Design and application of a wireless, passive, resonant-circuit environmental monitoring sensor

Abstract A wireless, passive, remote query sensor platform is presented capable of monitoring the complex permittivity of a surrounding medium, temperature, humidity, and pressure. The sensor is a planar two-dimensional inductor–capacitor circuit, of scaleable-size, that resonates at a characteristic frequency the value of which is dependent upon the parameters of interest. The resonant frequency of the sensor is detected remotely with one or a pair of loop antennas by measuring the impedance or voltage spectrum of the antenna(s), with the environmental parameters of interest then calculated from the measured resonant frequency. The wireless, remote query nature of the platform enables the LC sensor to monitor the environmental conditions from within sealed opaque containers. The paper describes the operational principles, design criteria, illustrative applications, and performance limitations of the sensor platform.

[1]  Yasuhiro Shimizu,et al.  Theoretical studies on the impedance-humidity characteristics of ceramic humidity sensors , 1985 .

[2]  S. Drost,et al.  Optimization of the geometry of gas-sensitive interdigital capacitors , 1991 .

[3]  Koji Asami,et al.  Dielectric spectroscopy of biological cells , 1996 .

[4]  Gijsbertus J.M. Krijnen,et al.  A micromachined pressure/flow-sensor , 1999 .

[5]  Francine S. Bovard,et al.  Electrochemical impedance spectroscopy of electrocoated aluminium food cans , 1995 .

[6]  K. G. Ong,et al.  A resonant printed-circuit sensor for remote query monitoring of environmental parameters , 2000 .

[7]  Jun Guo,et al.  A monolithically integrated surface micromachined touch mode capacitive pressure sensor , 2000 .

[8]  Enrico Traversa,et al.  Ceramic sensors for humidity detection: the state-of-the-art and future developments , 1995 .

[9]  J. Fraden,et al.  Handbook of Modern Sensors: Physics, Designs, and Applications, 2nd ed. , 1998 .

[10]  Anton Leidl,et al.  A new SO2 sensor system with SAW and IDC elements , 1996 .

[11]  K. Potje-Kamloth,et al.  A new carbon monoxide sensor using a polypyrrole film grown on an interdigital-capacitor substrate , 1997 .

[12]  Florian Mansfeld,et al.  Use of electrochemical impedance spectroscopy for the study of corrosion protection by polymer coatings , 1995 .

[13]  K. Najafi,et al.  A passive humidity monitoring system for in-situ remote wireless testing of micropackages , 2000, Proceedings IEEE Thirteenth Annual International Conference on Micro Electro Mechanical Systems (Cat. No.00CH36308).

[14]  C A Grimes,et al.  Remote query measurement of pressure, fluid-flow velocity, and humidity using magnetoelastic thick-film sensors. , 2000, Sensors and actuators. A, Physical.

[15]  Clayton R. Paul.  Analysis of linear circuits , 1989 .

[16]  J. English,et al.  Wireless micromachined ceramic pressure sensors , 1999, Technical Digest. IEEE International MEMS 99 Conference. Twelfth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.99CH36291).

[17]  C. Grimes,et al.  A remote query magnetoelastic pH sensor. , 2000, Sensors and actuators. B, Chemical.

[18]  C A Grimes,et al.  A remote query magnetostrictive viscosity sensor. , 2000, Sensors and actuators. A, Physical.

[19]  Dai Gil Lee,et al.  Analysis of dielectric sensors for the cure monitoring of resin matrix composite materials , 1996 .

[20]  R. A. Waldron,et al.  Theory of a Strip-Line Cavity for Measurement of Dielectric Constants and Gyromagnetic-Resonance Line-Widths , 1964 .

[21]  Craig A. Grimes,et al.  Remote query fluid-flow velocity measurement using magnetoelastic thick-film sensors (invited) , 2000 .

[22]  Hanns-Erik Endres,et al.  A capacitive CO2 sensor system with suppression of the humidity interference , 1999 .

[23]  E. Gheorghiu,et al.  Real-time monitoring of yeast cell division by dielectric spectroscopy. , 1999, Biophysical journal.

[24]  P. Thoma,et al.  A Capacitance Humidity-Sensing Transducer , 1979 .

[25]  K.W. Misevich,et al.  Capacitive Humidity Transducer , 1969, IEEE Transactions on Industrial Electronics and Control Instrumentation.