I am an experimental physicist, with broad research interests in fluidic behaviour and soft matter physics.
I began my research career as a PhD student at NTU, focusing on polymeric and droplet dynamics, in particular, aqueous polymer solutions that dry to form structures which deviate from the common "coffee-ring" deposit, and instead can grow pillars up to 3x their initial droplet height as the polymer undergoes a phase transition. As the coffee-ring effect is a particular problem to the ink-jet printing industry, the explanation of this behaviour has received significant attention. Since then, as a post-doctoral researcher, I have stayed within the realm of soft matter physics, exploring: the shapes of levitating, spinning droplets relevant to the geophysical phenomenon of tektite formation; the inhibition of a magnetically induced Rayleigh-Taylor instability by rotational Coriolis forces; vibration induced self-propulsion of a two-sphere dimer; and active emulsions, where droplets swim as the system evolves from an out-of-equilibrium state into a nano-emulsion. The latter has further branched my experience into liquid crystals, which can be used to modify the swimming behaviour via a cascade of symmetry-breaking.
There is a rich tapestry of problems to be solved in fluid dynamics and soft matter physics, and pondering these unanswered questions keeps my neurons firing, and my enthusiasm high. It is a constant source of amazement to me that, with some pumps, liquids, dyes and magnets, one can gain insight into a wide variety of seemingly unrelated physical phenomena, such as tectonic drift, atomic fission, and even supernovae.
Publications (link to Google Scholar profile):
- Chemotactic droplet swimmers in complex geometries, Journal of Physics: Condensed Matter, 2018.
- Magnetically Induced Rotating Rayleigh-Taylor Instability, Journal of Visualized Experiments, 2017.
- The Rotating Rayleigh-Taylor Instability, Physical Review Fluids, 2017. (ArXiV version)
- Propulsion of a Two-Sphere Swimmer, Physical Review Letters, 2015. (ArXiV version)
- The Inhibition of the Rayleigh-Taylor Instability by Rotation, Scientific Reports, 2015.
- Classifying Dynamic Contact Lines in Drying Drops. Soft Matter, 2015.
- Artificial tektites: an experimental technique for capturing the shapes of spinning drops, Scientific Reports, 2015.
- Imaging internal flows in a drying sessile polymer dispersion drop using Spectral Radar Optical Coherence Tomography (SR-OCT), Journal of Colloid and Interface Science, 2013.
- Monolith formation and ring-stain suppression in low-pressure evaporation of poly(ethylene oxide) droplets, Journal of Fluid Mechanics, 2012.
- The effects of molecular weight, evaporation rate and polymer concentration on pillar formation in drying poly(ethylene oxide) droplets, Colloids and Surfaces A, 2012.
- Drying and deposition of poly(ethylene oxide) droplets determined by Péclet number, Soft Matter, 2011.
- Growth of solid conical structures during multistage drying of sessile poly(ethylene oxide) droplets, Physical Chemistry Chemical Physics, 2010.