Bay in black  jacket near brick wall
Assistant Professor • Sylvia Norviel Cancer Research Faculty Fellow
Chemical and Biological Engineering

Office: JSCBB C224


B.S. in Materials Engineering, Rensselaer Polytechnic Institute (2014)
M.S. in Polymer Science and Engineering, UMass Amherst (2016)
Ph.D. in Polymer Science and Engineering, University of Massachusetts Amherst (2020)


  • MIT IMPACT Fellow (2021)
  • Stanford.Berkeley.UCSF Next Generation Faculty Symposium, Honorable Mention (2020)
  • MIT Chemical Engineering Rising Stars Participant (2020)
  • Princeton Presidential Postdoctoral Research Fellowship (2020 – Present)
  • APS FGSA Travel Award for Excellence in Graduate Research (2020)
  • NSF ASSIST Travel Grant (2020)
  • NSF ACADEME Travel Grant (2020)
  • Frank J. Padden Jr. Award Finalist, American Physical Society (APS)
  • Lighting the Pathway to Faculty Careers for Natives in STEM Fellowship (2019 – Present)
  • Eastman Chemical Student Award in Applied Polymer Science (2019)
  • NSF ACADEME Fellowship (2019)
  • GSOFT Travel Award, APS March Meeting (2019)
  • Best Poster Award, Annual Meeting of the Adhesion Society (2019)
  • Spaulding-Smith STEM Dissertation Fellowship, UMass Amherst (2019)
  • NEAGAP/IMSD Fellowship, UMass Amherst (2015 – 2016)

Selected Publications

  • A. Martínez-Calvo*, T. Bhattacharjee*, R.K. Bay, H.N. Luu+, A.M. Hancock, N.S. Wingreen, S.S. Datta, “Morphological instability and roughening of growing 3D bacterial colonies”, PNAS, 119, e2208019119 (2022).
  • ​R.K. Bay, T. Zhang, S. Shimomura, M. Ilton, K. Tanaka, R.A. Riggleman, A.J. Crosby, “Decoupling the impact of entanglements and mobility on the failure properties of ultrathin polymer films”, Macromolecules, 55(19), 8505-8514 (2022).
  • C. Chen, C.A. Airoldi, C.A. Lugo, R.K. Bay, B.J. Glover, A.J. Crosby, “Flower Inspiration: Broad-Angle Structural Color Through Tunable Hierarchical Wrinkles in Thin Film Multilayers”, Advanced Functional Materials, 2006256 (2020).
  • R.K. Bay*, K. Zarybnicka*, J. Jančář, A.J. Crosby, “Mechanical Properties of Ultrathin Film Nanocomposites”, ACS Applied Polymer Materials, 2(6), 2220-2227, (2020).
  • W.J. Choi*, R.K. Bay*, A.J. Crosby, “Tensile Properties of Ultrathin Bisphenol-A Polycarbonate Films”, Macromolecules, 52(19), 7489-7494, (2019).
  • R.K. Bay, A.J. Crosby, “Uniaxial Extension of Ultrathin Freestanding Polymer Films”, ACS Macro Letters, 8(9),1080-1085, (2019).
  • R.K. Bay, S. Shimomura, Y. Liu, M. Ilton, A.J. Crosby, “Confinement Effect on Strain Localization in Glassy Polymers”, Macromolecules, 51(10), 3647-3653 (2018).

Research Interests

The next generation of polymeric materials will need features typically associated with biological systems, such as programmable, self-healing, and self-regenerating properties. While engineering synthetic materials with such capabilities remains a grand challenge, these properties are inherent to biofilm-forming bacteria, which use internal material factories to produce polymeric matrices with highly precise and complex structures and mechanical properties. As such, our group, the Huli Materials Lab, leverages microorganisms to fabricate engineered living materials.

The Huli Materials Lab develops characterization and processing methods to quantify and program the properties of living polymeric materials to enable functionalities desired for applications in biotechnology, sensing, and protection. Research areas in the Huli Materials Lab include: (1) extreme mechanics of biofilms, (2) spatially programming the stimuli-responsive behaviors of living polymeric composites, and (3) engineering the mechanical properties of biohybrid hydrogels.