Improvement of Sensitivity to In-plane Strain/Deformation Measurement by Micro-ESPI Technique

마이크로 ESPI 기법에 의한 면내 변형 측정 민감도 향상

  • 김동일 (전남대학교 기계공학과) ;
  • 기창두 (전남대학교 기계시스템공학부) ;
  • 허용학 (한국표준과학연구원 환경안전계측연구센터)
  • Published : 2006.08.01

Abstract

Enhancement methods of sensitivity to in-plane strain measurement by micro-ESPI(Electronic Speckle Pattern Interferometry) technique were proposed using TiN and Au thin films. Micro-tensile strain over the micro-tensile specimens, prepared in micro-scale by those films, was measured by micro-tensile loading system and micro-ESPI system developed in this study. The subsequent measurement of in-plane tensile strain in the micro-sized specimens was introduced using the micro-ESPI technique, and the micro-tensile stress-strain curves for these films were determined. To enhance the sensitivity to measurement of in-plane tensile strain, algorithms of the phase estimation by using curve fitting of inter-fringe and the discrete Fourier Transform with object-induced dynamic phase shifting were developed. Using these two algorithms, the micro-tensile strain-stress curves were generated. It is shown that the algorithms for enhancement of the sensitivity suggested in this study make the sensitivity to measurement of the in-plane tensile strain increase.

Keywords

References

  1. Sharpe W. N. Jr., Yuan, B. and Edwards, R. L., 'A New Technique for Measuring the Mechanical Properties of Thin Films,' J. microelectromechn. Syst., Vol. 6, No.3, pp. 193-199, 1997 https://doi.org/10.1109/84.623107
  2. Espinosa, H. D., Prorok, B. C. and Fisher, M., 'A Novel Experimental Technique for Testing Thin Films and MEMS Materials,' Proc. of the SEM Annual Conf., pp. 446-449, 2001
  3. Huh, Y. H., Kim, D. I., Kim, D. J., Park, P., Kee, C. D. and Park, J. H., 'Application of Micro-ESPI Technique for Measurement of Micro-Tensile Properties,' Key Eng. Materials, Vol. 270, pp. 744-749,2004 https://doi.org/10.4028/www.scientific.net/KEM.270-273.744
  4. Kim, D. I., Huh, Y. H. and Kee, C. D., 'Measurement of Tensile Properties of Copper Foil using Micro-ESPI Technique,' J. of KSPE, Vol. 21, No.8, pp. 89-96,2004
  5. Rastogi, P. K., 'Digital Speckle Pattern Interferometry and Related Techniques,' John Wiley & Sons, Ltd., 2001
  6. Madjarova, V., Satoru, T, Rini, W. and Hirofumi, K., 'Dynamic ESPI with Subtraction Addition Method for Obtaining the Phase, ' Optcom, Vol. 212, pp. 35-43,2002 https://doi.org/10.1016/S0030-4018(02)01909-0
  7. Xavier, C. D. L. and Pierre, J., 'Deformation Measurement with Object-Induced Dynamic Phase Shifting,' Optical Society of America, Vol. 35, No. 25, pp. 5115-5121, 1996 https://doi.org/10.1364/AO.35.005115
  8. Xavier, C. D. L. Pierre, J., 'Interferometric Deformation Measurement Using Object Induced Dynamic Phase-Shifting,' SPIE, Vol. 2782, pp. 169-179,1996 https://doi.org/10.1117/12.250742
  9. Surrel, Y., 'Phase Stepping; A New Self-Calibration Algorithm,' Applied Optics, Vol. 32, No. 19, pp. 3598 -3600, 1993 https://doi.org/10.1364/AO.32.003598
  10. Mohamed, G.E.H., 'The MEMS Handbook,' CRC Press, 2002