Dr. Zensheu Chang

Biography
Dr. Zensheu Chang is a Senior Member of the Technical Staff in the Advanced Technologies Group of the Jet Propulsion Laboratory. He joined JPL in March 1998. In 1997, Dr. Chang received his Ph.D. degree in Solid Mechanics from the Mechanical and Aerospace Engineering department, UCLA, and Master of Science degree in 1988 from the Mechanical Engineering department, National Taiwan University, Taipei, Taiwan. His research areas include structural dynamics, ultrasonic NDE/NDT, piezoelectric actuators, CAD/FEM modeling, elastic wave propagation, and solid mechanics. He has been involved in the development of the piezoelectric pump, and a variety of drilling, coring, and sampling tools including the Ultrasonic Sonic Driller Corer (USDC), the Ultrasonic Rock abrasion tool, rock crusher, Ultrasonic Gopher, Percussive-Rotary drill, and ultrasonic-rotary drill, etc. In addition to the research activities, Dr. Chang has also been involved in various NASA flight missions including MSL, SIM, WFIRST, etc. He was involved in the structural analysis of the RTG Heat Exchanger and the SA-SPaH of MSL. He was also a member of the tiger team that successfully resolved the high-stress issue with the Propulsion Lines of MSL’s Descend Stage. He has coauthored more than 80 papers, 4 patents, 17 NASA Tech Briefs, and 18 New Technology Reports in related research areas.

This homepage is maintained by the JPL's NDEAA Technologies Group

Zensheu Chang - List of Publications, NTRs, Awards and Registered Patents

New Technology Reports

1. V. Bach, P. Walkemeyer, M. Thomson, S. Brown, W. Imbriale, and Z. Chang, “Tangential Wrap Rib Deployable Reflector (TWR),” NTR Docket No. 49671, submitted on September 11, 2014.

2. X. Bao, M. Badescu, S. Sherrit, Y. Bar-Cohen, K. Kerenyi, S.-S. Lih, Z. Chang, S. Widholm, P. Ostlund, and B. P. Trease, “Sensor for boundary shear stress in fluid flow,” NTR Docket No. 47812, submitted on September 13, 2010. Provisional Patent filed on Dec. 13, 2010. NASA Tech Briefs, Vol. 36, No. 4, 2012, pp. 7-8

3. E. E. Bloemhof, J. C. Lam, V. A. Feria, and Z. Chang, “Extracting the zero-gravity surface figure of a mirror in a flightlike hexapod mount”, NTR Docket No. 47259, submitted on August 12, 2009. NASA Tech Briefs, Vol. 35, No. 1, 2011, pp. 34

4. Z. Chang, M Rhonda, E.-H. Yang, Y. Hishinuma, J. Su, and T.-B. Xu, “Active membrane using electrostructure graft elastomer for deployable and lightweight mirrors,” NTR Docket No. 45616, submitted on October 3, 2007. NASA Tech Briefs, Vol. 32, No. 11, 2008, pp. 54

5. S. Sherrit, B. Doty, X. Bao, Y. Bar-Cohen, M. Badescu, and Z. Chang, “Highly efficient wireless transmission of high power and signals through solid walls using Acoustic-Electric feed-through mechanism,” NTR Docket No. 44928, submitted on February 13, 2007. A provisional patent was submitted on April 23, 2007. NASA Tech Briefs, Vol. 32, No. 9, 2008, pp. 81

6. S. Sherrit, Y. Bar-Cohen, M. Badescu, X. Bao, Z Chang, C. Jones, J. Aldrich, “Compact Non-Pneumatic Powder Sampler (NPPS),” NTR Docket No. 43614, submitted on February 23, 2006. Tech Briefs, Vol. 32, No. 7, 2008, pp. 56-57

7. J. Aldrich, S. Sherrit, M. Badescu Y. Bar-Cohen, X. Bao, and Z. Chang, “Controller using extremum-seeking to drive heavily perturbed electroactive actuators at resonance” NTR Docket No. 43519, submitted on February 9, 2006. NASA Tech Briefs, Vol. 32, No. 4, 2008, pp. 40, 42

8. S. Sherrit, M. Badescu, Y. Bar-Cohen, Z. Chang, X. Bao, “Portable Rapid and Quiet Drill (PRAQD),” NTR Docket No. 42131, submitted on April 8, 2005. Patent disclosure submitted on Feb. 2006. NASA Tech Briefs, Vol. 31, No. 10, 2007, pp. 36, 38

9. X. Bao, Y. Bar-Cohen, Z. Chang, S. Sherrit and R. Stark, “Ultrasonic/Sonic Impacting Penetrator (USIP),” NTR Docket No. 41666, submitted on December 22, 2004. NASA Tech Briefs, Vol. 32, No. 4, 2008, pp. 58, 60.

10. S. Sherrit, Y. Bar-Cohen, Z. Chang and X. Bao, “Dog Bone Piezoelectric Actuation Horns,” NTR Docket No. 40949, submitted on February 25, 2004. NASA Tech Briefs, Vol. 31, No. 12, 2007, pp. 48, 50.

11. S. Sherrit, Y. Bar-Cohen, X. Bao, Z. Chang, D. Blake and C. Bryson, “Ultrasonic/Sonic Rock Powdering Sampler and Delivery Tool,” NTR Docket No. 40564, submitted on August 13, 2003, NASA Tech Briefs, Vol. 28, No. 1, 2004, pp. 51.

12. I. C. Paustian, Y. Bar-Cohen, J. L. Lopes, S. Sherrit, Z. Chang, D. L. Folds and X. Bao, “Sonar Lenses with Controllable Directivity using ERF (SLCoDE),” NTR submitted on November 13, 2002, Docket No. 30884 , NASA Tech Briefs, Vol. 28, No. 1, 2004, p. 54-55

13. S. Sherrit, X. Bao, Y. Bar-Cohen, B. Dolgin, and Z. Chang, “Ultrasonic Crusher for Crushing, Milling, and Powdering,” NTR submitted on June 21, 2002, Docket No. 30682, NASA Tech Briefs, Vol. 28, No. 8, 2004, pp. 48-49.

14. Y. Bar-Cohen, Z. Chang, M. Salama, X. Bao, S. Sherrit, C.H.M Jenkins and A. Vinogradov, “Controlled gossamer structures deployment and stability using ERF,” NTR submitted on March 12, 2002, Docket No. No. 30587, NASA Tech Briefs, Vol. 27, No. 2, 2003, p. 56

15. S. Sherrit, S. A. Askins, M. Gradziel, B. P. Dolgin, Y. Bar-Cohen, X. Bao, and Z. Chang, “Novel Ultrasonic Horns for power ultrasonics,” NTR, submitted on December 6, 2001, Docket No. 30489. NASA Tech Briefs, Vol. 27, No. 4, 2003, pp. 54-55.

16. Y. Bar-Cohen, Z. Chang, X. Bao, and S.-S. Lih “Piezopump – A Miniature Ring-Shape Peristaltic Pump,” NTR, submitted on October 26, 2001, Docket No. 30415. Provisional patent CIT-3588, submitted on 1/18/02. NASA Tech Briefs, Vol. 28, No. 2, 2004, pp. 50-51.

17. B. Dolgin, S. Sherrit, Y. Bar-Cohen, R. Rainen, S. Askins, D. Lewis, J. Carson, S. Dawson, X. Bao, Z. Chang, T. Peterson, and D. Bickler, “Ultrasonic Rock Abrasion Tool (URAT),” NTR submitted on Oct. 12, 2001, Docket No. 30403. NASA Tech Briefs, Vol. 30, No. 7, 2006, pp. 58

18. B. Dolgin, S. Sherrit, Y. Bar-Cohen, S. Askins, D. Sigel, X. Bao, and Z. Chang, “Ultrasonic/ Sonic Vibrating/Rotating Tool” NTR, submitted on Sept. 5, 2001, Docket No. 30370. NASA Tech Briefs, Vol. 26, No. 9, 2002, pp. 65

19. B. Dolgin, S. Sherrit, Y. Bar-Cohen and Z Chang, “Acoustic Binocular,” NTR, Docket No. 21227, Item No. 0808b, February 1, 2001.

AWARDS

1. Failure Analysis Associate Fellowship, September 1993.

2. NASA JPL NOVA Award (for Piezo-Pump), May 2001.

3. NASA JPL SPOT Award (for SAGE), October 2003.

4. NASA Team Bonus Award (for Quiet Concrete Drill), July 2005.

5. NASA Team Bonus Award (for MSL Prop Line Tiger Team), September 2008.

6. NASA Team Bonus Award (for SIM G2T), June 2009.

7. NASA Honors Award (for SIM Guide-2-Telescope Testbed Test), June 2009.

8. NASA Honors Award (for SIM-Lite Precision Positioning Mechanisms), July 2011.

9. NASA Honors Award (for SIM-Lite Astrometric Beam Combiner (ABC)), July 2011.

10. NASA Honors Award (for MSL Mechanical Team), July 2013.

11. NASA Team Bonus Award (for support of SWOT Mission Preliminary Design Review), September 2016.

12. NASA Team Bonus Award (for development of Smart Wire), September 2016.

13. NASA Team Bonus Award (for support of SWOT Mission Critical Design Review), September 2017.

14. NASA Honor Award (for support of the InSight project), August 2019.

15. NASA Team Bonus Award (for development of the CGI active elements for PDR), May 2020.

16. NASA Team Bonus Award (for support of the EMIT Telescope team for CDR), September 2020.

17. NASA Team Bonus Award (for contributions to CGI Precision Alignment Mechanism (PAM) team for the successful CGI CDR), August 2021.

18. NASA Team Bonus Award (for successful completion of the Lunar Trailblazer HVM3 hi-res imaging spectrometer PDR, and CDR for a new class of imaging spectrometer), September 2021.

19. NASA Team Bonus Award (for support of the NEO-S Telescope team for PDR), September 2022.

20. NASA Team Bonus Award (for outstanding technical contributions to the successful delivery of the Mechanical Flight Hardware for the HVM-3 Payload on Lunar Trailblazer), September 2022.

PATENTS

1. Folded horn for vibration actuators, Stewart Sherrit, Stephen Askins, Michael Gradziel, Benjamin Dolgin, Yoseph Bar-Cohen, Xiaoqi Bao, Zensheu Chang, and Thomas Peterson. (2004/0047,485)

2. Patent No. US 7,902,943 B2, Wireless acoustic-electric feed-through for power and signal transmission, Stewart Sherrit, Yoseph Bar-Cohen, Xiaoqi Bao, Benjamin Doty, Mircea Badescu, and Zensheu Chang. (2008/0258,841). Issued March 8, 2011.

3. Patent No. US 7,824,247 B1, Portable Rapid and Quiet Drill, Yoseph Bar-Cohen, Mircea Badescu, Xiaoqi Bao, Zensheu Chang, Stewart Sherrit. JPL Case No. P-42131, NASA Case No. NPO-42131-1-CU. Issued November 4, 2010.

4. Sensor for boundary shear stress in fluid flow, Xiaoqi Bao, Mircea Badescu, Stewart Sherrit, Yoseph Bar-Cohen, Shyh-Shiuh Lih, Zensheu Chang, Brian Trease, Kornel Kerenyi, Scott Widholm, and Patrick Ostlund. CIT File No. CIT-5752-P. Filed December 13, 2010.

Journal Papers

1. C.-C. Ma, Z. Chang and C.-H. Tsai, "Weight Functions of Oblique Edge and Center Cracks in Finite Bodies", Engineering Fracture Mechanics, Vol. 36, p.p. 267-285, 1990.

2. Z. Chang and A. Mal, "Scattering of Lamb Waves from a Rivet Hole with Edge Cracks", Mechanics of Materials, Vol. 31, p.p. 197-204, 1999.

3. A. Mal and Z. Chang, "A Semi-numerical Method for Elastic Wave Scattering Calculations", Geophysical Journal International, Vol. 143, p.p. 328-334, 2000.

4. X. Bao, Y. Bar-Cohen, Z. Chang, B. P. Dolgin, S. Sherrit, D. S. Pal, S. Du, and T. Peterson, "Modeling and Computer Simulation of Ultrasonic/Sonic Driller/Corer (USDC)" IEEE Transaction on Ultrasonics, Ferroelectrics, and Frequency Control (UFFC), Vol. 50(9), p.p. 1147-1160, 2003.

5. B. Kennedy, A. Okon, H. Aghazarian, M. Badescu, X. Bao, Y. Bar-Cohen, Z. Chang, B. E. Dabiri, M. Garrett, L. Magnone, and S. Sherrit; “Lemur IIb: a robotic system for steep terrain access”, Industrial Robot: An International Journal, Vol. 33(4), p.p. 265-269, 2006.

6. Y. Liu, C. Mavroidis, Y. Bar-Cohen, and Z. Chang, "Analytical and Experimental Study of Determining the Optimal Number of Wedge Shape Cutting Teeth in Coring Bits Used in Percussive Drilling", Journal of Manufacturing Science and Engineering, Transactions of the ASME, Vol. 129(4), p.p. 760-769, 2007.

7. E. H. Yang, Y. Hishinuma, J. Su, T.-B. Xu, R. Morgan, and Z. Chang, “Fabrication and Actuation of Silicon-EAP Bi-Layer Membranes for Active Lightweight Mirrors,” IOP Smart Materials and Structures, 2007. Submitted

8. K. Shcheglov, X. Jiang, R. Toda, Z. Chang, and E. H. Yang, “Hybrid linear microactuators and their control models for mirror shape correction,” Journal of Micro-Nano Mechatronics, Vol. 4, p.p. 159-167, 2009.

9. E. E. Bloemhof, J. C. Lam, V. A. Feria, and Z. Chang, "Precise determination of the zero-gravity surface figure of a mirror without gravity-sag modeling," Appl. Opt., Vol. 46(31), p.p. 7670-7678, 2007.

10. E. E. Bloemhof, J. C. Lam, V. A. Feria, and Z. Chang, "Extracting the Zero-Gravity Surface Figure of a Mirror through Multiple Clockings in a Flight-like Hexapod Mount," Appl. Opt., Vol. 48(21), p.p. 4239-4245, 2009.

Conference Papers

1. Z. Chang and A. K. Mal, "A Global-Local Method for Wave Propagation Across a Lap Joint", Numerical Methods in Structural Mechanics, J. W. Ju, ed., AMD-Vol. 204, p.p. 1-11, 1995.

2. Z. Chang, D. Guo and A. K. Mal, "Lamb Wave Propagation Across a Lap Joint", Review of Progress in QNDE, Vol. 15, p.p. 185-192, 1996.

3. A. Mal, Z. Chang, D. Guo and M. Gorman, "Lap Joint Inspection Using Plate Waves", NDE of Aging Aircraft, Airport, and Aerospace Hardware, SPIE Proceedings Vol. 2945, pp. 128-137, 1996.

4. Mal, A.K., Chang, Z., and Gorman, M., "Interaction of Lamb Waves with Defects in a Semi-infinite Plate," Rev. Progr. in QNDE, Vol. 16, pp. 397-404, 1996.

5. A. Mal, Z. Chang, and M. Gorman, "Interaction of Lamb Waves with Defects in a Semi-infinite Plate", Review of Progress in QNDE, Vol. 16, p.p. 153-160, 1997.

6. Z. Chang, "Wave Propagation in a Plate with Defects", Ph.D. Dissertation, 1997.

7. Y. Bar-Cohen, S.-S. Lih, A. Mal, and Z. Chang, "Rapid Characterization of the Degradation of Composites Using Plate Waves Dispersion Data", Review of Progress in QNDE, Vol. 17, p.p. 1171-1176, 1998.

8. Z. Chang and A. Mal, "Wave Propagation in a Plate with Defects", Review of progress in QNDE, Vol. 17, pp. 121-128, 1998.

9. Y. Bar-Cohen, A. Mal, and Z. Chang, "Defects Detection and Characterization Using Leaky Lamb Wave (LLW) Dispersion Data", ASNT ’98 Spring Conference, Joint with 9th Asia-Pacific Conference on NDT, and 7th Annual Research Symposium, Anaheim, CA, March 24-26, 1998, p.p. 195-197.

10. Mal, A.K. and Chang, Z.,"NDE of Rivet Holes in Aging Aircraft Components Using Leaky Lamb Waves", Non-Destructive Evaluation of Aging Aircraft, Airports and Aerospace Hardware, SPIE Proceedings Vol. 3397, pp. 68-75, 1998, Invited paper.

11. Y. Bar-Cohen, A. Mal, and Z. Chang, "Material Properties and Defects Characterization Using LLW Data", SPIE’s NDE Techniques for Aging Infrastructure & Manufacturing, Conference NDE of Materials and Composites II, SPIE Proceedings Vol. 3396, pp. 180-186, 1998.

12. Y. Bar-Cohen, A. Mal, and Z. Chang, "Characterization of Defects in Composite Material Using Rapidly Acquired Leaky Lamb Wave Dispersion Data", Proceedings of the 7th European Conference on Non-Destructive Testing, Vol. 1, p.p. 102-109, 1998.

13. Y. Bar-Cohen, S.-S., Lih and Z. Chang, "NDE Methods for Detection and Characterization of Aging Aircraft Related Defects in Metallic and Composite Materials", JPL report No. D-15991, AFOSR Contract F49620-95-1-0518, August 31, 1998, pp. 1-41.

14. Y. Bar-Cohen, A. K. Mal, S.-S. Lih and Z. Chang "Composite materials stiffness determination and defects characterization using enhanced leaky Lamb wave dispersion data acquisition method," Proceedings of the SPIE's 6th Annual International Symposium on NDE of Aging Aircraft, Airports, and Aerospace Hardware III, Newport Beach, CA, 3-5 March 1999, SPIE Proceedings Vol. 3586, pp. 250-255, Invited paper.

15. Y. Bar-Cohen, S.-S. Lih and Z. Chang "Progress and Challenges to NDE of Composites Using Obliquely Insonified Ultrasonic Waves," Submitted to the IMECE'99 - International Mechanical Engineering, ASME, Topic: Recent Advances of Ultrasonic NDE, Nashville, TN, Nov. 14-19, 1999.

16. Y. Bar-Cohen and Z. Chang, "Piezoelectrically Actuated Miniature Peristaltic Pump," ibid, SPIE Proceedings Vol. 3992, pp. 669-676, 2000.

17. S. Sherrit, X. Bao, Z. Chang, B.P. Dolgin, Y. Bar-Cohen, D. Pal, J. Kroh, and T. Peterson, "Modeling of the Ultrasonic/Sonic Driller/Corer: USDC", Proceedings of the IEEE Ultrasonics Symposium in San Juan, Puerto Rico, p.p. 691-694, Oct 22-25, 2000.

18. Y. Bar-Cohen, S. Sherrit, B. P. Dolgin, N. Bridges, X. Bao, Z. Chang, R. S. Saunders, D. Pal, J. Kroh, and T. Peterson, "Ultrasonic/Sonic Driller/Corer (USDC) as a Sampler for Planetary Exploration", Proceedings of the 2001 IEEE Aerospace Conference on the topic of Missions, Systems, and Instruments for In Situ Sensing (Session 2.05), Big Sky, Montana, March 10-17, 2001.

19. Y. Bar-Cohen and Z. Chang, "Piezoelectrically Actuated Miniature Peristaltic Pump", Proceedings of the Smart Structures and Integrated Systems, SPIE Proceedings Vol. 4327, pp. 425-432, 2001.

20. Y. Bar-Cohen, S. Sherrit, B. P. Dolgin, X. Bao, Z. Chang, D. S. Pal, and T. Peterson, "Ultrasonic/Sonic Drilling/Coring (USDC) For Planetary Applications", SPIE Proceedings Vol. 4327, pp. 441-448, 2001.

21. S. Sherrit, Y. Bar-Cohen, B. P. Dolgin, N. Bridges, X. Bao, Z. Chang, A. Yen, R. S. Saunders, R. A. Rainen, and S. F. Dawson, "Sample Acquisition and In-Situ Analysis Using the Ultrasonic/Sonic Driller/Corer (USDC) and Robotic Platforms", The 6th International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS-01), Montreal, Canada, June 18-21, 2001.

22. Z. Chang, B. Dolgin, X. Bao, S. Sherrit, and Y. Bar-Cohen, "Modeling of Particle Flow due to Ultrasonic Drilling", SPIE Proceedings Vol. 4701, pp. 361-367, 2002.

23. X. Bao, Z. Chang, S. Sherrit, B. P. Dolgin, Y. Bar-Cohen, D. S. Pal, S. Du, and T. Peterson, "Analysis and Simulation of the Ultrasonic/Sonic Driller/Corer (USDC)", SPIE Proceedings Vol. 4701, pp. 368-379, 2002.

24. S. Sherrit, S. A. Askins, M. Gradziol, B. P. Dolgin, X. Bao, Z. Chang, and Y. Bar-Cohen, "Novel Horn Designs for Ultrasonic/Sonic Cleaning, Welding, Soldering, Cutting, and Drilling", SPIE Proceedings Vol. 4701, pp. 353-360, 2002.

25. S. Sherrit, V. Olazabal, J. M. Sansinena, X. Bao, Z. Chang, and Y. Bar-Cohen, "The Use of Piezoelectric Resonators for the Characterization of Mechanical Properties of Polymers", SPIE Proceedings Vol. 4695, pp. 262-276, 2002.

26. Y. Bar-Cohen, X. Bao, Z. Chang and S. Sherrit, "Enabling novel space and terrestrial applications using transducing materials," Proceedings of the 2nd NASA Advanced Materials Symposium: New Directions in Advanced Materials Systems, Cleveland, Ohio May 29-31, 2002.

27. Y. Bar-Cohen, X. Bao, Z. Chang, and S. Sherrit, "Enabling novel space and terrestrial applications using transducing materials at JPL," Proceedings of the 2002 Photonics Fabrication Europe Symposium, Transducing Materials and Devices, Brugge, Belgium, Oct. 29-Nov. 1, 2002.

28. S. Sherrit, X. Bao, Y. Bar-Cohen, and Z. Chang, "BAW and SAW sensors for In-situ analysis," Proceedings of the SPIE Smart Structures Conference, SPIE Paper #5050-11, San Diego, CA., Mar 2-6, 2003.

29. X. Bao, Y. Bar-Cohen, Z. Chang and S. Sherrit, "Numerical modeling of electroactive polymer mirrors for space applications," Proceedings of the SPIE Smart Structures and Materials Symposium, EAPAD Conference, Paper #5051-45, San Diego, CA, March 3-6, 2003.

30. Y. Bar-Cohen, X. Bao, Z. Chang and S. Sherrit, "An Ultrasonic Sampler and Sensor Platform for In-situ Astrobiological Exploration," Proceedings of the SPIE Smart Structures and Materials Symposium, Paper #5056-55, San Diego, CA, March 3-6, 2003.

31. Z. Chang, S. Sherrit, X. Bao, and Y. Bar-Cohen, "In-situ Rock Probing Using The Ultrasonic/Sonic Driller/Corer (USDC)," Proceedings of the SPIE Smart Structures and Materials Symposium, Paper #5056-73, San Diego, CA, March 3-6, 2003.

32. Y. Bar-Cohen, S. Sherrit, X. Bao, and Z. Chang "Ultrasonic/Sonic Sampler and Sensor Platform for In-situ Planetary Exploration," Proceedings of the International Conference on MEMS, NANO, and Smart Systems held in Banff, Alberta - Canada, July 20 - July 23, 2003.

33. Y. Bar-Cohen, S. Sherrit, X. Bao and Z. Chang, "Real-time Sensing while Drilling using the USDC and Integrated Sensors," Invited Plenary presentation, Proceedings of the Eurosensors XVII Conference, Guimaraes, Portugal, September 21-24, 2003.

34. Z. Chang, S. Sherrit, X. Bao, and Y. Bar-Cohen "Design and analysis of ultrasonic horn for USDC (Ultrasonic/Sonic Driller/Corer), SPIE Smart Structures and Materials Symposium, Paper #5387-58, San Diego, CA, March 15-18, 2004.

35. S. Sherrit, X. Bao, Y. Bar-Cohen, and Z. Chang, "Resonance Analysis of High Temperature Piezoelectric Materials for Actuation and Sensing," SPIE Smart Struct. and Materials Symp., Paper #5388-34, San Diego, CA, March 15-18, 2004.

36. Y. Bar-Cohen, S. Sherrit, Z. Chang, L. Wessel, X. Bao, P. T. Doran, C. H. Fritsen, F. Kenig, C. P. McKay, A. Murray, and T. Peterson, "Subsurface Ice and Brine Sampling Using an Ultrasonic/Sonic Gopher for Life Detection and Characterization in the McMurdo Dry Valleys," Proceedings of the Industrial and Commercial Applications of Smart Structures Technologies Conference, SPIE Smart Structures and Materials Symposium, Paper #5388-32, San Diego, CA, March 15-18, 2004.

37. X. Bao, Y. Bar-Cohen, Z. Chang and S. Sherrit, "Characterization of bending EAP beam actuators," Proceedings of the EAPAD Conference, Paper #5385-50, SPIE Smart Structures and Materials Symposium, San Diego, CA, March 15-18,2004.

38. Y. Bar-Cohen, S. Sherrit, X. Bao, Z. Chang, and S.-S. Lih, "Enabling Novel Planetary and Terrestrial Mechanisms Using Electroactive Materials at the JPL’s NDEAA Lab," 2004 International Conference on MEMS, NANO, and Smart Systems (ICMENS 2004) Banff, Alberta, Canada, August 25 - 27, 2004.

39. S. Sherrit, M. Badescu, X. Bao, Y. Bar-Cohen, and Z. Chang, "Novel Horns for Power Ultrasonics," Proceedings of the IEEE International Ultrasonics Symposium, UFFC, Montreal, Canada, August 24-27, 2004.

40. S. Sherrit, M. Badescu, X. Q. Bao, Y. Bar-Cohen, and Z. Chang, "Efficient electromechanical network model for wireless acoustic-electric feedthroughs," Proceeding of the Smart Sensor Technology and Measurement Systems Conference, SPIE Smart Structures and Materials Symposium, Paper #5758-44, San Diego, CA, March 7 - 10, 2005.

41. X. Bao, Y. Bar-Cohen, Z. Chang, S. Sherrit, and M. Badescu, "Wirelessly controllable inflated electroactive polymer (EAP) reflectors," Proceeding of the EAPAD Conference, SPIE Smart Structures and Materials Symposium, Paper #5759-52, San Diego, CA, March 7 - 10, 2005.

42. Z. Chang, S. Sherrit, M. Badescu, X. Bao, and Y. Bar-Cohen, "Design and analysis of ultrasonic horn for a Ultrasonic/Sonic Driller/Corer (USDC)," Proceeding of the Industrial and Commercial Applications of Smart Structures Technologies, SPIE Smart Structures and Materials Symposium, Paper #5762-10, San Diego, CA, March 7 - 10, 2005.

43. Y. Bar-Cohen, Z. S. Chang, S. Sherrit, M. Badescu, X. Bao, "The Ultrasonic/Sonic Driller/Corer (USDC) as a subsurface drill, sampler, and lab-on-a-drill for planetary exploration applications," Proceeding of the Industrial and Commercial Applications of Smart Structures Technologies, SPIE Smart Structures and Materials Symposium, Paper #5762-21, San Diego, CA, March 7 - 10, 2005.

44. M. Badescu, Y. Bar-Cohen, X. Q. Bao, Z. Chang, B. E. Dabiri, B. A. Kennedy, and S. Sherrit, "Adapting the Ultrasonic/Sonic Driller/Corer (USDC) for walking/climbing robotic applications," Proceeding of the Industrial and Commercial Applications of Smart Structures Technologies, SPIE Smart Structures and Materials Symposium, Paper #5762-22, San Diego, CA, March 7 - 10, 2005.

45. M. Badescu, X. Bao, Y. Bar-Cohen, Z. Chang, S. Sherrit, "Integrated modeling of the Ultrasonic/Sonic Drill/Corer (USDC): procedure and analysis results," Proceeding of the Smart Structures and Integrated Systems, SPIE Smart Structures and Materials Symposium, Paper #5764-37, San Diego, CA, March 7 - 10, 2005.

46. Y. Bar-Cohen, S. Sherrit, M. Badescu, X. Bao, and Z. Chang, "Ultrasonic/Sonic Driller/Corer (USDC) as a Subsurface Sampler and Sensors Platform for Planetary Exploration Applications," European Geosciences Union, GI5 - Downhole Instrumentation: Technology and Applications, General Assembly 2005, Vienna, Austria, April 24-29, 2005.

47. S. Sherrit, B. J. Doty, M. Badescu, X. Bao, Y. Bar-Cohen and Z. Chang, "Efficient Electro-mechanical Network Model for Wireless Acoustic-Electric Feedthroughs," 2005 U.S. Navy Workshop on Acoustic Transduction Materials and Devices, State College, PA, May 10-12, 2005.

48. Y. Liu, C. Mavroidis, Y. Bar-Cohen, and Z. Chang, "Optimal design of the coring bit cutting edge in percussive / vibratory drilling," Proceedings of the 2005 ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference, held in Long Beach, California, September 24-28, 2005.

49. J. Aldrich, S. Sherrit, X. Bao, Y. Bar-Cohen, M. Badescu, Z. Chang, "Extremum-seeking control for an Ultrasonic/Sonic Driller/Corer (USDC) driven at high-power," SPIE Smart Structures and Materials Symposium, Paper #6166-45, San Diego, CA, Feb. 27 to March 2, 2006.

50. S. Sherrit, B. Doty, M. Badescu, X. Bao, Y. Bar-Cohen, J. Aldrich, Z. Chang, "Studies of Acoustic-Electric Feedthroughs for Power Transmission Through Structures," Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6171-02, San Diego, CA, Feb. 27 to March 2, 2006.

51. Z. Chang, S. Sherrit, M. Badescu, X. Bao, Y. Bar-Cohen, and P. Backes, "Reaction force of percussive corer, rotary-friction corer, and rotary-percussive corer," Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6171-06, San Diego, CA, Feb. 27 to March 2, 2006.

52. M. Badescu, S. Sherrit, A. Olorunsola, J. Aldrich, X. Bao, Y. Bar-Cohen, Z. Chang, P. T. Doran, C. H. Fritsen, F. Kenig, C. P. McKay, A. Murray, S. Du, T. Peterson, and T. Song, "Ultrasonic/sonic Gopher for subsurface ice and brine sampling: analysis and fabrication challenges, and testing results," Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6171-07, San Diego, CA, Feb. 27 to March 2, 2006.

53. X. Bao, Y. Bar-Cohen, Z. Chang, S. Sherrit and M. Badescu, "USDC based rapid penetrator of packed soil," Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6171-08, San Diego, CA, Feb. 27 to March 2, 2006.

54. X. Bao, Y. Bar-Cohen, Z. Chang, S. Sherrit and M. Badescu, "Rock Sampling using the Ultrasonic/Sonic Driller/Corer (USDC) for In-situ Planetary Exploration," 35th Annual UIA Symposium, San Diego, CA, March 13, 2006.

55. J. B. Aldrich, S. Sherrit, X. Bao, M. Badescu, Y. Bar-Cohen, Z. Chang, “Lyapunov stability of periodically modulated cosine drivers for resonance tuning of harmonic oscillators”, Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6523-10, San Diego, CA, March 18 to 22, 2007.

56. Y. Bar-Cohen, S. Sherrit, X. Bao, M. Badescu, J. Aldrich, and Z. Chang, “Subsurface sampler and sensors platform using the ultrasonic/sonic driller/corer (USDC)”, Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6529-18, San Diego, CA, March 18 to 22, 2007.

57. M. Badescu, S. Kassab, S. Sherrit, J. Aldrich, X. Bao, Y. Bar-Cohen, and Z. Chang, “Ultrasonic/sonic driller/corer as a hammer-rotary drill”, Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6529-26, San Diego, CA, March 18 to 22, 2007.

58. X. Bao, B. J. Doty, S. Sherrit, M. Badescu, Y. Bar-Cohen, J. Aldrich, and Z. Chang, “Wireless piezoelectric acoustic-electric power feedthru”, Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6529-134, San Diego, CA, March 18 to 22, 2007.

59. Z. Chang; X. Bao; B. J. Doty; S. Sherrit; Y. Bar-Cohen; M. Badescu; and J. Aldrich, “Power loss consideration in wireless piezoelectric acoustic-electric power feedthru”, Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6529-1836 San Diego, CA, March 18 to 22, 2007.

60. J. Su, E. H. Yang, T. Xu, R. M. Morgan, Z. Chang, “Active membrane using electrostrictive graft elastomer for deployable and lightweight mirrors,” SPIE Smart Structures and Materials and NDE for Health Monitoring and Diagonostics, , San Diego, CA, March 18 to 22, 2007.

61. Y. Bar-Cohen S. Sherrit, X. Bao, M. Badescu, J. Aldrich and Z. Chang, “Ultrasonic/Sonic Driller/Corer (USDC) as a Subsurface Sampler and Sensors Platform for Planetary Exploration Applications,” Proceedings of the NASA Science Technology Conference (NSTC-07), University of Maryland Conference Center, June 19-21, 2007.

62. Y. Bar-Cohen, S. Sherrit, X. Bao, M. Badescu, J. Aldrich, S.-S. Lih and Z. Chang, “Piezoelectric Materials as Enabling Actuators for Terrestrial and Planetary Mechanisms,” Invited Paper, Proceedings of the CANSMART 2007 - International Workshop Smart Materials and Structures, Montreal, Quebec, Canada, October 10, 2007.

63. E. H. Yang, Ji Su, T.-B. Xu, R. Morgan, and Z. Chang, "Active Membrane Using Electrostrictive Graft Elastomer for Deployable and Lightweight Mirrors ", ASME International Mechanical Engineering Congress and Exposition, Seattle, Washington, Nov 2007.

64. Y. Bar-Cohen, S. Sherrit, X. Bao, M. Badescu, J. Aldrich and Z. Chang, "The USDC as Subsurface Sampler and the challenges to insertion of new drilling technology in future missions," Workshop on Deep Mars: Accessing the subsurface of Mars on near term missions, NASA Ames, March 1-2, 2008.

65. S. Sherrit, X. Bao, M. Badescu, J. Aldrich, Y. Bar-Cohen, W. Biederman, and Z. Chang, “1KW Power Transmission using Wireless Acoustic-Electric Feed-through," Earth and Space Conference, Long Beach, CA, March 4, 2008.

66. X. Bao, W. Biederman, S. Sherrit, M. Badescu, Y. Bar-Cohen, C. Jones, J. Aldrich, and Z. Chang, “High-power piezoelectric acoustic-electric power feedthru for metal walls”, Proceeding of the SPIE Smart Structures and Materials Symposium, Paper #6930-36, San Diego, CA, March 9 to 13, 2008.

67. M. Badescu, S. Stroescu, S. Sherrit, J. Aldrich, X. Bao, Y. Bar-Cohen, Z. Chang, W. Hernandez, and A. Ibrahim, “Rotary hammer ultrasonic/sonic drill system,” Proceedings of the 2008 IEEE International Conference on Robotics and Automation (ICRA), Pasadena, CA, May 19-23, 2008.

68. M.J. Bruno, M. Badescu, R. Goullioud, B.P. Trease, Z. Chang, J.M. Carson, D.F. Braun, and B.T. Cook, “The Space Interferometer Siderostats,” IEEE Aerospace Conference, March 7-14, 2009.

69. M. Badescu, Y. Bar-Cohen, X. Bao, Z. Chang, K. Kerenyi, S.-S. Lih, S. Sherrit, B. P. Trease, and S. Widholm, “Direct measurement sensor of the boundary shear stress in fluid flow,” SPIE Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems Conference, Smart Structures and Materials Symposium, Paper 7647-48, San Diego, CA, March 8-11, 2010.

70. X. Bao, M. Badescu, Y. Bar-Cohen, S.-S. Lih, S. Sherrit, and Z. Chang, “Sensor for direct measurement of the boundary shear stress in fluid flow,” SPIE's 18th Annual International Symposium on Smart Structures/NDE, San Diego, CA, March 7-11, 2011.

71. S. Sherrit, L. Domm, X. Bao, Y. Bar-Cohen, Z. Chang, and M. Badescu, “Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill,” SPIE Smart Structures and Materials/NDE Symposium, held in San Diego, CA, March 12-16, 2012.

72. S. Sherrit, P.N. Ostlund, Z. Chang, X. Bao, Y. Bar-Cohen, S.E. Widholm, and M. Badescu, “Miniaturization of Planar Horn Motors,” SPIE Smart Structures and Materials/NDE Symposium, held in San Diego, CA, March 12-16, 2012.

73. M. Badescu, Y. Bar-Cohen, S. Sherrit, X. Bao, Z. Chang, C. Donnelly, and J. Aldrich, “Percussive Augmenter of Rotary Drills (PARoD),” SPIE Smart Structures and Materials/NDE Symposium, held in San Diego, CA, March 12-16, 2012.

74. R. Goullioud, D.A. Content, G.M. Kuan, J.D. Moore, Z. Chang, E.T. Sunada, J. Villalvazo, J.P. Hawk, E.L. Johnson, C.A. Powell, and N.V. Armani, “Wide field infrared survey telescope [WFIRST]: telescope design and simulated performance,” SPIE Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave, held in Amsterdam, Netherlands, July 1-6, 2012.

75. D. Content, K. Aaron, L. Abplanalp, K. Anderson, R. Capps, Z. Chang, J. Dooley, R. Egerman, R. Goullioud, D. Klein, J. Kruk, G. Kuan, M. Melton, J. Ruffa, M. Underhill, D. Van Buren, “Wide-Field InfraRed Survey Telescope (WFIRST) 2.4-meter mission study”, SPIE Optical Engineering + Applications, San Diego, California, September 26, 2013.

76. R.T. Demers, F. Dekens, R. Calvet, Z. Chang, R. Effinger, E. Ek, L Hovland, L Jones, A. Loc, B. Nemati, C. Noecker, T. Neville, H. Pham, M. Rud, H Tang, and J. Villalvazo, “Requirements and design reference mission for the WFIRST/AFTA coronagraph instrument”, SPIE Techniques and Instrumentation for Detection of Exoplanets VII, San Diego, CA, August 9, 2015.

77. N. Saini, K. Anderson, Z. Chang, G. Gutt, B. Nemati, “IMPipeline: an integrated STOP modeling pipeline for the WFIRST coronagraph”, SPIE Optics+Photonics Conference, San Diego, CA, August 8, 2017.

78. L.A.Tse, Z. Chang, R.P. Somawardhana, E.M. Slimko, “Structural, Thermal, and Optical Performance (STOP) Modeling and Analysis for the Surface Water and Ocean Topography Mission”, International Conference on Environmental Systems, Albuquerque, NM, July 8, 2018.