Electrohydrodynamics of Nonequilibrium Patterns and Emergence of Organized States in Confined Liquids
Project Description
Spontaneous emergence of organized states is of significant fundamental and technological interest because of the difficulty in predicting them and potential use in applications. Electric fields can deform drops into cones. Fine jets, which are emitted from these pointed-protrusions, break into microdrops. Exploitation of this phenomenon resulted in a Nobel for discovery of electrospray-ionization-mass-spectrometry (EIMS). EIMS’s success led to studies of drops deforming prolately (parallel to the applied field). Researchers also showed that drops can deform oblately (perpendicular to the applied field). As field strength increases, oblate drops exhibit three instabilities: Quincke rotation, dimpling and lens formation. Dimpled-drops pinch to form tori. Lenticular-drops emit equatorial sheets. Disintegration of sheets produces microdrops, a potential game-changer for forming emulsions. If breakup is prevented, streaming can produce novel-shaped particles. However, drops of one phase must be dispersed in a second phase to exploit oblate/prolate deformations. Recently, it was discovered accidentally that not only the aforementioned outcomes but additional dynamics including spontaneous formation of organized states can be realized by confining two phases that are separated by a single interface. This project’s goal is to explore the use of electric fields to induce electrohydrodynamically driven deformation, instability, and pattern formation in such systems.
Start Date
Spring (or summer) semester 2026
Postdoc Qualifications
Expertise in theoretical and simulation techniques in general and fluid mechanics in particular. A PhD in chemical, mechanical or a closely related engineering discipline, physics, or mathematics. Familiarity with electrohydrodynamics or ferrohydrodynamics is highly desirable but not required.
Co-advisors
Primary faculty co-advisor: Osman Basaran, obasaran@purdue.edu, Chemical Engineering
Second faculty co-advisor: Ivan Christov, christov@purdue.edu, Mechanical Engineering
Bibliography
Collins, R. T., Jones, J. J., Harris, M. T., and Basaran O. A. 2008 Electrohydrodynamic tip streaming and emission of charged drops from liquid cones. Nature Phys. 4, 149-154.
Vlahovska, P. M. 2019 Electrohydrodynamics of drops and vesicles. Annu. Rev. Fluid Mech. 51 (1), 305-330.
Raju, G., Kyriakopoulos, N., and Timonen, J. V. I. 2021 Diversity of non-equilibrium patterns and emergence of activity in confined electrohydrodynamically driven liquids. Sci. Adv. 7(38): eabh1642.
Anthony, C. R., Wee, H., Garg, V., Thete, S. S., Kamat, P. M., Wagoner, B. W., Wilkes, E. D., Notz, P. K., Chen, A. U., Suryo, R., Sambath, K., Panditaratne, J. C., Liao, Y.-C., and Basaran, O. A. 2023 Sharp interface methods for simulation and analysis of free surface flows with singularities: breakup and coalescence. Annu. Rev. Fluid Mech. 55, 707-747.
Yu, Z. and Christov, I. C. 2023 Delayed Hopf bifurcation and control of a ferrofluid interface via a time-dependent magnetic field. Phys. Rev. E 107 (5), 055102.