Electric-field-controlled unpinning of scroll waves

Area of Science:

• Chemical kinetics
• Complex systems dynamics
• Nonlinear phenomena

Background:

• Three-dimensional excitation vortices are observed in diverse systems, including chemical reactions and cardiac tissue.
• The dynamics of these vortices are significantly influenced by pinning to unexcitable heterogeneities.
• Understanding vortex-heterogeneity interactions is crucial for controlling complex spatiotemporal patterns.

Purpose of the Study:

• To experimentally demonstrate the unpinning of excitation vortices from obstacles.
• To investigate the role of external electric fields in controlling vortex dynamics.
• To validate experimental findings with numerical simulations.

Main Methods:

• Utilized the Belousov-Zhabotinsky reaction as an experimental model system.
• Employed inert and impermeable spheres as pinning heterogeneities.
• Applied external electric fields to induce vortex unpinning.
• Conducted numerical simulations of a reaction-diffusion-advection model.

Main Results:

• Successfully demonstrated vortex unpinning from a pair of spheres using electric fields.
• Observed a slow reorientation and deformation preceding abrupt unpinning.
• Experimental results were accurately reproduced by numerical simulations.
• Showcased the ability to control vortex behavior via external stimuli.

Conclusions:

• External electric fields provide an effective method for unpinning excitation vortices from obstacles.
• Vortex unpinning involves a complex interplay of reorientation, deformation, and abrupt release.
• The reaction-diffusion-advection model accurately captures the observed phenomena, validating the underlying physics.