A Remote Query Pressure Sensor Based on Magnetic Higher Order Harmonic Fields

The design and fabrication of a wireless, passive pressure sensor based on the change in magnetic higher order harmonic fields is described. The sensor was made of an airtight pressure chamber with two opposite membranes: a rigid membrane attached to a magnetically soft ferromagnetic strip (sensing element) and a flexible membrane attached to a permanent magnetic strip (biasing element). The flexible membrane of the chamber deflected with changing pressure, thus varying the separation distance between the sensing and biasing elements. The change in separation distance in turn altered the biasing field experienced by the sensing element, varying the pattern of its magnetic higher order harmonic fields allowing remote pressure monitoring through a magnetic coil. In this work, different materials were used to fabricate the flexible membranes for sensors of different dynamic ranges. Experimental results showed the shifts in magnetic higher order harmonic fields were linear for all sensors, but with different sensitivity depending on the elasticity of the flexible membrane. The novelty of this sensor is its wireless, passive nature, which is ideal for applications where wire connections are prohibited. In addition, the simple sensor design reduces cost, allowing disposable use. Potential applications of such a sensor technology include long-term structural monitoring (concrete, asphalt) and in vivo pressure monitoring inside the human body.

[1]  L. M. Sheppard.  Automotive sensors improve driving performance , 1992 .

[2]  G. E. Loeb,et al.  Cuff electrodes for chronic stimulation and recording of peripheral nerve activity , 1996, Journal of Neuroscience Methods.

[3]  Jiang Zhuangde,et al.  A novel high temperature pressure sensor on the basis of SOI layers , 2003 .

[4]  Chou-Ching K. Lin,et al.  An implantable capacitive pressure sensor for biomedical applications , 2007 .

[5]  B.J. Hosticka,et al.  A programmable intraocular CMOS pressure sensor system implant , 2001, Proceedings of the 26th European Solid-State Circuits Conference.

[6]  Craig A. Grimes,et al.  Design and application of a wireless, passive, resonant-circuit environmental monitoring sensor , 2001 .

[7]  E. Jafer,et al.  Wireless Measurement System for Capacitive pressure Sensors Using Strain Compensated SiGeB , 2007, 2007 IEEE Sensors.

[8]  Wen H. Ko,et al.  Touch mode capacitive pressure sensors , 1999 .

[9]  K.G. Ong.  Magnetically-soft higher-order harmonic stress and temperature sensors , 2003, Digest of INTERMAG 2003. International Magnetics Conference (Cat. No.03CH37401).

[10]  Keat G Ong,et al.  Tracking the harmonic response of magnetically-soft sensors for wireless temperature, stress, and corrosive monitoring. , 2002, Sensors and actuators. A, Physical.

[11]  R. Weigel,et al.  Optimized design and fabrication of a wireless pressure and temperature sensor unit based on SAW transponder technology , 2001, 2001 IEEE MTT-S International Microwave Sympsoium Digest (Cat. No.01CH37157).

[12]  W. Ko,et al.  Touch mode capacitive pressure sensors for industrial applications , 1997, Proceedings IEEE The Tenth Annual International Workshop on Micro Electro Mechanical Systems. An Investigation of Micro Structures, Sensors, Actuators, Machines and Robots.

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

[14]  M. Ju,et al.  A contact-type piezoresistive micro-shear stress sensor for above-knee prosthesis application , 2001 .

[15]  M. Allen,et al.  Micromachined endovascularly-implantable wireless aneurysm pressure sensors: from concept to clinic , 2005, The 13th International Conference on Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05..

[16]  A A Polliack,et al.  Laboratory and clinical tests of a prototype pressure sensor for clinical assessment of prosthetic socket fit , 2002, Prosthetics and orthotics international.

[17]  E. Jafer,et al.  A Wireless Sensor Network System for Pressure and Temperature Signals Monitoring , 2007, 2007 IEEE International Symposium on Industrial Electronics.

[18]  K. Wise,et al.  An ultraminiature solid-state pressure sensor for a cardiovascular catheter , 1988 .

[19]  O. Korostynska,et al.  Development of Wireless Pressure Measurement System for Short Range medical Applications , 2007, 2007 30th International Spring Seminar on Electronics Technology (ISSE).

[20]  K. Wise,et al.  A double-sided single-chip wireless pressure sensor , 2002, Technical Digest. MEMS 2002 IEEE International Conference. Fifteenth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.02CH37266).

[21]  R. Puers,et al.  Passive telemetry by harmonics detection , 1996, Proceedings of 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

[22]  Krassi Ivancev,et al.  Intra-aneurysm pressure measurements in successfully excluded abdominal aortic aneurysm after endovascular repair. , 2003, Journal of vascular surgery.

[23]  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).

[24]  Gerald Ostermayer.  Correlative signal processing in wireless SAW sensor applications to provide multiple-access capability , 2001 .

[25]  J. Muehlsteff,et al.  Wireless Body Sensor Network for Continuous Cuff-less Blood Pressure Monitoring , 2006, 2006 3rd IEEE/EMBS International Summer School on Medical Devices and Biosensors.

[26]  Craig A. Grimes,et al.  Control of a magnetoelastic sensor temperature response by magnetic field tuning , 2003 .

[27]  Li Zhang,et al.  A Self-Energized Sensor for Wireless Injection Mold Cavity Pressure Measurement: Design and Evaluation , 2004 .