A MEMS tilt sensor with expanded operating range and improved sensitivity

In this paper, a simple and novel method of expanding the operating range of inclinations and of increasing the sensitivity of convection-based tilt sensors is shown. Even though the previously reported convective tilt sensors fabricated in our laboratory have their own merits in performing dual-axes inclination measurement with excellent linearity and symmetric sensitivity, they showed limited operating range from −90 to 90° because of their structural limitations. However, this proposed tilt sensor has overcome the structural limitations and it detects inclinations wider than the ±90° range on two axes with symmetric sensitivity. The improved performance could be achieved by removing the membrane at the bottom of the microheater and temperature sensors for unlimited gas movement in the cavity when it tilted over the ±90° range. The operating range of the newly proposed tilt sensor expands to ±180° compared with that of the previously reported convective tilt sensor. Moreover, various designs of cavities and cap substrates were adopted to improve the sensitivity of the proposed convective tilt sensor. The mass production of the proposed convection-based tilt sensor is still feasible because it can be fabricated at a low cost because of its simple fabrication step. Its sensitivity is high and it has a very wide-angle detection range.

[1]  R B Stein,et al.  Application of tilt sensors in functional electrical stimulation. , 1996, IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society.

[2]  Zhixin Li,et al.  An optimized micromachined convective accelerometer with no proof mass , 2001 .

[3]  Yu-Luen Chen,et al.  Application of tilt sensors in human-computer mouse interface for people with disabilities. , 2001, IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society.

[4]  J. Frech,et al.  Convection-based micromachined inclinometer using SOI technology , 2001, Technical Digest. MEMS 2001. 14th IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.01CH37090).

[5]  Y. J. Yang,et al.  Thermal optimization on micromachined convective accelerometer , 2002 .

[6]  Walter Lang,et al.  Micromachined inclinometer with high sensitivity and very good stability , 2002 .

[7]  Frédérick Mailly,et al.  Effect of gas pressure on the sensitivity of a micromachined thermal accelerometer , 2003 .

[8]  Y. J. Yang,et al.  Study on linearity of a micromachined convective accelerometer , 2003 .

[9]  D.M. Wilson,et al.  On a micromachined fluidic inclinometer , 2003, TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664).

[10]  P. Temple-Boyer,et al.  Micromachined thermal accelerometer , 2003 .

[11]  Baojin Peng,et al.  Experimental research on a novel fiber-optic cantilever-type inclinometer , 2005 .

[12]  Zhaoying Zhou,et al.  Micromachined gas inertial sensor based on convection heat transfer , 2006 .

[13]  Jih-Huah Wu,et al.  A two-axis tilt sensor based on optics , 2006 .

[14]  Jang-Kyoo Shin,et al.  Design and Fabrication of a Micro Electro Mechanical Systems-Based Electrolytic Tilt Sensor , 2006 .

[15]  Chang Jin Kim,et al.  An optimized MEMS-based electrolytic tilt sensor , 2007 .

[16]  Che-Hsin Lin,et al.  Micro-impedance inclinometer with wide-angle measuring capability and no damping effect ☆ , 2008 .

[17]  Yoshinori Matsumoto,et al.  Characterization of miniaturized one-side-electrode-type fluid-based inclinometer , 2008 .

[18]  G. Cathébras,et al.  Thermal simulation and experimental results of a micromachined thermal inclinometer , 2008 .

[19]  Alexander Peine,et al.  Technological paradigms and complex technical systems—The case of Smart Homes , 2008 .

[20]  Karen Willcox,et al.  Kinetics and kinematics for translational motions in microgravity during parabolic flight. , 2009, Aviation, space, and environmental medicine.

[21]  M. Chan,et al.  Smart homes - current features and future perspectives. , 2009, Maturitas.

[22]  Takahiro Matsuo,et al.  Development of Highly Integrated Quartz Micro-Electro-Mechanical System Tilt Sensor , 2009 .

[23]  Lijun Tang,et al.  MEMS inclinometer based on a novel piezoresistor structure , 2009, Microelectron. J..

[24]  Yusaku Fujii,et al.  Smart Car with Security Camera for Road Accidence Monitoring , 2011 .

[25]  D. Z. Stupar,et al.  A simple fibre optic inclination sensor based on the refraction of light , 2012 .