@article{thelen_dickey_ward_2012, title={A study of the production and reversible stability of EGaIn liquid metal microspheres using flow focusing}, volume={12}, ISSN={["1473-0197"]}, DOI={10.1039/c2lc40492c}, abstractNote={This manuscript describes an experimental study of the production of micro-scale droplets of the room-temperature liquid alloy eutectic gallium indium (EGaIn) formed using a microfluidic flow-focusing device. The EGaIn surface oxidizes readily to form a passivating oxide "skin" that imparts some mechanical stability to the resulting microspheres, but does not appear to affect the dynamics of droplet formation. EGaIn has an interfacial tension nearly an order of magnitude larger than typical water-in-oil systems that are used to study droplet production in microfluidic flow-focusing devices. The size of the microdroplets increase as the ratio of the flow rates of the dispersed and continuous-phase increase for both EGaIn-in-glycerol and water-in-oil systems; however, these fluid pairs form droplets through different dispersing modes at otherwise identical flow conditions (i.e., flow rate ratios and capillary numbers). Consequently, the EGaIn droplets are larger than the water droplets. The difference in dispersing modes and droplet size are attributed to the relatively larger interfacial and inertial forces of the EGaIn system compared to the water-in-oil system. The addition of polyvinyl alcohol (PVA), which is known to bind to oxide surfaces, to the continuous phase yields stable, monodisperse emulsions of liquid metal. These emulsions can be destabilized on demand by changing the solution pH, allowing the liquid metal to be recovered. The ability of the PVA to bind to the liquid metal also influences droplet production by changing the shape of the liquid as it approaches the orifice of the flow focusing device, which results in droplets with smaller diameters relative to those formed without PVA.}, number={20}, journal={LAB ON A CHIP}, publisher={Royal Society of Chemistry (RSC)}, author={Thelen, Jacob and Dickey, Michael D. and Ward, Thomas}, year={2012}, pages={3961–3967} }
 @article{white_ward_2012, title={CO2 sequestration in a radial Hele-Shaw cell via an interfacial chemical reaction}, volume={22}, number={3}, journal={Chaos (Woodbury, N.Y.)}, author={White, A. R. and Ward, T.}, year={2012} }
 @article{ward_hourigan_2012, title={Granular segregation in a tilted-rotating drum}, volume={215-16}, journal={Powder Technology}, author={Ward, T. and Hourigan, W.}, year={2012}, pages={227–234} }
 @article{ward_white_2011, title={Gas-driven displacement of a liquid in a partially filled radial Hele-Shaw cell}, volume={83}, number={4}, journal={Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics}, author={Ward, T. and White, A. R.}, year={2011} }
 @article{ward_2010, title={Capillary-pressure driven adhesion of rigid-planar surfaces}, volume={354}, number={2}, journal={Journal of Colloid and Interface Science}, author={Ward, T.}, year={2010}, pages={816–824} }
 @article{ward_faivre_stone_2010, title={Drop production and tip-streaming phenomenon in a microfluidic flow-focusing device via an interfacial chemical reaction}, volume={26}, number={12}, journal={Langmuir}, author={Ward, T. and Faivre, M. and Stone, H. A.}, year={2010}, pages={9233–9239} }
 @article{grunewald_levy_mata_ward_bertozzi_2010, title={Self-similarity in particle-laden flows at constant volume}, volume={66}, number={1-3}, journal={Journal of Engineering Mathematics}, author={Grunewald, N. and Levy, R. and Mata, M. and Ward, T. and Bertozzi, A. L.}, year={2010}, pages={53–63} }
 @article{ward_hourigan_2009, title={Experimental investigation of transition to laminar mixing of a homogeneous viscous liquid in a tilted-rotating tank}, volume={64}, ISSN={["0009-2509"]}, DOI={10.1016/j.ces.2009.07.032}, abstractNote={A tilted and partially filled rotating tank is investigated experimentally at O(1) Reynolds and small (⪡1) capillary numbers, to study the mixing of a viscous homogeneous fluid. Of particular interest is the transition from a previously studied low Reynolds number flow regime [Ward, T., Metchik, A., 2007. Viscous fluid mixing in a titled tank by periodic shear. Chemical Engineering Science 62, 6274–6284], that exhibited two large vortices, to the laminar flow regime which results in additional vortex generation. In the laminar Reynolds number limit O(1) the two primary vortices generated by the liquid rotation axis can interact with the bottom wall, generating two secondary counter-rotating vortices, via a cascade that is qualitatively similar to the well known Moffatt [1964. Viscous and resistive eddies near a sharp corner. Journal of Fluid Mechanics 18, 1–18] vortices in Stokes flow. While the secondary vortices aid in transporting material from the walls to the bulk, they also intensify in magnitude with increasing rotation rate leading to finite sized unmixed regions via the appearance of KAM-like surfaces [Alvarez-Hernández, M.M., Shinbrot, T., Zalc, J., Muzzio, F.J., 2002. Practical chaotic mixing. Chemical Engineering Science 57, 3749–3753]. This suggests that there may be an optimal tilt angle, for a given speed, with which to achieve the maximum mixed cross sectional area within a minimum amount of elapsed time. Experiments are performed using a 90% glycerol, 10% water mixture at two volume portions with angles ranging between 25∘ and 65∘ measured from the horizontal. Laser fluorescence is used to illuminate the vortices via experimental Poincaré mapping [Fountain, G.O., Khakhar, D.V., Ottino, J.M., 1998. Visualization of three dimensional chaos. Science 281, 683–686], and the resulting images are analyzed to determine the mixed cross sectional area versus elapsed time.}, number={23}, journal={CHEMICAL ENGINEERING SCIENCE}, author={Ward, Thomas and Hourigan, William}, year={2009}, month={Dec}, pages={4919–4928} }
 @article{ward_wey_glidden_hosoi_bertozzi_2009, title={Experimental study of gravitation effects in the flow of a particle-laden thin film on an inclined plane}, volume={21}, number={8}, journal={Physics of Fluids (Woodbury, N.Y.)}, author={Ward, T. and Wey, C. and Glidden, R. and Hosoi, A. E. and Bertozzi, A. L.}, year={2009} }