Xin Kang This email address is being protected from spambots. You need JavaScript enabled to view it.1,2, Ding-Guo Zhang1 and Ming Jiang3

1Department of Applied Mechanics, Nanjing University of Science and Technology, Nanjing 210094, P.R. China
2Department of Mechanical and Aeronautical Engineering, University of California, Davis, 95616, US
3Department of Engineering Mechanics, Suzhou University of Science and Technology, Suzhou 215011, P.R. China


 

Received: December 10, 2012
Accepted: June 28, 2013
Publication Date: December 1, 2013

Download Citation: ||https://doi.org/10.6180/jase.2013.16.4.03  


ABSTRACT


In this paper the dynamic characteristics of a piezoelectric micromachined ultrasonic transducer (pMUT) was studied using couple stress theory and Rayleigh-Ritz method. The transducer membrane is a multilayered disc, which includes a piezoelectric layer, an elastic layer and two electrode layers. Since the whole thickness of the transducer membrane is in micro-scale, the size dependence of the dynamic deformation behavior was evaluated using couple stress theory. The response of the transducer to ultrasonic wave was analyzed using modal decomposition and Bessel function, and was implemented by Matlab software. The results show that the non-dimensional rigidity of the transducer membrane increases obviously when the thickness of the membrane is in micro-scale, and this results in a shift of the resonant frequency of the transducer. Moreover the output electric charge and voltage for the first mode of the transducer are reduced accordingly because of the increase of non-dimensional rigidity. Further analysis shows that the optimal diameter ratio of top electrode to transducer membrane for a maximal output of electric charge obtained by the first mode is around 0.674. However this diameter ratio is not applicable to the output voltage for an open-circuit system.


Keywords: Piezoelectric Micromachined Ultrasonic Transducer, Dynamic Characteristics, Size Effect, Rayleigh-Ritz Method


REFERENCES


  1. [1] Shung, K. K., Cannata, J. M. and Zhou, Q. F., “Piezoelectric Materials for High Frequency Medical Imaging Applications: A Review,” Journal of Electroceramics, Vol. 19, No. 1, pp. 141147 (2007). doi: 10.1007/s10832-007-9044-3
  2. [2] Marechal, P., Levassort, F., Holc, J., Tran-Huu-Hue, L.-P., Kosec, M. and Lethiecq, M., “High-Frequency Transducers Based on Integrated Piezoelectric Thick Films for Medical Imaging,” IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 53, No. 8, pp. 15241533 (2006). doi: 10.1109/ TUFFC.2006.1665110
  3. [3] Wooh, S.-C. and Wang, J., “Nondestructive Characterization of Defects Using a Novel Hybrid Ultrasonic Array Sensor,” NDT & E International, Vol. 35, No. 3, pp. 155163 (2002). doi: 10.1016/S0963-8695(01) 00038-X
  4. [4] Park, J., Je, Y., Lee, H. and Moon, W., “Design of an Ultrasonic Sensor for Measuring Distance and Detecting Obstacles,” Ultrasonics, Vol. 50, No. 3, pp. 340–346 (2010). doi: 10.1016/j.ultras.2009.10.013
  5. [5] Shin, S. W., Qureshi, A. R., Lee, J.-Y. and Yun, C. B., “Piezoelectric Sensor Based Nondestructive Active Monitoring of Strength Gain in Concrete,” Smart Materials and Structures, Vol. 17, No. 5, pp. 055002 (2008). doi: 10.1088/0964-1726/17/5/055002
  6. [6] Mo, Y., Tanaka, T., Inoue, K., Yamashita, K. and Suzuki, Y., “Front-End Processor Using BBD Distributed Delay-Sum Architecture for Micromachined Ultrasonic Sensor Array,” Journal of Microelectromechanical Systems, Vol. 12, No. 4, pp. 506512 (2003). doi: 10.1109/JMEMS.2003.815840
  7. [7] Akasheh, F., Myers, T., Fraser, J. D., Bose, S. and Bandyopadhyay, A., “Development of Piezoelectric Micromachined Ultrasonic Transducers,” Sensor and Actuators A: Physical, Vol. 111, No. 2-3, pp. 275287 (2004). doi: 10.1016/j.sna.2003.11.022
  8. [8] Muralt, P., Ledermann, N., Baborowski, J., et al, “Piezoelectric Micromachined Ultrasonic Transducers Based on PZT Thin Film,” IEEE Transaction on Ultrasonics, Ferroelectrics, and Frequency Control, Vol. 52, No. 12, pp. 22762288 (2005). doi: 10.1109/ TUFFC.2005.1563270
  9. [9] Chong, A. C. M., Yang, F., Lam, D. C. C. and Tong, P., “Torsion and Bending of Micro-Scale Structures,” J. Mater. Res., Vol. 16, No. 4, pp. 10521058 (2001). doi: 10.1557/JMR.2001.0146
  10. [10] Fleck, N. A., Muller, G. M., Ashby, M. F., et al., “Strain Gradient Plasticity: Theory and Experiment,” Acta Metall Mater, Vol. 42, No. 2, pp. 475487 (1994). doi: 10.1016/0956-7151(94)90502-9
  11. [11] Stolken, J. S. and Evans, A. G., “A Microbend Test Method for Measuring the Plasticity Length Scale,” Acta Mater, Vol. 46, No. 14, pp. 51095115 (1998). doi: 10.1016/S1359-6454(98)00153-0
  12. [12] Yang, F., Chong, A. C. M., Lam, D. C. C. and Tong, P., “Couple Stress Based Strain Gradient Theory for Elasticity,” International Journal of Solids and Structures, Vol. 39, No. 10, pp. 27312743 (2002). doi: 10.1016/ S0020-7683(02)00152-X
  13. [13] Mindlin, R. D. and Tiersten, H. F., “Effect of CoupleStresses in Linear Elasticity,” Arch Rational Mech Anal, Vol. 11, No. 1, pp. 415448 (1962). doi: 10. 1007/BF00253946
  14. [14] Toupin, R. A., “Elastic Materials with Couple-Stresses,” Arch Rational Mech Anal, Vol. 11, No. 1, pp. 385414 (1962). doi: 10.1007/BF00253945
  15. [15] Ke, L. L., Wang, Y. S., Yang, J. and Kitipornchai. S., “Free Vibration of Size-Dependent Mindlin Microplates Based on the Modified Couple Stress Theory,” Journal of Sound and Vibration, Vol. 331, No. 1, pp. 94106 (2012). doi: 10.1016/j.jsv.2011.08.020
  16. [16] Roque, C. M. C., Fidalgo, D. S., Ferreira, A. J. M. and Reddy, J. N., “A Study of a Microstructure-Dependent Composite Laminated Timoshenko Beam Using a Modified Couple Stress Theory and a Meshless Method,” Composite Structures, Vol. 96, pp. 532537 (2013). doi: 10.1016/j.compstruct.2012.09.011
  17. [17] Ding, J. N., Meng, Y. G. and Wen, S. Z., “Research of the Size Effect on Strength of Polysilicon MicroElectro-Mechanical Devices,” Journal of Mechanical Strength, Vol. 23, No. 4, pp. 385388 (2001). (In Chinese)
  18. [18] Hwang, K., Qiu, X. M. and Jiang, H. Q., “Recent Advances in Strain Gradient Plasticity - I - Couple Stress Theory and SG Theory,” Journal of Mechanical Strength, Vol. 21, No. 2, pp. 8187 (1999). (In Chinese)
  19. [19] Chen, S. H. and Wang, Z. Q., “Advances in Strain Gradient Theory,” Advances in Mechanics, Vol. 33, No. 2, pp. 207216 (2003). (In Chinese)
  20. [20] Pradhan, K. K. and Chakraverty, S., “Free Vibration of Euler and Timoshenko Functionally Graded Beams by Rayleigh-Ritz Method,” Composites: Part B (2013). doi: 10.1016/j.compositesb.2013.02.027
  21. [21] Zhou, D., “Vibrations of Mindlin Rectangular Plates with Elastically Restrained Edges Using Static Timoshenko Beam Function with the Rayleigh-Ritz Method,” International Journal of Solids and Structures, Vol. 38, No. 3233, pp. 55655580 (2001). doi: 10. 1016/S0020-7683(00)00384-X
  22. [22] Ilanko, S., “Comments on the Historical Bases of the Rayleigh and Ritz Methods,” Journal of Sound and Vibration, Vol. 319, pp. 731733 (2009). doi: 10. 1016/j.jsv.2008.06.001
  23. [23] Grossi, R. O. and Albarracin. C. M., “Some Observation on the Application of the Rayleigh-Ritz Method,” Applied Acoustics, Vol. 62, No. 10, pp. 11711182 (2001). doi: 10.1016/S0003-682X(00)00097-9
  24. [24] Kang, X., Yang, F. J. and He, X. Y, “Nonlinearity Analysis of Piezoelectric Micro Machined Ultrasonic Transducers Based on Couple Stress Theory,” Acta Mechanica Sinica, Vol. 28, No. 1, pp. 104111 (2012). doi: 10.1007/s10409-012-0019-5