title: Understanding Networks of Computing Chemical Droplet Neurons Based on Information Flow.
abstract: In this paper, we present general methods that can be used to explore the information processing potential of a medium composed of oscillating (self-exciting) droplets. Networks of Belousov-Zhabotinsky (BZ) droplets seem especially interesting as chemical reaction-diffusion computers because their time evolution is qualitatively similar to neural network activity. Moreover, such networks can be self-generated in microfluidic reactors. However, it is hard to track and to understand the function performed by a medium composed of droplets due to its complex dynamics. Corresponding to recurrent neural networks, the flow of excitations in a network of droplets is not limited to a single direction and spreads throughout the whole medium. In this work, we analyze the operation performed by droplet systems by monitoring the information flow. This is achieved by measuring mutual information and time delayed mutual information of the discretized time evolution of individual droplets. To link the model with reality, we use experimental results to estimate the parameters of droplet interactions. We exemplarily investigate an evolutionary generated droplet structure that operates as a NOR gate. The presented methods can be applied to networks composed of at least hundreds of droplets.
authors.affiliation: Friedrich Schiller University Jena, Department of Computer Science, Bio Systems Analysis Group, Ernst-Abbe-Platz 2, D-07743 Jena, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Gruenert
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Konrad
authors.initials: K
authors.lastname: Gizynski
authors.affiliation: Friedrich Schiller University Jena, Department of Computer Science, Bio Systems Analysis Group, Ernst-Abbe-Platz 2, D-07743 Jena, Germany.
authors.forename: Gabi
authors.initials: G
authors.lastname: Escuela
authors.affiliation: Al-Qunfudah Center for Scientific Research (QCSR), Umm Al-Qura University, 1109 Makkah Al-Mukarramah, Kingdom of Saudi Arabia.|Friedrich Schiller University Jena, Department of Computer Science, Bio Systems Analysis Group, Ernst-Abbe-Platz 2, D-07743 Jena, Germany.
authors.forename: Bashar
authors.initials: B
authors.lastname: Ibrahim
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Gorecki
authors.affiliation: Friedrich Schiller University Jena, Department of Computer Science, Bio Systems Analysis Group, Ernst-Abbe-Platz 2, D-07743 Jena, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Dittrich
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004058:Diffusion; D019277:Entropy; D007257:Information Theory; D016014:Linear Models; D044085:Microfluidics; D016571:Neural Networks, Computer; D010507:Periodicity; D014741:Video Recording
keywords: Artificial neural networks; biomimetics; chemical computing; information theory; molecular computing; synthetic biology; unconventional computing