arXiv subjects

Alessandro Chiolerio

Publications and source records attributed to Alessandro Chiolerio.

18 recordsLinked to original sources

arXiv2024

Complexity and nonlinearity of colloid electrical transducers

This work explores the complexity and nonlinearity of seven different colloidal suspensions-Au, ferrofluid, TiO2}, ZnO, g-C3N4, MXene, and PEDOT:PSS-when electrically stimulated with fractal, chaotic, and random binary signals. The recorded electrical responses were analyzed using entropy, file compression, fractal dimension, and Fisher information measures to quantify complexity. The nonlinearity introduced by each colloid was evaluated by the deviation of the output from the best-fit hyperplane of the input-output mapping. The results showed that TiO2 was the most complex colloid across all inputs, exhibiting high entropy, poor compressibility, and an unpredictable response pattern. The colloids also exhibited significant nonlinearity, making them promising candidates for reservoir computation, where the mapping of inputs into high-dimensional nonlinear states is advantageous. This study provides insight into the dynamics of colloids and their potential for unconventional computational applications that exploit their inherent complexity and nonlinearity, and it provides a rapid method for assessing the suitability of a particular material for use as a computational substrate before others.

cond-mat.soft↗

arXiv2024

On complexity of colloid cellular automata

The colloid cellular automata do not imitate the physical structure of colloids but are governed by logical functions derived from the colloids. We analyse the space-time complexity of Boolean circuits derived from the electrical responses of colloids: ZnO (zinc oxide, an inorganic compound also known as calamine or zinc white, which naturally occurs as the mineral zincite), proteinoids (microspheres and crystals of thermal abiotic proteins), and combinations thereof to electrical stimulation. To extract Boolean circuits from colloids, we send all possible configurations of two-, four-, and eight-bit binary strings, encoded as electrical potential values, to the colloids, record their responses, and thereby infer the Boolean functions they implement. We map the discovered functions onto the cell-state transition rules of cellular automata (arrays of binary state machines that update their states synchronously according to the same rule) -- the colloid cellular automata. We then analyse the phenomenology of the space-time configurations of the automata and evaluate their complexity using measures such as compressibility, Shannon entropy, Simpson diversity, and expressivity. A hierarchy of phenomenological and measurable space-time complexity is constructed.

nlin.CG↗

arXiv2023

Reservoir Computing with Colloidal Mixtures of ZnO and Proteinoids

Liquid computers use incompressible fluids for computational processes. Here we present experimental laboratory prototypes of liquid computers using colloids composed of zinc oxide (ZnO) nanoparticles and microspheres containing thermal proteins (proteinoids). The choice of proteinoids is based on their distinctive neuron-like electrical behaviour and their similarity to protocells. In addition, ZnO nanoparticles are chosen for their non-trivial electrical properties. Our research demonstrates the successful extraction of 2-, 4- and 8-bit logic functions in ZnO proteinoid colloids. Our analysis shows that each material has a distinct set of logic functions, and that the complexity of the expressions is directly related to each material present in a mixture. These findings provide a basis for the development of future hybris liquid devices capable of general purpose computing.

cs.ET↗

arXiv2023

Logical circuits in colloids

Colloid-based computing devices offer remarkable fault tolerance and adaptability to varying environmental conditions due to their amorphous structure. An intriguing observation is that a colloidal suspension of ZnO nanoparticles in DMSO exhibits reconfiguration when exposed to electrical stimulation and produces spikes of electrical potential in response. This study presents a novel laboratory prototype of a ZnO colloidal computer, showcasing its capability to implement various Boolean functions featuring two, four, and eight inputs. During our experiments, we input binary strings into the colloid mixture, where a logical ``True" state is represented by an impulse of an electrical potential. In contrast, the absence of the electrical impulse denotes a logical ``False" state. The electrical responses of the colloid mixture are recorded, allowing us to extract truth tables from the recordings. Through this methodological approach, we demonstrate the successful implementation of a wide range of logical functions using colloidal mixtures. We provide detailed distributions of the logical functions discovered and offer speculation on the potential impacts of our findings on future and emerging unconventional computing technologies. This research highlights the exciting possibilities of colloid-based computing and paves the way for further advancements.

cs.ET↗

arXiv2023

Kombucha electronics

A kombucha is a tea and sugar fermented by over sixty kinds of yeasts and bacteria. This symbiotic community produces kombucha mats, which are cellulose-based hydrogels. The kombucha mats can be used as an alternative to animal leather in industry and fashion once they have been dried and cured. Prior to this study, we demonstrated that living kombucha mats display dynamic electrical activity and distinct stimulating responses. For use in organic textiles, cured mats of kombucha are inert. To make kombucha wearables functional, it is necessary to incorporate electrical circuits. We demonstrate that creating electrical conductors on kombucha mats is possible. After repeated bending and stretching, the circuits maintain their functionality. In addition, the abilities and electronic properties of the proposed kombucha, such as being lighter, less expensive, and more flexible than conventional electronic systems, pave the way for their use in a diverse range of applications.

cs.ET↗

arXiv2022

Evidence of In-Memory Computing in a Ferrofluid

Magnetic fluids are excellent candidates for important research fields including energy harvesting, biomedical applications, soft robotics and exploration. However, notwithstanding relevant advancements such as shape reconfigurability, that have been demonstrated, there is no evidence for their computation capability, including the emulation of synaptic functions. Here, we experimentally demonstrate that a Fe3O4 water-based Ferrofluid (FF) can perform electrical analog computing and be programmed using quasi DC signals and read at Radio Frequency (RF) mode. We have observed features in all respects attributable to a memristive behavior, featuring both short and long-term information storage capacity and plasticity. The colloid was capable of classifying digits of a 8x8 pixel dataset using a custom in-memory signal processing scheme, and through Physical Reservoir Computing (PRC) by training a readout layer.

cs.ET↗

arXiv2022

Pavlovian reflex in colloids

Pavlovian reflex is an essential mechanism of nervous systems of living beings which allows them to learn. Liquid colloid computing devices offer a high degree of fault-tolerance, reconfigurability and plasticity. As a first step towards designing and prototyping colloidal neuromorphic computing systems we decided to evaluate if it is possible to implement Pavlovian reflexes. We equate an increase of a synaptic weight with decreased resistance. In laboratory experiments we demonstrated that it is possible to implement Pavlovian learning using just two volumes of colloid liquid.

cs.ET↗

arXiv2022

Electrical frequency discrimination by fungi Pleurotus ostreatus

We stimulate mycelian networks of oyster fungi Pleurotus ostreatus with low frequency sinusoidal electrical signals. We demonstrate that the fungal networks can discriminate between frequencies in a fuzzy or threshold based manner. Details about the mixing of frequencies by the mycelium networks are provided. The results advance the novel field of fungal electronics and pave ground for the design of living, fully recyclable, electron devices.

cs.ET↗

arXiv2022

Tests on High-Directivity Unconventional Biconical Type Antennas

Biconical-type antennas featuring high directivity have been designed, created, and tested in anechoic chamber. Results in the range between 1 and 5 GHz are presented in this article. In particular, two different configurations have been tested, with and without dielectric lenses, both involving rapid prototyping tools (3D printing) for the dielectric and the antenna support. A very high directivity is nowadays demanded by efficient and sustainable point-to-point communications or energy transfer protocols, to avoid releasing energy in neighboring areas and preserve data transfer security. As demonstrated here, special biconical type antennas featuring a 3D printed polylactic acid (PLA) dielectric lens can achieve a good directivity, with a corresponding emission lobe centered around 8.4 degrees, featuring a FWHM of 6.4 degrees. Dielectric lens-free antennas, featuring an unconventional shape, can also achieve a good directivity, with a corresponding emission lobe centered around 10.0 degrees, featuring a FWHM of 14.2 degrees. The preliminary results shown here explore some of the aspects of the vast configuration space (which include fabrication techniques, dielectric materials, conductive supports, etc.) and open the route for further optimization studies. The aim would be to adjust the various degrees of freedom in order to achieve what can be defined as "infinite" directivity.

physics.app-ph↗

arXiv2021

Fungal electronics

Fungal electronics is a family of living electronic devices made of mycelium bound composites or pure mycelium. Fungal electronic devices are capable of changing their impedance and generating spikes of electrical potential in response to external control parameters. Fungal electronics can be embedded into fungal materials and wearables or used as stand alone sensing and computing devices.

cs.ET↗

arXiv2021

On stimulating fungi $Pleurotus~ostreatus$ with Cortisol

Fungi cells are capable of sensing extracellular cues through reception, transduction and response systems which allow them to communicate with their host and adapt to their environment. They display effective regulatory protein expressions which enhance and regulate their response and adaptation to a variety of triggers such as stress, hormones, light, chemicals and host factors. In our recent studies, we have shown that $Pleurotus$ oyster fungi generate electrical potential impulses in the form of spike events as a result of their exposure to environmental, mechanical and chemical triggers, demonstrating that it is possible to discern the nature of stimuli from the fungi electrical responses. Harnessing the power of fungi sensing and intelligent capabilities, we explored the communication protocols of fungi as reporters of human chemical secretions such as hormones, addressing the question if fungi can sense human signals. We exposed $Pleurotus$ oyster fungi to cortisol, directly applied to a surface of a hemp shavings substrate colonised by fungi, and recorded the electrical activity of fungi. The response of fungi to cortisol was also supplementary studied through the application of X-ray to identify changes in the fungi tissue, where receiving cortisol by the substrate can inhibit the flow of calcium and, in turn, reduce its physiological changes. This study could pave the way for future research on adaptive fungal wearables capable for detecting physiological states of humans and biosensors made of living fungi.

cs.ET↗

arXiv2020

Reactive fungal wearable

Smart wearables sense and process information from the user's body and environment and report results of their analysis as electrical signals. Conventional electronic sensors and controllers are commonly, sometimes augmented by recent advances in soft electronics. Organic electronics and bioelectronics, especially with living substrates, offer a great opportunity to incorporate parallel sensing and information processing capabilities of natural systems into future and emerging wearables. Nowadays fungi are emerging as a promising candidate to produce sustainable textiles to be used as ecofriendly biowearables. To assess the sensing potential of fungal wearables we undertook laboratory experiments on electrical response of a hemp fabric colonised by oyster fungi~\emph{Pleurotus ostreatus} to mechanical stretching and stimulation with attractants and repellents. We have shown that it is possible to discern a nature of stimuli from the fungi electrical responses. The results paved a way towards future design of intelligent sensing patches to be used in reactive fungal wearables.

cs.ET↗

arXiv2020

On resistive spiking of fungi

We study long-term electrical resistance dynamics in mycelium and fruit bodies of oyster fungi P. ostreatus. A nearly homogeneous sheet of mycelium on the surface of a growth substrate exhibits trains of resistance spikes. The average width of spikes is c.~23~min and the average amplitude is c.~1~kOhm. The distance between neighbouring spikes in a train of spikes is c.~30~min. Typically there are 4-6 spikes in a train of spikes. Two types of resistance spikes trains are found in fruit bodies: low frequency and high amplitude (28~min spike width, 1.6~kOhm amplitude, 57~min distance between spikes) and high frequency and low amplitude (10~min width, 0.6~kOhm amplitude, 44~min distance between spikes). The findings could be applied in monitoring of physiological states of fungi and future development of living electronic devices and sensors.

cs.ET↗

arXiv2020

Fungal sensing skin

A fungal skin is a thin flexible sheet of a living homogeneous mycelium made by a filamentous fungus. The skin could be used in future living architectures of adaptive buildings and as a sensing living skin for soft self-growing/adaptive robots. In experimental laboratory studies we demonstrate that the fungal skin is capable for recognising mechanical and optical stimulation. The skin reacts differently to loading of a weight, removal of the weight, and switching illumination on and off. These are the first experimental evidences that fungal materials can be used not only as mechanical `skeletons' in architecture and robotics but also as intelligent skins capable for recognition of external stimuli and sensorial fusion.

cs.ET↗

arXiv2020

Tactile sensing and computing on a random network of conducting fluid channels

Liquid electronic sensors are typically based on regular arrays of channels filled with a conductive liquid. We propose that a random planar network of conducting liquid allows us for a wider spectrum of electrical responses and localisation of tactile stimuli. We also speculate that a computation protocol can be implemented on such a network, featuring mechanical inputs and electrical outputs. Our results pave a way towards future developments on sensing and computing wearables with disordered sensing networks structure.

cs.ET↗

arXiv2019

Liquid metal solves maze

A room temperature liquid metal features a melting point around room temperature. We use liquid metal gallium due to its non-toxicity. A physical maze is a connected set of Euclidean domains separated by impassable walls. We demonstrate that a maze filled with sodium hydroxide solution is solved by a gallium droplet when direct current is applied between start and destination loci. During the maze solving the droplet stays compact due to its large surface tension, navigates along lines of the highest electrical current density due its high electrical conductivity, and goes around corners of the maze's corridors due to its high conformability. The droplet maze solver has a long life-time due to the negligible vapour tension of liquid gallium and its corrosion resistance and its operation enables computational schemes based on liquid state devices.

cs.ET↗

arXiv2019

On resistance switching and oscillations in tubulin microtubule droplets

We study electrical properties of Taxol-stabilised microtubule (MT) ensembles in a droplet of water. We demonstrate that the MT droplets act as electrical switches. Also, a stimulation of a MT droplet with a positive fast impulse causes oscillation of the droplet's resistance. The findings will pave a way towards future designs of MT-based sensing and computing devices, including data storage and featuring liquid state.

cs.ET↗

arXiv2019

The pH sensitivity of solvated tectomer electronics

Colloidal liquid robotics with embodied intelligence solutions mimicking biologic systems, in response to the future increasingly distributed sensing and the resulting data to be managed, has been proposed as the next cybernetic paradigm. Solutions for data storage and readout in liquido require a physical structure able to change configuration under electrical stimuli. We propose tectomers as a candidate for such an adaptive structure. A tectomer is a oligomer made of few oligoglycine units with a common centre. Tectomers undergo pH dependent assembly in a single layer supramers. Tectomers represent a stable paradigm, in their amorphous or crystalline forms, reversibly influenced by solution pH, whose electronic properties are studied herein.

cs.ET↗