NDTnet - September 1996, Vol.1 No.09

POLYMER PIEZOELECTRIC TRANSDUCERS FOR ULTRASONIC NDE

Authors Yoseph Bar-Cohen, Tianji Xue and Shyh-Shiuh Lih

Transducer Workshop

Abstract


INTRODUCTION - PIEZOELECTRIC SENSORS AND ACTUATORS

PIEZOELECTRIC POLYMERS

ORIGIN OF PIEZOELECTRICITY IN PVDF

FIGURE 1: Schematic view of two of the PVDF phases. The alpha-phase consists of a series of
non-polar anti-parallel chains, whereas beta-phase phase consists of a series of polar parallel chains.

FIGURE 2: Relative transverse d constant as a function of angle with the drawing direction
[Fukada and Yasuda, 1964].

FIGURE 3: Temperature dependence of the piezoelectric coupling constant for PVDF in the
drawing direction (K31) and normal to the film plane (K33) [Ohigashi, 1976].

APPLICATION OF PIEZOELECTRIC POLYMERS FOR ULTRASONIC NDE

CONCLUDING REMARKS

ACKNOWLEDGEMENT

REFERENCES

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  3. Chen Q. X. and P. A. Payne, "Industrial Applications of Piezoelectric Polymer Transducers," Measurement Sciences and Technology, Vol. 6, (1995), pp. 249-267.
  4. Chen, W.H., et al, "PVF2 Transducers for NDE," 1978 Ultrasonics Symposium Proceedings, Institute of Electrical and Electronic Engineering, New York, NY, (1978), pp.780-783.
  5. Fukada, E., J. Yasuda, Jpn J. Appl. Phys. No. 3 (1964) p. 117
  6. Harsanji, G., Polymer films in Sensor Applications, Technomic Publishing Co., Lancaster, PA, (1995).
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  9. Lee, C. -K., "Theory of Laminated Piezoelectric Plates for the Design of Distributed Sensors/Actuators, Part I and II," J. Acoust. Soc. Am., Vol. 89, (1990) , pp. 1144-1158.
  10. Lee, C. -K., and F. C. Moon, "Modal Sensors/Actuators," Trans of the ASME, J. of Appl. Mech. Vol. 57, (1990), pp. 434-441.
  11. Lines, M. E., and A. M. Glass, Principles and Applications of Ferroelectric Related Materials, Clarendon Press, Oxford, (1977).
  12. Murayama, N., H. Nakanura, H. Obara and M. Segawa, " The Strong Piezoelectricity in Polyvinylidene Fluoride (PVDF)," Ultrasonics, Vol. 14, No. 1, (1976), pp. 15-23.
  13. Ohigashi H., J. Appl. Phy. Vol. 47, (1976), p. 949.
  14. Ohigashi, H. "Ultrasonic Transducers in the Megahertz Range," in The Applications of Ferroelectric Polymers, Ed., T. T. Wang, J. M. Herbert and A. M. Glass, Chapman and Hall, New York, (1988).
  15. Shaw, H. J., et al, "PVF2 Transducers," 1980 Ultrasonics Symposium Proceedings, Institute of Electrical and Electronic Engineering, New York, NY (1981), pp. 927-940.
  16. Smolorz, S.; Grill, W., "Focusing PVDF transducers for acoustic microscopy" Research in Nondestructive Evaluation, Springer-Verlag, New York, NY, USA, Vol. 7, No. 4, (1995), pp. 195-201.
  17. Stiffler, R. and E.G. Henneke II, "The Application of Polyvinylidene Fluoride as an Acoustic Emission Transducer for Fibrous Composite Materials," Materials Evaluation, Vol. 41, No. 8, (1983), pp. 956-960.
  18. Sussner, H., "The Piezoelectric Polymer PVF2 and its Applications," 1979 Ultrasonics Symposium Proceedings, (1979), pp. 491-498.
  19. Tamura, M., T. Yamguchi, T. Oyaba and T Yoshimi, "Electroacoustic Transducers with Piezoelectric High Polymer Films, " J. Audio Eng. Soc. , Vol. 23, No. 1, (1975), pp. 21-26.
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      Authors:

        foto Dr. Yoseph Bar-Cohen is a physicist with over 25 years experience in NDE, sensors and electroactive materials. He is a Technical Staff and the NDE/Advanced Actuators Principal Investigator at the Science and Technology Development Section of the Jet Propulsion Laboratory, Pasadena, CA.
        Dr. Bar-Cohen received his Ph. D. in Physics (1979) and M.Sc. in Materials Science (1973), both from the Hebrew University at Jerusalem in Israel.
        Dr. Bar-Cohen is the Editor of the NASA NDE Working Group (NNWG) Newsletter and in 95/96 he was the Chair of NNWG. He is an Adjunct Professor at the Department of the Mechanical and Aerospace Engineering, the University of California, Los Angeles (UCLA) and an Advisor for the NRC Research Associateship Program. He is also a Fellow of ASNT.
        E-mail: yosi@jpl.nasa.gov
        Home Page: NASA NDE Working Group

        Dr. Tianji Xue is a Postdoc at the Jet Propulsion Laboratory (JPL), Pasadena Ca. He joined the NDE & Advanced Actuators Team in June, 1996 after he completed the requirements of his Ph. D. degree. Xue received his BS degree in Optical Engineering from the Beijing Institute of Technology, and his MS and Ph.D. degrees in Electrical Engineering from Iowa State University.
        Xue has experience in ultrasonic wave propagation with application to nondestructive evaluation semiconductor and thin film devices design and characterization; optical system design, image formation and processing; and numerical modeling of electromagnetic. At JPL, Xue is working on NDE of Composites as well as the development of electroactive polymers for muscle actuators.

        Dr. Shyh-Shiuh Lih is a mechanical engineer and a Member of the Technical Staff at the Technical Staff at the Science and Technology Development Section, JPL. He joined the NDE and Advanced Actuators Team at JPL in 1995. He is active in research and development of piezoelectric actuators and nondestructive evaluations (NDE) techniques for space applications.
        Dr. Lih has been a Research Engineer at the Mechanical, Aerospace and Nuclear Engineering Department, UCLA from 1992-1994. His technical expertise are dynamic response of piezoelectric actuators, composite materials and structures, NDE of materials, adhesive joints and thin films, mechanics of advanced materials, finite element analysis, and modeling and analysis of aerospace structures and components.
        Dr. Lih has been a consultant at JPL from 1993 to 1995, where he developed and performed a series of ultrasonic experiments to characterize the elastic properties of composite materials, adhesive joints, and damping of materials and demonstrated that the calculated wave forms based on the suggested models are in remarkable agreement with laboratory data.


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