Unconventional Computing Group

Bristol, United Kingdom

Unconventional Computing Group

Bristol, United Kingdom
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Gale E.,Unconventional Computing Group
Proceedings - UKSim-AMSS 16th International Conference on Computer Modelling and Simulation, UKSim 2014 | Year: 2014

The memristor, the recently discovered fundamental circuit element, is of great interest for neuromorphic computing, nonlinear electronics and computer memory. It is usually modelled either using Chua's equations, which lack material device properties, or using Strukov's phenomenological model (or models derived from it), which deviates from Chua's definitions due to the lack of a magnetic flux term. It is shown that by modelling the magnetostatics of the memory-holding ionic current (oxygen vacancies in the Strukov memristor), the memristor's magnetic flux can be identified as the flux arising from the ions. This leads to a novel theory of memristance consisting of two components: 1. A memory function which describes how the memristance, as felt by the ions, affects the conducting electrons located in the 'on' part of the device; 2. A conservation function which describes the time-varying resistance in the 'off' part of the device. This model allows for a straight-forward incorporation of the ions within the electronic theory and relates Chua's constitutive definition of a memristor with device material properties for the first time. © 2014 IEEE.


De Lacy Costello B.,Institute of biosensing technology | De Lacy Costello B.,Unconventional Computing Group | Jahan I.,Institute of biosensing technology | Jahan I.,Unconventional Computing Group | And 4 more authors.
International Journal of Unconventional Computing | Year: 2013

A gas free analogue of the Belousov-Zhabotinsky reaction catalysed by ferroin and encapsulated in phospholipid stabilised vesicles is reported. A reaction mixture which exhibits spontaneous oscillation and excitation transfer between vesicles was formulated. By adjusting the reagent concentrations a quiescent state with fewer spontaneous oscillations was achieved. Using relatively low power laser sources of specific wavelengths (green 532nm and blue 405nm) it was shown that waves could be reproducibly initiated within the BZ vesicles. Furthermore, despite the reduced excitability of the system overall the initiated waves exhibited vesicle to vesicle transfer. It was possible to manipulate single vesicles and design simple circuits based on a 2D validation of collision based circuits. Therefore, we conclude that this BZ system exhibits promise for computing applications based on 3D networks of vesicles. © 2013 Old City Publishing, Inc.

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