Istvan Z. Kiss, Ph.D.

Istvan Z. Kiss
Assistant Professor
Department of Chemistry
Saint Louis University

Abstract:

Complex chemical and biological systems exhibit dynamic self-organization with emergent properties depending both on the behavior of the constituent parts and the types and extent of their interactions. We introduce the subject of chemical complexity through the description of macroscale and microscale electrochemical oscillations that occur on multi-particle electrodes.

In the presentation, electrochemical oscillations are described by using the concept of cycle phase and determine how the frequency and precision of the current oscillations on a single electrode depends on resistance and temperature, and how the extent of interactions affects periodic and chaotic synchronization patterns on electrode arrays.

For optimal pacemaker design, a theory for obtaining waveform for the effective entrainment of a weakly forced oscillator is presented. Phase model analysis is combined with calculus of variation to derive a waveform with which entrainment of an oscillator is achieved with minimum power forcing. The theory is tested in chemical entrainment experiments in which oscillations close to and further away from a Hopf bifurcation exhibited sinusoidal and higher harmonic nontrivial optimal waveforms, respectively.