good performance of these improved sensors, namely, sensitivity of up to 13 kHz/kPa, maximum working distance of up to 5 cm, maximum working pressure of up to 60 bar, and consistently low repeatability and hysteresis errors [22,23,24,25,26].

Bottom Line: Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited.Consequently, these devices have become the focus of many current research studies.The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Instrumentation Science & Dynamic Measurement, Ministry of Education, North University of China, Tai Yuan 030051, China. flanklichen@163.com.

ABSTRACT
Measurement technology for various key parameters in harsh environments (e.g., high-temperature and biomedical applications) continues to be limited. Wireless passive LC resonant sensors offer long service life and can be suitable for harsh environments because they can transmit signals without battery power or wired connections. Consequently, these devices have become the focus of many current research studies. This paper addresses recent research, key technologies, and practical applications relative to passive LC sensors used to monitor temperature, pressure, humidity, and harmful gases in harsh environments. The advantages and disadvantages of various sensor types are discussed, and prospects and challenges for future development of these sensors are presented.

Show MeSH
Related in: MedlinePlus