Thermal-Piezoresistive Resonators and Self-Sustained Oscillators for Gas Recognition and Pressure Sensing

This paper presents experimental and theoretical investigation of the response of microscale dual-plate thermal-piezoresistive resonators (TPRs) and self-sustained oscillators (TPOs) to different gases and pressures. It is demonstrated that the resonant frequency of such devices follow particular trends in response to the changes in the surrounding gas and its pressure. A mathematical model is derived to explain the damping dependent frequency shift characteristic of the TPO. The solution of the model indicates that the stiffness of the actuator beam decreases as the value of the damping coefficient drops at lower gas density caused by the change in the gas molecular mass or pressure. When operated in the TPR mode (linear operation), however, the frequency shift of the same silicon structure is mainly a function of gas thermal conductivity. The two different sensing mechanisms are confirmed by the measurement results showing opposite frequency shift for the TPR and TPO in helium-nitrogen mixtures. In pressure tests, frequency shifts as high as -2300 ppm are measured for a TPO by changing the air pressure from 84 to 43 kPa.

[1]  Kenneth E. Goodson,et al.  Investigation of the Natural Convection Boundary Condition in Microfabricated Structures , 2008 .

[2]  Claude Lucat,et al.  Dynamic thermal conductivity sensor for gas detection , 2004 .

[3]  A. Abdel-azim.  Fundamentals of Heat and Mass Transfer , 2011 .

[4]  Junbo Wang,et al.  A micromachined resonant pressure sensor with DETFs resonator and differential structure , 2009, 2009 IEEE Sensors.

[5]  Hidemoto Nakagawa,et al.  A fiber-optic evanescent-wave hydrogen gas sensor using palladium-supported tungsten oxide , 2000 .

[6]  Siavash Pourkamali,et al.  Fully micromechanical piezo-thermal oscillators , 2010, 2010 International Electron Devices Meeting.

[7]  Mohan Gupta.  Fundamentals of Heat and Mass Transfer , 2014 .

[8]  H. Seidel,et al.  Vacuum pressure and gas detection with a silicon based micromechanical squeeze film sensor , 2010 .

[9]  Yasushi Goto,et al.  A study of fast response characteristics for hydrogen sensing with platinum FET sensor , 2006 .

[10]  Michael Arndt,et al.  Thermal and gas-sensing properties of a micromachined thermal conductivity sensor for the detection of hydrogen in automotive applications , 2002 .

[11]  Christopher Niezrecki,et al.  Miniature all-silica optical fiber pressure sensor with an ultrathin uniform diaphragm. , 2010, Optics express.

[12]  T. Veijola,et al.  Compact damping models for laterally moving microstructures with gas-rarefaction effects , 2001 .

[13]  S. Pourkamali,et al.  Fabrication and Characterization of MEMS-Based Resonant Organic Gas Sensors , 2012, IEEE Sensors Journal.

[14]  E. Bakhoum,et al.  Capacitive Pressure Sensor With Very Large Dynamic Range , 2010, IEEE Transactions on Components and Packaging Technologies.

[15]  Li Xin,et al.  High-temperature piezoresistive pressure sensor based on implantation of oxygen into silicon wafer , 2012 .

[16]  M. K. Andrews,et al.  A resonant pressure sensor based on a squeezed film of gas , 1993 .

[17]  S. Pourkamali,et al.  Individual Air-Borne Particle Mass Measurement Using High-Frequency Micromechanical Resonators , 2011, IEEE Sensors Journal.

[18]  Charles S. Smith.  Piezoresistance Effect in Germanium and Silicon , 1954 .

[19]  S. Pourkamali,et al.  High-Frequency Thermally Actuated Electromechanical Resonators With Piezoresistive Readout , 2011, IEEE Transactions on Electron Devices.

[20]  Dieter Zeisel,et al.  A precise and robust quartz sensor based on tuning fork technology for (SF6)-gas density control , 2000 .

[21]  Weiwei Xing,et al.  Non-linear dynamics of an electrothermally excited resonant pressure sensor , 2012 .

[22]  Chun-Hyung Cho,et al.  Characterization of Young's modulus of silicon versus temperature using a ``beam deflection'' method with a four-point bending fixture , 2009 .

[23]  Tomi Mattila,et al.  Nonlinear mechanical effects in silicon longitudinal mode beam resonators , 2005 .

[24]  Zeng-Yuan Guo,et al.  Size effect on microscale single-phase flow and heat transfer , 2002 .