Stefan Idziak

Stefan Idziak
Associate Professor, Associate Dean of Science, Computing and Co-operative Education, Undergraduate Advisor
Location: PHY 250
Phone: 519-888-4567 x45580


Stefan Idziak studies complex fluids using X-ray diffraction.

Research Interests

  • Complex fluids
  • Confinement
  • Synchrotron x-ray diffraction
  • Devices and Analytical Methods

Scholarly Research

Confinement of complex fluid systems between two surfaces or in narrow pores is known to strongly alter the collective structure of the trapped molecules in fluids composed of molecular aggregates such as polymers, vesicles, biomembranes, or colloidal particles suspended in the liquid. The understanding of these new fluid properties is both of intrinsic and practical interest ranging from thin film lubrication to catalysis and separations. The X-Ray Surface Forces Apparatus (XSFA) is capable of imaging. Research projects include, 1. using the XSFA to study the effects of lubrication on wear;, 2. the investigation of the structure of flowing complex fluids; and, 3. the study of novel complex fluid and membrane systems., This work is conducted using both in-house x-ray diffraction facilities as well as high resolution synchrotron diffraction techniques.


  • 1992 PhD Physics, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A.
  • 1986 BSc Physics, McGill University, Montréal, Québec, Canada


  • 2000 Premier's Research Excellence Award


  • 2010 - present: Judge-in-chief, Waterloo Wellington Science and Engineering Fair

Professional Associations

  • 2007: Chair, Division of Condensed Matter and Materials Physics, Canadian Association of Physicists
  • 2003 - 2012: Secretary, Canadian Institute for Synchrotron Radiation

Affiliations and Volunteer Work

  • Associate Dean of Science, Special Projects
  • Centre for Bioengineering and Biotechnology


  • PHYS 112 - Physics 2
    • Taught in 2019, 2020, 2021, 2022, 2023
  • SCI 206 - The Physics of How Things Work
    • Taught in 2019, 2020, 2021, 2022

* Only courses taught in the past 5 years are displayed.

Selected/Recent Publications

  • Mazzanti G, Guthrie SE, Sirota EB, et al. Orientation and phase transitions of fat crystals under shear CRYST GROWTH DES 3 (5): 721-725 SEP-OCT 2003
  • Welch SE, Stetzer MR, Hu G, et al. Intermembrane spacing and velocity profiling of a lamellar lyotropic complex fluid under flow using x-ray diffraction PHYS REV E 65 (6): Art. No. 061511 Part 1 JUN 2002
  • Idziak SHJ, Welch SE, Kisilak M, et al. Undulating membrane structure under mixed extensional-shear flow EUR PHYS J E 6 (2): 139-145 OCT 2001
  • Kisilak M, Anderson H, Babcock NS, et al. An x-ray extensional flow cell REV SCI INSTRUM 72 (11): 4305-4307 NOV 2001
  • Warriner HE, Keller SL, Idziak SHJ, et al. The influence of polymer molecular weight in lamellar gels based on PEG-lipids BIOPHYS J 75 (1): 272-293 JUL 1998


  • Marangoni, A.G., Idziak, S.H.J., Food Product, 2006. Canada and Brazil Patent Application.
  • Marangoni, A.G., Idziak, S.H.J., Food Product, 2005. U.S.A. and International Patent Application.
  • Marangoni, A.G., Idziak, S.H.J., 2005. Spreadable Food Product [US] Patent patent-number 20050249855, filed May 7, 2004 (issued, 2005).
  • Safinya, C.R., Warriner, H.E., Idziak, S.H.J., 2005. Lamellar Gels and Methods for Making and Regulating [US] Patent patent-number 6,899,895, filed January 4, 2001 (issued, 2005).
  • Safinya, C.R., Warriner, H.E., Idziak, S.H.J., 2005. Lamellar Gels and Methods for Making and Using [US] Patent patent-number 6,207,186, filed February 13, 1998 (issued, 2001).

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