Relevant publications:

Modeling Spiral Inductors in SOS Processes
Kuhn, W.B.; Xin He; Mojarradi M.
Electron Devices, IEEE Transactions on, Volume: 51, Issue: 5, May 2004

Spiral Inductor Performance in Deep-Submicron Bulk-CMOS with Copper Interconnects
Kuhn, W.B.; Orsborn, A.W.; Peterson, M.C.; Kythakyapuzha, S.R.; Hussein, A.I.; Jun Zhang; Jianming Li; Shumaker, E.A.; Nair, N.C.
Radio Frequency Integrated Circuits (RFIC) Symposium, 2002 IEEE , 2-4 June 2002

An Approach for the Calculation of Magnetic Field within Square Spiral Inductors at Low Frequency
N. M. Ibrahim, and W. B. Kuhn
International Journal of Numerical Modelling: Electronic Networks, Devices, and Fields, 15:339-354, 2002.

Analysis of Current Crowding Effects in Multiturn Spiral Inductors
Kuhn, W.B.; Ibrahim, N. M.
Microwave Theory and Techniques, IEEE Transactions on, Volume: 49, Issue: 1, Jan. 2001

Analytical Modeling of Current Crowding Effects in Multi-turn Spiral Inductors
Kuhn, W.B.; Ibrahim, N.M.
IEEE Transactions on Microwave Theory and Techniques, pp. 31-38, Jan. 2001



A large part of the research that has been carried out by the KSU Communications Research Lab has been focused on inductors.  Not inductors in general, but rather the performance and applications of spiral inductors fabricated in RFICs.  Publications related to spiral inductors can be found here.

One such publication was centered around the effects of current crowding in multi-turn spiral inductors within an IC.  Current crowding, among other things, is responisble for an inductor's increasing effective resistance with increasing signal frequency.  During the course of this project, data was taken to visually simulate how current "crowds" around these turns of metal.  Below are two animations showing current traveling through the fabricated inductor, for two inductors composed of metals of different thicknesses.  In both animations, the currents appear white in color.


And for an inductor fabricated with a thicker metal: