(7ht) Computational Micro/Nanofluidics

I am interested in understanding transport phenomena in fluid medium at micro/nanoscales using high-performance computing. These transport phenomena have broad applications in energy storage, water/air purification, and particle/cell focusing and separation, just to name a few. The success of micro/nanofluidic devices hinges on the precise control of the fluid, ion, thermal, and particulate transport in these devices. The powerful codes I developed (http://miccomcodes.org) for simulations of particulates suspended in micro/nanosystems governed by electrostatic, magnetostatic, and hydrodynamic interactions open up numerous opportunities to explore and understand the fundamental physics of transport phenomena in micro/nanosystems for diverse applications.

Teaching Interests:

At both undergraduate and graduate level, I can teach any course in the transport phenomena and thermodynamics area. I can also develop graduate courses in extreme-scale scientific computing by leveraging my expertise in high-performance computing and scalable scientific software.

Successful Proposals:

Length-scale bridging computational scheme for structure and transport, assisted writing annual renewal proposal for postdoctoral supervisor Dr. Olle G. Heinonen

Postdoctoral Projects:

Length-scale bridging computational scheme for structure and transport, under the supervision of Dr. Olle G. Heinonen at the Materials Science Division, Argonne National Laboratory

Continuum-Particle Simulation Software in Midwest Integrated Center for Computational Materials, under the supervision of Prof. Juan J. de Pablo at the Institute for Molecular Engineering, University of Chicago

PhD Dissertation:

Nonequilibrium Transport of Ionic Liquids in Electrified Nanosystems, under the supervision of Prof. Rui Qiao at the Department of Mechanical Engineering, Virginia Tech

Research Experience:

My academic career has been focused on developing and utilizing high-performance computer simulations, that span multiple length scales (nanometer to micrometer) and time scales (picosecond to second), for scientific research in the forefront of multiple physical domains (electrostatics, magnetostatics, hydrodynamics, ion transport, to name a few). I have developed powerful mesoscale computational tools for computing electrostatic/magnetostatic interactions between arbitrary-shaped particles, and for modeling Brownian dynamics of hydrodynamically interacting objects in general geometries. I have made the code publicly available through the http://miccomcodes.org site. I have also discovered novel transport of ionic liquids in electrified nanosystems using molecular and continuum simulations, which laid important theoretical foundations for improving the performance of supercapacitors.

Teaching Experience:

Aside from my academic research, I have spent two semesters teaching lectures and experiments for an undergraduate core course “Mechanical Engineering Laboratory” in the Department of Mechanical Engineering at Clemson University. I have also mentored graduate students and am the “Go-to Expert” on using scalable libraries and high-performance computational tools in research groups at Argonne National Laboratory and The University of Chicago.

Future Direction:

The short-term research projects that I will pursue focus on exploring and understanding task-oriented manipulation of suspended objects, such as macromolecules and colloidal particles, in microfluidic systems and ion transport of novel electrolytes, such as novel polyelectrolytes and ionic liquids, in nanofluidic systems. The long-term research that I will pursue aims to explore and obtain an integrated understanding, in close collaborations with experimentalists, of thermal, ion, and mass transport in biological systems (e.g., blood vessels), energy systems (e.g., supercapacitors) and mechanical systems (e.g., magnetorheological/electrorheological devices). The outcomes of my research are the better understanding and new insights for designing advanced technologies for water/air purification, macromolecule manipulation and sequencing, and energy storage/transport. In the ultimate level, my research could help address critical demands for clean environment and energy, and benefit human health.

Selected Publications:

Xujun Zhao^†, Jiyuan Li^†, Xikai Jiang^†, Dmitry Karpeev, Olle Heinonen, Barry Smith, Juan P. Hernandez-Ortiz, Juan J. de Pablo, Parallel O(N) Stokes’ solver towards scalable Brownian dynamics of hydrodynamically interacting objects in general geometries, J. Chem. Phys., 146, 244114, 2017 (†: the authors contributed equally)

Xikai Jiang, Jiyuan Li, Xujun Zhao, Jian Qin, Dmitry Karpeev, Juan Hernandez-Ortiz, Juan J. de Pablo, and Olle Heinonen, An O(N) and parallel approach to integral problems by a kernel-independent fast multipole method: Application to polarization and magnetization of interacting particles, J. Chem. Phys., 145, 064307, 2016

Xikai Jiang, Ying Liu, and Rui Qiao, Current rectification for transport of room-temperature ionic liquids through conical nanopores, J. Phys. Chem. C, 120 (8), 4629-4637, 2016

Guang Feng, Xikai Jiang, Rui Qiao, and Alexei Kornyshev, Water in ionic liquids at electrified interfaces: the anatomy of electrosorption, ACS Nano, 8 (11) 11685-11694, 2014

Xikai Jiang, Jingsong Huang, Hui Zhao, Bobby Sumpter, and Rui Qiao, Dynamics of electrical double layer formation in room-temperature ionic liquids under constant-current charging conditions, J. Phys. Condens. Matter, 26 (28), 284109, 2014

Xikai Jiang, Jingsong Huang, Bobby Sumpter, and Rui Qiao, Electro-induced dewetting and concomitant ionic current avalanche in nanopores, J. Phys. Chem. Lett., 4 (18), 3120-3126, 2013

Xikai Jiang, and Rui Qiao, Electrokinetic transport in room-temperature ionic liquids: amplification by short-wavelength hydrodynamics, J. Phys. Chem. C, 116 (1), 1133-1138, 2012