2020

• Hassan, M. R., & Wang, C. (2020). Ferro-hydrodynamic interactions between ferrofluid droplet pairs in simple shear flows. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 124906.

• Hassan, M. R., & Wang, C. (2020). Lateral migration of a ferrofluid droplet in a plane Poiseuille flow under uniform magnetic fields. Physical Review E, 102(2), 022611.

• Li, L., Wang, C., Nie, Y., Yao, B., & Hu, H. (2020). Nanofabrication Enabled Lab-on-a-Chip Technology for the Manipulation and Detection of Bacteria. TrAC Trends in Analytical Chemistry, 115905.

• Sobecki, C., Zhang, J. & Wang, C. (2020). Numerical Study of Paramagnetic Elliptical Microparticles in Curved Channels and Uniform Magnetic Fields. Micromachines. https://www.mdpi.com/2072-666X/11/1/37/htm

2019

• Hassan, M. R., Wang, C. (2019). Magnetic field induced ferrofluid droplet breakup in a simple shear flow at a low Reynolds number. Physics of Fluids. https://aip.scitation.org/doi/full/10.1063/1.5124134

• Sobecki, C., Zhang, Y., & Wang, C. (2019). Three-dimensional rotation of paramagnetic and ferromagnetic prolate spheroids in simple shear and uniform magnetic field. Physics of Fluids (Editor's Pick). https://aip.scitation.org/doi/full/10.1063/1.5123596

• Mingxing Zhou, Ziyue Wu, Yicong Zhao, Qing Yang, Wei Ling, Ya Li, Hang Xu, Cheng Wang, Xian Huang (2019). Droplets as Carriers for Flexible Electronic Devices. Advanced Science. https://onlinelibrary.wiley.com/doi/pdf/10.1002/advs.201901862

• Zhang, J., Zhou, R., & Wang, C. (2019). Dynamics of a pair of ellipsoidal microparticles under uniform magnetic fields. Journal of Micromechanics and Microengineering. https://doi.org/10.1088/1361-6439/ab3432

This work numerically investigated the particle-particle interactions and relative motions of a pair of paramagnetic elliptical particles by using the direct numerical simulations.

• Li, L., Tian, F., Chang, H., Zhang, J., Wang, C., Rao, W., & Hu, H. (2019). Interactions of Bacteria With Monolithic Lateral Silicon Nanospikes Inside a Microfluidic Channel. Frontiers in Chemistry, 7, 483. https://doi.org/10.3389/fchem.2019.00483

We demonstrated a simple and novel approach to manipulate droplet migration in microfluidics by using a uniform magnetic field.

• Zhang, J., Hassan, M. R., Rallabandi, B., & Wang, C. (2019). Migration of ferrofluid droplets in shear flow under a uniform magnetic field. Soft Matter. https://doi.org/10.1039/C8SM02522C

We demonstrated a simple and novel approach to manipulate droplet migration in microfluidics by using a uniform magnetic field.

2018

• Behdani, B., Monjezi, S., Carey, M. J., Weldon, C. G., Zhang, J., Wang, C., & Park, J. (2018). Shape-based separation of micro-/nanoparticles in liquid phases. Biomicrofluidics, 12(5), 051503.

We review various up-to-date approaches to shape-based separation of rigid micro-/ nanoparticles in liquid phases including size exclusion chromatography, field flow fractionation, deterministic lateral displacement, inertial focusing, electrophoresis, magnetophoresis, self-assembly precipitation, and centrifugation.

• Hassan, M. R., Zhang, J., & Wang, C. (2018). Deformation of a ferrofluid droplet in simple shear flows under uniform magnetic fields. Physics of Fluids, accepted. (IF: 2.279)

This research shows a simple, novel and flexible way to control the deformation of a ferrofluid droplet by combining shear flow and a magnetic field. We study the effects of magnetic bond number, capillary number and direction of magnetic field.

• Sobecki, C., Zhang, J., Zhang, Y. & Wang, C. (2018). Dynamics of paramagnetic and ferromagnetic ellipsoidal particles in shear flow under a uniform magnetic field. Physical Review Fluids, 3, 084201. (IF: 2.021) https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.3.084201

We theoretically and numerically study the effects of a uniform magnetic field on the dynamics of ellipsoidal ferromagnetic and paramagnetic particles in a simple shear flow at low Reynolds number. With numerical simulations we further illustrate their lateral migration in wall-bounded shear flows. Read paper

• Zhang, J., Sobecki, C., Zhang, Y., & Wang, C. (2018). Numerical investigation of dynamics of elliptical magnetic microparticles in shear flows. Microfluidics and Nanofluidics, 22(8), 83. (IF: 2.384) https://link.springer.com/article/10.1007/s10404-018-2103-z

We study the rotational dynamics of magnetic prolate elliptical particles in a simple shear flow subjected to a uniform magnetic field, using direct numerical simulations based on the finite element method. Read paper

• Zhang, J. & Wang, C. (2018). Numerical Study of Lateral Migration of Elliptical Magnetic Microparticles in Microchannels in Uniform Magnetic Fields. Magnetochemistry, 4(1), 16. (IF: N.A.) http://www.mdpi.com/2312-7481/4/1/16/htm

This work develops a direct numerical simulation (DNS) model to investigate the effects of strength and direction of the magnetic field, particle-wall separation distance and particle shape on the lateral migration in a plane Poiseuille flow under a uniform magnetic field. Read paper

2017

• Zhou, R., Sobecki, C. A., Zhang, J., Zhang, Y., & Wang, C. (2017). Magnetic control of lateral migration of ellipsoidal microparticles in microscale flows. Physical Review Applied, 8(2), 24019. (IF: 4.808) https://doi.org/10.1103/PhysRevApplied.8.024019

This study demonstrates a simple, effective and tunable technique to control the lateral migration of ellipsoidal micro-particles by combining micro-hydrodynamic flows with a uniform magnetic field. By adjusting the direction of the magnetic field, we can control the direction of the particle's lateral migration. Read paper

• Rallabandi, B., Wang, C., & Hilgenfeldt, S. (2017). Analysis of optimal mixing in open-flow mixers with time-modulated vortex arrays. Physical Review Fluids, 2(6), 64501. https://doi.org/10.1103/PhysRevFluids.2.064501

An Eulerian approach to optimize open-flow mixing with duty-cycled vortical crossflows is developed using general physical principles. For mixers based on microbubble streaming, the formalism identifies optimum mixing protocols that agree with experiments and numerical simulations of mixing. Read paper

• Bai, F., He, X., Yang, X., Zhou, R., & Wang, C. (2017). Three dimensional phase-field investigation of droplet formation in microfluidic flow focusing devices with experimental validation. International Journal of Multiphase Flow, 93, 130–141. (IF: 2.509) https://doi.org/10.1016/j.ijmultiphaseflow.2017.04.008 Read paper

Three-dimensional phase field simulations based on the finite element method are used to study droplet formation process at a low capillary number in a flow focusing micro-channel.

• Zhou, R., Bai, F., & Wang, C. (2017). Magnetic separation of microparticles by shape. Lab on a Chip, 17(3), 401–406. (IF: 6.045) https://doi.org/10.1039/C6LC01382A Read paper

Highlight: We demonstrate a novel technique of separating microparticles by shape with a uniform magnetic field. The magnetic torque breaks the rotational symmetry of the particle and causes shape-dependent migration.

2016

• Zhou, R., & Wang, C. (2016). Multiphase ferrofluid flows for micro-particle focusing and separation. Biomicrofluidics, 10(3), 34101. (IF: 2.535) https://doi.org/10.1063/1.4948656 Read paper

We demonstrate a novel strategy for focusing and separating diamagnetic micro-particles by using the laminar fluid interface of two co-flowing fluids - a ferrofluid and a non-magnetic fluid.

• Zhou, R., Yang, Q., Bai, F., Werner, J. A., Shi, H., Ma, Y., & Wang, C. (2016). Fabrication and integration of microscale permanent magnets for particle separation in microfluidics. Microfluidics and Nanofluidics, 20(7), 110. (IF: 2.344) https://doi.org/10.1007/s10404-016-1774-6 Read paper

We propose and demonstrate a simple and low-cost technique to fabricate microscale permanent magnetic microstructures and integrate them into microfluidic devices. The microstructures were fabricated with a liquid mixture of neodymium powders and PDMS.

• Zhou, R., & Wang, C. (2016). Microfluidic separation of magnetic particles with soft magnetic microstructures. Microfluidics and Nanofluidics, 20(3), 1–11. (IF: 2.344) https://doi.org/10.1007/s10404-016-1714-5 Read paper

We propose and demonstrate a simple and low-cost method for fabricating microfluidic devices for enhanced separation of magnetic particles. The microfluidic devices integrate soft magnetic microstructures next to microfluidic channels, with a distance of tens of micrometers.

2015

• Zhou, R., & Wang, C. (2015). Acoustic bubble enhanced pinched flow fractionation for microparticle separation. Journal of Micromechanics and Microengineering, 25(8), 84005. (IF: 1.794) https://doi.org/10.1088/0960-1317/25/8/084005 Read paper

We use an acoustic micro-bubble to enhance pinched flow fractionation (PFF) devices for micro-particle separation. The proposed technique utilizes micro-bubble streaming flows to overcome the limitations of conventional PFF.

• Zhang, Z., Zhou, R., Brames, D. P., & Wang, C. (2015). A Low-Cost Fabrication System for Manufacturing Soft-Lithography Microfluidic Master Molds. Micro and Nanosystems, 7(April 2016), 4–12. https://doi.org/10.2174/1876402907666150403232231 Read paper

We develop a low-cost and high-resolution micro-fabrication system that enables quick and inexpensive manufacturing of master molds for fabricating microfluidic devices via soft lithography.

• Marin, A., Rossi, M., Rallabandi, B., Wang, C., Hilgenfeldt, S., & Kähler, C. J. (2015). Three-Dimensional Phenomena in Microbubble Acoustic Streaming. Physical Review Applied, 3(4), 41001. (IF: 4.808) https://doi.org/10.1103/PhysRevApplied.3.041001 Read paper

Using astigmatism particle-tracking velocimetry, we reveal that the apparent planar streamlines, due to acoustic micro-bubble streaming, are actually projections of a stream surface with a pseudotoroidal shape. In such flows, microparticle trajectories present a much richer behavior, and have strong out-of-plane dynamics in regions close to the microbubble interface.

2014

• Rallabandi, B., Wang, C., & Hilgenfeldt, S. (2014). Two-dimensional streaming flows driven by sessile semicylindrical microbubbles. Journal of Fluid Mechanics, 739(January), 57–71. (IF: 2.821) https://doi.org/10.1017/jfm.2013.616 Read paper

A complete asymptotic theory of acoustic microbubble streaming flows is developed, requiring only the oscillatory driving frequency and material parameters as input, and properly accounting for bubble and wall boundary conditions.