A novel high sensitive capacitive pressure sensor for measuring intraocular pressure

  • Authors

    • Sajjad Mardaneh Faculty of Engineering 2, Islamic Azad University, Tabriz Branch, Tabriz, Iran
    • Maryam Taghi Dokht Ahrabi Faculty of Engineering 2, Islamic Azad University, Tabriz Branch, Tabriz, Iran
    • Seyyed Yousef Shafiei Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran
    2019-06-12
    https://doi.org/10.14419/ijet.v7i4.19532
  • Capacitive Pressure Sensor, COMSOL Multiphysics, Deflection, Displacement, Intraocular Pressure Sensor, MEMS.

  • In this paper, a new MEMS-based capacitive pressure sensor have been designed and characterized to measure pressures in the range of 0 - 60 mmHg (i.e. 0-8 KPa) that is in the range of intraocular pressure sensors. Intraocular pressure sensors are important in the early detection and treatment of Glaucoma which is an incurable disease. Two sensor designs incorporating conventional and slotted diaphragm are implemented and compared to realize the pressure-sensitive components. The novelty of this method relies on diaphragm includes some slots to reduce the effect of residual stress and stiffness of diaphragm and increase sensor sensitivity. The slotted diaphragm makes ca-pacitive pressure sensor more sensitive, that is more suitable for measuring intraocular pressure sensor. The results yield a sensitivity of 1.113×10-4 1/Pa for the conventional and 2.375×10-4 1/Pa for the slotted pressure sensor with a 0.5 × 0.5 mm2 diaphragm. It can be seen that the sensitivity of the sensor with slotted diaphragm increased 2.13 times compared with the conventional diaphragm. Furthermore, the resonance frequency for the conventional diaphragm is 143.29 KHz while the resonance frequency for the slotted diaphragm is 128.75 KHz.

     

     

  • References

    1. [1] D. Ha, W. N. de Vries, S. W. John, P. P. Irazoqui, and W. J. Chappell, "Polymer-based miniature flexible capacitive pressure sensor for intraocular pressure (IOP) monitoring inside a mouse eye," Biomedical microdevices, vol. 14, pp. 207-215, 2012. https://doi.org/10.1007/s10544-011-9598-3.

      [2] S. Zargari, S. Falaki, and H. Veladi, "Design and finite element analysis of a MEMS based capacitive pressure sensor using CNT/PDMS nanocomposite electrodes," in Electrical Engineering (ICEE), 2016 24th Iranian Conference on, 2016, pp. 1619-1623. https://doi.org/10.1109/IranianCEE.2016.7585780.

      [3] D. G. Khushalani, V. R. Dubey, P. P. Bheley, J. P. Kalambe, R. S. Pande, and R. M. Patrikar, "Design optimization & fabrication of micro cantilever for switching application," Sensors and Actuators A: Physical, vol. 225, pp. 1-7, 2015. https://doi.org/10.1016/j.sna.2014.10.038.

      [4] S.-P. Chang and M. G. Allen, "Capacitive pressure sensors with stainless steel diaphragm and substrate," Journal of Micromechanics and Microengineering, vol. 14, p. 612, 2004. https://doi.org/10.1088/0960-1317/14/4/023.

      [5] S.-P. Chang and M. G. Allen, "Demonstration for integrating capacitive pressure sensors with read-out circuitry on stainless steel substrate," Sensors and Actuators A: Physical, vol. 116, pp. 195-204, 2004. https://doi.org/10.1016/j.sna.2004.04.010.

      [6] S. T. Cho, K. Najafi, and K. D. Wise, "Internal stress compensation and scaling in ultrasensitive silicon pressure sensors," IEEE Transactions on Electron Devices, vol. 39, pp. 836-842, 1992. https://doi.org/10.1109/16.127473.

      [7] M. Shahiri-Tabarestani, B. Ganji, and R. Sabbaghi-Nadooshan, "Design and simulation of high sensitive capacitive pressure sensor with slotted diaphragm," in Biomedical Engineering (ICoBE), 2012 International Conference on, 2012, pp. 484-489. https://doi.org/10.1109/ICoBE.2012.6179064.

      [8] C. Muhlstein, E. Stach, and R. Ritchie, "A reaction-layer mechanism for the delayed failure of micron-scale polycrystalline silicon structural films subjected to high-cycle fatigue loading," Acta Materialia, vol. 50, pp. 3579-3595, 2002. https://doi.org/10.1016/S1359-6454(02)00158-1.

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  • How to Cite

    Mardaneh, S., Taghi Dokht Ahrabi, M., & Yousef Shafiei, S. (2019). A novel high sensitive capacitive pressure sensor for measuring intraocular pressure. International Journal of Engineering & Technology, 7(4), 6306-6308. https://doi.org/10.14419/ijet.v7i4.19532