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A new architecture of organic memristive device is proposed with a double-layered polyelectrolyte, one of which is a biological system that alone drives the memristive behavior. In the device the Physarum polycephalum was used as living organism, the polyaniline as conducting polymer for the source-drain channel. The key choice for the device functioning was the interposition of a biocompatible solid layer between polyaniline and living organism, that must result both electrochemically inert and able to preserve a good electrical conductivity of the polyaniline, notwithstanding the alkaline pH environment required for the surviving of living being, by avoiding strong acids. Pectin with a high degree of methylation and chitosan were tested as interlayer, but only the first one satisfied the essential requirements. Itwas demonstrated that only when the living organism was integrated in the device, the current-voltage characteristics showed the hysteretic rectifying trends typical of the memristive devices, which however disappeared if the Physarum polycephalum switched to its sclerotic state. The mould resulted to survive a series of at least three cycles of voltage-current measurements carried out in sequence. [ABSTRACT FROM AUTHOR]

Organic memristive device is an electronic system mimicking some properties of biological synapses. Slime mold - Physarum polycephalum - is a single cell living being, widely considered now for the unconventional computing application. This work is dedicated to the realization of hybrid organic memristive device/Physarum polycephalum system and studying of its electrical properties. It was found that the slime mold remains alive only when the appropriate biocompatible layer is inserted into the structure and that the characteristics of the system are very different from those of the standard organic memristive devices. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

The present work is dedicated to the use of Physarum polycephalum slime mold, an unicellular organism self-adapting, self-repairing and self-repellent, for the realization of elements for unconventional computational systems. Physarum continuously changes its shape under the influence of different stimuli like attractors (food in the most of cases) and repellents (light, temperature, humidity, chemicals), creating optimized networks. Here we introduced a new, softer, element able to influence the motion and the shape of Physarum: the DEFLECTOR. Physarum polycephalum, loaded with magnetic particles and placed under a magnetic field, is conditioned in its active zones routing and shape topology networks. Thus, slime mold can be used as particles carrier and, moreover, it is possible to deflect the mold movement and realize chemical composites in defined places what allows to consider Physarum as a simple version of bio-robot. On the other hand, we have realized the idea of creating networks with the varied conductivity with the slime mold on polyaniline (PANI) substrates. As the result, it was shown that Physarum growth results in the changing of the conductivity state of PANI layers in different ways, providing negative and positive patterning of the sample. The possibility to control mold's direction with a deflector together with the capability of Physarum to pattern PANI surfaces are the main points of this work. This paper opens new possibilities of the development in many fields and areas from the electrical circuit design and the bio-actuators (bio-) robot research, up to the unconventional computing and realization of a novel category of polymer-mold-modified. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Asymmetric electrical contact (gold and indium) was performed to the slime mold. Electrical characterization of such structure revealed rectifying behavior due to the Schottky effect and a hysteresis due to the electrochemical activity within the slime mold. [ABSTRACT FROM AUTHOR]

Slime mold Physarum polycephalum is a single cell visible by an unaided eye. The slime mold optimizes its network of protoplasmic tubes to minimize expose to repellents and maximize expose to attractants and to make efficient transportation of nutrients. These properties of P. polycephalum, together with simplicity of its handling and culturing, make it a priceless substrate for designing novel sensing, computing and actuating architectures in living amorphous biological substrate. We demonstrate that, by loading Physarum with magnetic particles and positioning it in a magnetic field, we can, in principle, impose analog control procedures to precisely route active growing zones of slime mold and shape topology of its protoplasmic networks.