Expert has focused on minimizing the current needed to yield lift/stabilization forces with high speed magnetic bearings. He uses boundary element field analyses to perform this optimization as well as to get leakage and eddy current losses. He is developing a passive bearing using null-flux coils.
Expert finds boundary element modeling an excellent technique for accurately modeling electric and magnetic fields. He is capable of extremely accurate predictions of global quantities such as force, torque, inductance, and capacitance. Using boundary element modeling, Expert has been able to analyze literally hundreds of configurations in short order.
Nearly all of Expert's career has centered on the use of numerical modeling systems. A good numerical model can save endless hours in the laboratory or machine shop. Much of his modeling is now performed using MATLAB. At Georgia Tech he teaches a graduate course which focuses on partial differential equations, eigenvalue analyses, optimization and neural net techniques.
Expert has specialized in an area of electromagnetics known as quasistatics, where the displacement current is negligible. His doctorate was in continuum electromechanics - the science of how fields and fluids interact with matter. This area includes eddy currents, electromechanics, electroosmosis, plasma dynamics, and field-fluid pumping.
The operation of many electromechanical devices is summarized by knowing the mutual coupling of coils in various positions. The ability to determine how inductance changes is also essential to many magnetic based sensors. Expert has performed hundreds of analyses on electromechanical devices using inductive coupling.
Expert has centered the last twelve years of his career largely on problems where currents are induced by changing magnetic fields. These applications have ranged from non-destructive evaluation, to sensing, fusion, nerve stimulation, new computational techniques, and stable levitation.
Sensitive electrical impedance measurements can be performed to predict the composition of the interior of the body. Expert is working on techniques to solve the 'inverse problem' associated with such applications.
Having a background in both electrical field theory and fluid mechanics allows Expert to analyze how fields can be used to manipulate fluids. Examples include the shaping of fluids (e.g. with contact lens, menisci) and passive levitation using a conducting fluid in a time-varying magnetic field.
Expert notes that stable magnetic levitation can be realized effectively by using eddy current forces which come as a result of passive induction. By using null-flux coils, stable levitation both for rotary and linear applications can be produced. The same levitation effects are useful in metal molding and fabrication. Expert has two patents pending in the field of magnetic levitation.
Non-invasive nerve stimulation is effectively produced using rapidly-changing magnetic fields. The changing magnetic field induces an electric field causing charge transfer to occur across the nerve membrane interface causing the nerve to fire. The source of the field can be either external or internal to the body. Expert has constructed successful stimulators (in vitro and in vivo) and has written several papers on these devices.