Artificial neurons with logical properties based on paired-band microelectrode assemblies

Electrochemically operated devices based on paired-band microelectrode asse mblies, which mimic the five basic physicochemical steps of neuronal proces sing of information (namely, propagation of electrical impulse along the em itting neuron to its synaptic cleft, release of chemical messenger in the s ynaptic cleft, diffusion of chemical messenger across the synaptic gap, det ection of chemical messenger by the receiving neuron, propagation of electr ical impulse along the receiving neuron), can be built by taking advantage of the unique properties of double-band electrodes. It is shown that such a rtificial neurons can be designed to perform as Boolean logical gates with AND or OR functionalities. The time responses of the devices and the basic theoretical features, which explain their unique properties, have been inve stigated analytically and through accurate conformal mapping simulations of the diffusional cross-talk operating in the vicinity of each coupled doubl e-band assembly. These simulations are in complete agreement with experimen tal observations. Furthermore they allow a simple analogy to be established between the device at hand and a simple double band. Based on this analogy , simple analytical formulations of the response time of the system and of the limiting currents that can pass through the assembly are proposed. The relevance of the present results to other situations in which analogous phy sico - chemical phenomena operate is also discussed.