Excitability Modulation of Oscillating Media in
3D-Printed Structures
Artificial Life, 21 (2):
225--233 (May 2015)DOI: 10.1162/artl_a_00158
Abstract
Excitation and oscillation are central to living
systems. For excitable systems, which can be brought
into oscillation by an external stimulus, the
excitation threshold is a crucial parameter. This is
evident for neurons, which only generate an action
potential when exposed to a sufficiently high
concentration of excitatory neurotransmitters, which
may only be achieved when multiple presynaptic axons
deliver their action potential simultaneously to the
synaptic cleft. Dynamic systems composed of relatively
simple chemicals are of interest because they can serve
as a model for physiological processes or can be
exploited to implement chemical computing. With these
applications in mind, we have studied the properties of
the oscillatory Belousov-Zhabotinsky (BZ) reaction in
3D-printed reaction vessels with open channels of
different dimensions. It is demonstrated that the
channel geometry can be used to modulate the
excitability of the BZ medium, switching a continuously
oscillating medium to an excitable medium. Because
large networks of channel-connected reaction wells of
different depth can easily be fabricated by 3D
printing, local excitability modulation could be built
into the structure of the reaction vessel itself,
opening the way to more extensive experimentation with
networks of chemical oscillators.
