Zhengyang Liu, Ph.D.

SUMMARY

Highly accomplished Postdoctoral Associate with expertise in experimental and computational soft matter physics and fluid mechanics. Have a strong record of original research (15 publications including top journals like Nano Letters, Science Advances and PNAS, H-index 7), and a strong commitment to teaching and mentorship (mentored 10+ research students). Seeking a material research and development position / faculty position to leverage my research and teaching skills.

APPOINTMENTS

Cornell University. Postdoctoral Associate Mar. 2024 - Present

ESPCI Paris. Postdoctoral Associate Apr. 2021 - Jun. 2023

EDUCATION

University of Minnesota, Twin Cities. Chemical Engineering Ph.D. Aug. 2015 - Jan. 2021

Tsinghua University. Polymer Materials and Engineering B.S. Aug. 2010 - Jul. 2014

TRANSFERABLE SKILLS

• Laboratory skills: microscopy (confocal, fluorescence, bright-field), confocal displacement sensor, fluid characterizations, high speed imaging, Arduino microcontroller, Nanoscribe high precision 3D printing, surface coating, microfluidic device fabrication, genetic editing techniques, soft lithography techniques.
• Programming skills: Python (data analysis, GUI software, numerical simulation), MATLAB (image analysis), FORTRAN (numerical simulation), Linux HPC.
• Simulation skills: Dissipative Particle Dynamics (DPD), Finite Element Methods (FEM), Finite Difference Methods (FDM).
• Image analysis skills: Particle Image Velocimetry (PIV), particle tracking, orientation analysis, droplet detection.
• Other skills: theoretical analysis, CAD, 3D animations (Blender).

RESEARCH EXPERIENCES

Postdoctoral Associate | Bio-inspired Fluid Lab, CU Mar. 2024 - Present

• Project: Fringe Formation Around a Beet Slice
  • Employed a Keyence confocal displacement sensor to measure liquid surface profiles with micrometer precision.
  • Designed and constructed a custom surface scanner using Arduino microcontrollers and stepper motors.
  • Characterized liquid surface tension and viscosity using a tensiometer and vibration viscometer.
  • Analyzed data and processed images using Python and ImageJ.
  • Developed a numerical model of thin-film relaxation using Finite Difference Methods (FDM) in Python.
• Project: Acoustic-Driven Surface Cleaning with Millimeter-Sized Bubbles at Translational Resonance
  • Captured bubble dynamics during surface cleaning using a Photron high-speed camera.
  • Performed image-based bubble detection and statistical analysis using MATLAB and Python.
  • Developed a theoretical model predicting optimal acoustic frequencies based on bubble size and fluid properties.
• Project: Vapor Transport Flux around a Fungal Patch
  • Designed and constructed a custom environmental chamber using Arduino and humidity/temperature sensors.
  • Optimized lighting for droplet visualization in downstream image analysis.
  • Developed Python-based software for droplet detection and manual correction.
  • Quantified spatial distributions of vapor flux in the condensation processes around fungus colonies.

Postdoctoral Associated | PMMH & Gulliver Labs, ESPCI Apr. 2021 - Jun. 2023

• Project: Active Nematic Flows in Channel Networks
  • Fabricated custom microchannel networks using a Nanoscribe 3D printer.
  • Optimized surface coating protocols for active nematic preparation.
  • Imaged flow fields using a Nikon confocal microscope.
  • Extracted velocity and orientation fields using Particle Image Velocimetry (PIV) and structure tensor analysis, implemented in ImageJ and Python.
  • Developed a Finite Element Method (FEM) simulation in Python capturing the spontaneous flow phenomena.
• Project: Active Noise in Droplets of Bacterial Bath
  • Fabricated flow-focusing microfluidic devices using a Sutter micropipette puller.
  • Tracked tracer particle trajectories using a Lagrangian 3D Tracking Microscope (L3TM).
  • Performed droplet detection and quantitative image analysis using Python.

Research Assistant | Soft Matter Laboratory, UMN Sept. 2015 - Jan. 2021

• Project: Collective Motion in Bacterial Suspensions
  • Engineered a light-sensitive bacterial strain using genetic editing techniques, enabling optical control of motility.
  • Conducted PIV, density fluctuation, and energy spectrum analyses using Python.
  • Developed a Fourier-Transform-based algorithm to determine bacterial orientation from microscopy images.
  • Built a custom Python GUI tool for efficient manual correction of particle tracking data.
• Project: Rheology of bacterial suspensions under confinement
  • Fabricated microfluidic channels with varied geometries using soft lithography.
  • Conducted simultaneous measurements of rheology and microscopic dynamics using a custom microfluidic viscometer and confocal imaging.
  • Performed PIV, particle tracking, and statistical analysis using MATLAB.
  • Applied a theoretical model to explain confinement-induced changes in rheology.

Research Assistant | Soft Matter Simulation Laboratory, THU Sept. 2012 - Jul. 2014

• Project: Simulation of Entropy-Mediated Stimuli-Responsive Materials
  • Simulated grafted Janus particles at fluid interfaces using Dissipative Particle Dynamics (DPD) implemented in FORTRAN.
  • Executed and managed simulations in a Linux-based High Performance Computing (HPC) environment.
  • Visualized simulation output using MATLAB and PyMOL.
  • Conducted theoretical analysis of the results using a planar polymer brush model.

PUBLICATIONS

• Villalobos C.*, Liu Z.*, Ramos G., Goral M., Linder A., Lopez-León T., Clément E., Soto R. & Cordero M.-L.(2024) Active Bacterial Baths in Droplets. Accepted by PNAS.
• Lin Y.*, Liu Z.* & Jung S. (2025) Acoustic-Driven Surface Cleaning with Millimeter-Sized Bubbles at Translational Resonance. preprint.
• Fu Y., Liu Z., Tandon S., Gelfand J. & Jung S. (2025) Vortex transition and thermal mixing by pitching a perforated flexible panel. preprint.
• Liu Z., Fu Y., Maitra A., Kumar K., Chen J. & Jung S. (2025) Fringe around a Beet Slice: Wetting-induced Dimple in a Thin Liquid Film. Physical Review Fluids 10, 064004. (Editors’ Suggestion)
• Qiao Y., Liu Z., Ma X., Keim N. C. & Cheng X. (2023) Heterogeneous Dynamics of Sheared Particle-Laden Fluid Interfaces with Janus Particle Doping. Langmuir 39(34):12032–12040.
• Ma X., Liu Z., Zeng W., Lin T., Tian X. & Cheng X.(2022) Crack patterns of drying dense bacterial suspensions Soft Matter 18(28):5239–5248.
• Qiao Y., Ma X., Liu Z., Manno MA, Keim N. C. & Cheng X.(2022) Tuning the rheology and microstructure of particle-laden fluid interfaces with Janus particles Journal of Colloid and Interface Science 618:241–247.
• Liu Z., Zeng W., Ma X. & Cheng X. (2021) Density fluctuations and energy spectra of 3D bacterial suspensions. Soft Matter 17(48):10806–10817. (Cover)
• Peng Y., Liu Z. & Cheng X. (2021) Imaging the emergence of bacterial turbulence: Phase diagram and transition kinetics. Science Advances 7(17):eabd1240.
• Qiao Y., Fan C., Liu Z., Medina D., Keim N. C. & Cheng X. (2021) Miniature magnetic rod interfacial stress rheometer for general-purpose microscopes. Journal of Rheology 65(6):1103–1110.
• Liu Z.. (2021) Novel Properties and Emergent Collective Phenomena of Active Fluids. PhD thesis
• Liu Z., Zhang K. & Cheng X. (2019) Rheology of bacterial suspensions under confinement Rheologica Acta 58(8):439–451.
• Yang O.*, Peng Y.*, Liu Z., Tang C., Xu X. & Cheng X. (2016) Dynamics of ellipsoidal tracers in swimming algal suspensions. Physical Review E 94(4):042601.
• Liu Z.*, Guo R.*, Xu G., Huang Z. & Yan L.-T. (2014) Entropy-Mediated Mechanical Response of the Interfacial Nanoparticle Patterning. Nano Letters 14(12):6910–6916.
• Guo R., Liu Z., Xie X.-M. & Yan L.-T. (2013) Harnessing Dynamic Covalent Bonds in Patchy Nanoparticles: Creating Shape-Shifting Building Blocks for Rational and Responsive Self-Assembly. Journal of Physical Chemistry Letters 4(8):1221–1226.

CONFERENCE PRESENTATIONS

• Liu Z., Fu Y., Maitra A., Kumar K., Chen J. & Jung S. (2024) Fringe around a Beet Slice. APS DFD Meeting.
• Liu Z., Dore C., Tavera-Vazquez A., Lopez-Leon T. (2023) Active Nematics in Channel Networks. Workshop Defects and Self-Organization.
• Liu Z. & Clement E. (2022) Collective Motion and Reversible Jamming in a Droplet. Journées de Physique Statistique.
• Liu Z. Villalobos C., Cordero M.-L., Soto R., Lopez-Leon T., Linder A. & Clement E. (2022) Collective Bacterial Dynamics in Curved Spaces CNRS MITI.
• Liu Z., Villalobos C., Cordero M.-L., Soto R., Lopez-Leon T., Linder A. & Clement E. (2022) Bacterial Dynamics in Curved Spaces. Active and Living Matter Days.
• Liu Z., Nagendra K., Brujic J. & Clement E. (2022) Swimming in a 2D Porous Media. AMCM Summer School.
• Liu Z., Peng Y. & Cheng X. (2020) Imaging the Swarming Transition Using Light-Controlled Bacteria. APS March Meeting.
• Liu Z., Zeng W., Ma X. & Cheng X. (2020) Giant Number Fluctuations in 3D Bacterial Active Turbulence. APS DFD Meeting.
• Liu Z., Zhang K. & Cheng X. (2019) Rheology of Confined Bacterial Suspensions. SOR Meeting.
• Liu Z., Zhang K. & Cheng X. (2019) Rheology of bacterial suspensions under confinement. APS March Meeting.
• Liu Z., Zhang K. & Cheng X. (2018) Viscosity of confined bacterial suspensions SOR Meeting.
• Liu Z., Peng Y. & Cheng X. (2017) Diffusion, Viscosity and Collective Motions in Bacterial Suspensions. Georgetown Active Matter Summer School.

TEACHING EXPERIENCES

• Biorobotics (2025) Teaching assistant, Cornell University.
• Senior chemical engineering lab (2019) Teaching assistant, University of Minnesota.
• Biochemical engineering (2018) Teaching assistant, University of Minnesota.
• Transport phenomena (2016) Teaching assistant, University of Minnesota.

AWARDS

• Society of Rheology Student Travel Grant (2019) SoR Annual Meeting, Raleigh, NC.
• Frank & Janis Bates Research Fellowship Fund (2015) University of Minnesota, Minneapolis, MN.