Miniaturized sensors and actuators may be used to shrink medical devices for use in endoscopic imaging applications, in collaboration with the group of Thomas D. Wang, Internal Medicine, University of Michigan.

Research topics include:

  • Scanning actuators for multi-photon endomicroscopy:  Design, analysis, fabrication, and control of thin-film and bulk piezoelectric actuators designed to performing targetable z-axis scanning of femtosecond lasers during deep-tissue multiphoton imaging.
  • Scanning actuators for dual-axis confocal microscopy:  Thin- and thick-film MEMS actuators designed to provide z-axis motion for a dual-axis confocal microscope, to allow in-vivo cross-sectional imaging of tissue through an endoscope.
  • Dynamic modeling of electrostatic micro-actuators: Dynamic analysis of large-deflection, parametrically-resonant electrostatic microactuators for a variety of endomicroscopic imaging instruments, with Dr. Haijun Li (Wang group).

As an example of potential capabilities, dual-axis confocal microscopy permits deeper imaging penetration into tissue than most other microscopy techniques.  By shrinking the scanning components of such systems, cross-sectional images of tissue (as in the schematic below) could be obtained during endoscopic examination, without need for physical biopsies.   An example piezoelectrically-actuated micro-mirror and sample cross-sectional images of fluorescent beads and excised mouse colon tissue are shown below, acquired with a benchtop prototype multi-photon imaging system.

Actuators under development and study include:

  • Thin-film piezoelectric vertical actuator for dual-axes confocal microscopy (below)
  • Bulk piezoelectric miniature translational actuator for multiphoton microscopy
  • Electrostatic parametrically-resonated scanning mirrors, in collaboration with Thomas D. Wang group, University of Michigan Department of Biomedical Engineering
  • Wireless permalloy electromagnetic actuators
  • Electrothermal actuator testbeds for processing and control

Collaborators:  Prof. Thomas Wang, M.D., Michigan Biomedical Engineering

Center for Optical Imaging

Previous Collaborators (via NIH NTR/BRP and other prior programs):

Prof. Katsuo Kurabayashi, Mechanical Engineering

Prof. Gary Luker, Radiology

Prof. Eric Fearon, Internal Medicine

Prof. Albert Shih, Mechanical Engineering

Sponsors: National Institutes of Health, National Science Foundation

Related Publications:

  1.  G. Li, X. Duan, M. Lee, M. Birla, J. Chen, K.R. Oldham, T.D. Wang, H. Li, “Ultra-compact microsystems-based confocal endomicrosope,” IEEE Transactions on Medical Imaging, vol. 39, no. 7, 2020. (pdf)
  2.  Y. Chen, M. Lee, M.B. Birla, H. Li, G. Li, X. Duan, T.D. Wang, and K.R. Oldham, “Motion estimation for a compact microscanner via shared driving and sensing electrodes in endomicroscopy,” IEEE/ASME Transactions on Mechatronics, vol. 25, no. 2, 2020). (pdf)
  3. H. Li, P. Barnes, E. Harding, X. Duan, T.D. Wang, and K.R. Oldham, “Large-displacement vertical electrostatic microactuator dynamics using duty-cycled softening/stiffening parametric resonance,” Journal of Microelectromechanical Systems, vol. 28, no 3 (2019). (pdf)
  4.  H. Li, K.R. Oldham, and T.D. Wang, “3 degree-of-freedom resonant scanner with full circumferential range and large out-of-plane displacement,” Optics Express, vol. 27, no. 11 (2019). (pdf)
  5.  Y. Chen, H. Li, Z. Qiu, T.D. Wang, K.R. Oldham, “Improved extended Kalman filter estimation using threshold signal detection with a MEMS electrostatic micro-scanner,” IEEE Transactions on Industrial Electronics, vol. 67, no. 2, 2020. (pdf)
  6. J. Choi, T. Wang, K. Oldham, “Dynamics of thin-film piezoelectric microactuators with large vertical stroke subject to multi-axis coupling and fabrication asymmetries,”Journal of Micromechanics and Microengineering, vo. 28, 2018. (pdf)
  7. X. Duan, H. Li, F. Wang, X. Li, K.R. Oldham and T.D. Wang, “Three-dimensional side-view endomicroscope for tracking individual cells in vivo,” Biomedical Optics Express, vol. 8, no. 12, pp. 5533-5545, 2017. (pdf)
  8. J. Choi, X. Duan, H. Li, T.D Wang, K.R. Oldham, “Multi-photon imaging with thin-film piezoelectric actuator,” PP, IEEE Journal of Microelectromechanical Systems, 2017. (pdf)
  9. G. Li, H. Li, X. Duan, Q. Zhou, J. Zhou, K. R. Oldham, T. D. Wang, “Visualizing epithelium molecular expression in vertical and horizontal planes with dual axes confocal endomicroscope using compact distal scanner,” PP, IEEE Transactions on Medical Imaging, 2017. (pdf)
  10. H. Li, X. Duan, G. Li, K. R. Oldham, and T.D. Wang, “An electrostatic MEMS translational scanner with large out-of-plane stroke for remote axial-scanning in multi-photon microscopy,” Micromachines, vol. 8, no. 5, pp. 159-167, 2017. (pdf)
  11. X. Duan, H.Li, G. Li, K.R. Oldham, and T.D. Wang, “Axial beam scanning in multiphoton microscopy with MEMS-based actuator,” Optics Express, vol. 25, no. 3, pp. 2195-2205, 2017. (pdf)
  12. X. Duan, H. Li, J. Zhou, Q. Zhou, K. R. Oldham, T. D. Wang, “Visualizing epithelial expression of EGFR in vivo with a distal scanning side-viewing confocal endomicroscope,” Scientific Reports, vol. 6, 37315, 2016. (pdf)
  13. H. Li, X. Duan, Z. Qiu, Z. Quan, K. Kurabayashi, K.R. Oldham, T.D. Wang, “Integrated monolithic 3D MEMS scanner for switchable real-time vertical/horizontal cross-sectional imaging,” Optics Express, vol. 24, no. 3, pp. 2145-2155, 2016. (pdf)
  14. X. Duan, H.Li, Z. Qiu, B.P. Joshi, A. Pant, A. Smith, K. Kurabayashi, K.R. Oldham, T.D. Wang, “MEMS-based multiphoton endomicroscope for repetitive imaging of mouse colon,” Biomedical Optics Express, vol. 6, no. 8, pp. 3074-3083, 2015. (pdf)
  15. J. Choi, Z. Qiu, C.-H. Rhee, T.D. Wang, and K.R. Oldham, “A three-degree-of-freedom thin-film PZT-actuated microactuator with a large out-of-plane displacement,” Journal of Micromechanics and Microengineering, vol. 24, no. 7, 075017, 2014 (pdf)
  16. W. Shahid, X. Duan, Z. Qiu, H. Li, T.D. Wang, and K.R. Oldham, “Modeling, simulation, and control of a parametrically resonant micro-mirror with duty-cycled excitation,” IEEE Journal of Microelectromechanical Systems, vol. 23, no. 6, pp. 1440-1453, 2014. (pdf)
  17. Z. Qiu, S. Khondee, X. Duan, H. Li, M.J. Mandella, B.P. Joshi, Q. Zhou, S.R. Owens, K. Kurabayashi, K.R. Oldham, and T.D. Wang, “Vertical cross-sectional imaging of colonic dysplasia in vivo with multi-spectral dual axes confocal endomicroscopy,” Gastroenterology, vol. 146, no. 3, pp. 615-617, 2014. (pdf)
  18. Z. Qiu, C.-H. Rhee, J. Choi, T.D. Wang, and K.R. Oldham, “Large stroke vertical PZT microactuator with high-speed rotational scanning,” Journal of Microelectromechanical Systems, vol. 23, no. 2, pp. 256-258, 2014. (pdf)
  19. E.N. Sihite, Z. Qiu and K.R. Oldham, “Modeling and control of optical fiber micropositioning in a thermal adhesive,” Proceedings of the 2013 American Controls Conference, Washington, DC, July 2013. (pdf)
  20. Z. Qiu, Z. Liu, X. Duan, B. Joshi, M. Mandella, K. Oldham, K. Kurabayashi, and T. Wang, “Targeted vertical cross-sectional imaging with handheld near-infrared dual axes confocal fluorescence microscope,” Biomedical Optics Express, 4(1), 322-330, 2012. (pdf)
  21. J.F. Domke, C.-H. Rhee, Z. Liu, T.D. Wang, and K.R. Oldham, “Amplifying Transmission and Compact Suspension for a Low-Profile, Large Displacement Piezoelectric Actuator,” Journal of Micromechanics and Microengineering, 21(6) 067004 (2011) (pdf)
  22. Z. Qiu, X. Lin, T. Wang, and K. Oldham, “Large Displacement Vertical Translational Actuator Based on Piezoelectric Thin Films,” Journal of Micromechanics and Microengineering, 20(7) 075016 (2010) (pdf)
  23. K. Oldham, Z. Qiu, X. Lin, J.S. Pulskamp, and R.G. Polcawich, “Dynamics, Sensing, and Control of a Thin-Film Piezoelectric Vertical Micro-Stage,” Proceedings of the ASME Dynamic Systems and Control Conference, Boston, MA (2010)