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Selected Works

Professor Weihua Li

For

Articles 1 - 3 of 3

Full-Text Articles in Engineering

A 3-D Microelectrode System For Dielectrophoretic Manipulation Of Microparticles, Dafeng Chen, Hejun Du, Haiqing Gong, Weihua Li Aug 2012

A 3-D Microelectrode System For Dielectrophoretic Manipulation Of Microparticles, Dafeng Chen, Hejun Du, Haiqing Gong, Weihua Li

Professor Weihua Li

This paper presents a microfluidic system for manipulation and separation of micron-sized particles based on the combined use of negative dielectrophoresis (DEP) and hydrodynamic forces. A 3-D microelectrode structure (so called paired electrode array) are constructed face to face on the top and bottom sides of the microchannel and driven with highfrequency AC voltage to generate dielectrophoretic gates. Depending on the relative strengths of the two forces, particles such as polystyrene beads or cells carrying by a laminar flow can either penetrate the gate or settle there. This gives rise to certain applications including selectively concentrating particles from the flow, …


A Variable Stiffness Mr Damper For Vibration Suppression, Xianzhou Zhang, Weihua Li, Yang Zhou Aug 2012

A Variable Stiffness Mr Damper For Vibration Suppression, Xianzhou Zhang, Weihua Li, Yang Zhou

Professor Weihua Li

This paper presents the development of a magnetorheological (MR) fluid-based variable stiffness damper and analysis its applications in vibration suppression. The MR fluid isolator used a MR valve control unit and bladders to achieve the variable stiffness and damping in stepless and relative large scope. A mathematical model of the isolator was derived, a prototype of the MR fluid isolator was fabricated and its dynamic behavior was measured in vibration under various applied magnetic fields. The effective stiffness and damping coefficients of the isolator under various magnetic fields were identified and the dynamic performances of isolator were evaluated with simulation. …


A 3-D Microelectrode System For Dielectrophoretic Manipulation Of Microparticles, Dafeng Chen, Hejun Du, Haiqing Gong, Weihua Li Aug 2012

A 3-D Microelectrode System For Dielectrophoretic Manipulation Of Microparticles, Dafeng Chen, Hejun Du, Haiqing Gong, Weihua Li

Professor Weihua Li

This paper presents a microfluidic system for manipulation and separation of micron-sized particles based on the combined use of negative dielectrophoresis (DEP) and hydrodynamic forces. A 3-D microelectrode structure (so called paired electrode array) are constructed face to face on the top and bottom sides of the microchannel and driven with highfrequency AC voltage to generate dielectrophoretic gates. Depending on the relative strengths of the two forces, particles such as polystyrene beads or cells carrying by a laminar flow can either penetrate the gate or settle there. This gives rise to certain applications including selectively concentrating particles from the flow, …