The Role of the Internal Capacitance in Organic Memristive Device for Neuromorphic and Sensing Applications

2021 ◽  
pp. 2100494
Author(s):  
Silvia Battistoni ◽  
Matteo Cocuzza ◽  
Simone Luigi Marasso ◽  
Alessio Verna ◽  
Victor Erokhin
Keyword(s):  
Memristive Device ◽  
Sensing Applications

The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh
Keyword(s):  
Biological Imaging ◽  
Ph Sensing ◽  
Hydrophobic Residue ◽  
Ideal Candidate ◽  
Self Assembling ◽  
Sensing Applications ◽  
Β Sheets ◽  
The Stability ◽  
Dynamics Simulations

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>

Local-Activity and Simultaneous Zero-Hopf Bifurcations Leading to Multistability in a Memristive Circuit

2021 ◽  
Vol 31 (15) ◽  
Author(s):  
Marcelo Messias ◽  
Alisson de Carvalho Reinol
Keyword(s):  
Hopf Bifurcations ◽  
Initial Condition ◽  
Parameter System ◽  
Memristive Device ◽  
Final State ◽  
State Variable ◽  
Stable Periodic ◽  
Memristive Circuit ◽  
Line Of Equilibria

In this paper, we consider a memristive circuit consisting of three elements: a passive linear inductor, a passive linear capacitor and an active memristive device. The circuit is described by a four-parameter system of ordinary differential equations. We study in detail the role of parameters in the dynamics of the system. Using the existence of first integrals, we show that the circuit may present a continuum of stable periodic orbits, which arise due to the occurrence of infinitely many simultaneous zero-Hopf bifurcations on a line of equilibria located in the region where the memristance is negative and, consequently, the memristive device is locally-active. These bifurcations lead to multistability, which is a difficult and interesting problem in applied models, since the final state of a solution depends crucially on its initial condition. We also study the control of multistability by varying a parameter related to the state variable of the memristive device. All analytical results obtained were corroborated by numerical simulations.

TiO2 Nanopowders for Sensing Applications; A Comparison between Traditional and Hydrothermal Synthesis Way

2006 ◽  
Vol 45 ◽  
pp. 205-208 ◽  
Author(s):  
Marco Nagliati ◽  
M.C. Carotta ◽  
S. Gherardi ◽  
Isidoro Giorgio Lesci ◽  
G. Martinelli
Keyword(s):  
Gas Sensing ◽  
Sol Gel ◽  
Spherical Shape ◽  
Morphological Properties ◽  
Fundamental Parameter ◽  
Fixed Temperature ◽  
Sensing Applications ◽  
Organometallic Precursor ◽  
Sem Analyses

Aim of the work is to compare the morphological properties of TiO2 powders obtained by different methods. The microstructure of powders is a fundamental parameter to judge if the material is suitable for gas sensing. Materials for chemical sensors have to be composed by nanometric and spherical shaped grains sintered in controlled conditions aimed to obtain Schottky barriers. We investigated a traditional sol-gel (SG) and an hydrothermal (HY) approach to obtain titanium dioxide powders. The same starting materials were chosen for both SG and HY method, a Ti-organometallic precursor and, as solvent, an hydroalcoholic solution. The work is focused on the different methodology and on the outcome related to the two methods (we describe step by step both of them). HY TiO2 powder shows smaller grains than SG TiO2 maintaining spherical shape. A comparison among different handled HY powders shows the role of dwelling time (at fixed temperature) on the nanostructure of grains. Experimental observations are mainly based on XRD and SEM analyses.

Role of Ga3+/Ti 4+ induced defects on UV sensing applications of Zn0.96875 (GaxTi 1-x) 0.03125 O

2020 ◽  
Author(s):  
Prashant Kumar Mishra ◽  
Saniya Ayaz ◽  
Gaurav Bajpai ◽  
Mohd. Nasir ◽  
Prashant Gupta ◽  
...  
Keyword(s):  
Sensing Applications ◽  
Induced Defects

The role of the polyelectrolyte composition in kinetic behaviour of organic memristive device

2021 ◽  
Vol 239-240 ◽  
pp. 111527
Author(s):  
Regina Burganova ◽  
Antonella Parisini ◽  
Salvatore Vantaggio ◽  
Roman Sajapin ◽  
Tatiana Berzina
Keyword(s):  
Memristive Device ◽  
Kinetic Behaviour

On the role of a coumarin derivative for sensing applications: Nucleotide identification using a micellar system

2016 ◽  
Vol 477 ◽  
pp. 8-15 ◽  
Author(s):  
Alexandre Bettoschi ◽  
Andrea Ceglie ◽  
Francesco Lopez ◽  
Valeria Meli ◽  
Sergio Murgia ◽  
...  
Keyword(s):  
Coumarin Derivative ◽  
Micellar System ◽  
Sensing Applications

The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh
Keyword(s):  
Biological Imaging ◽  
Ph Sensing ◽  
Hydrophobic Residue ◽  
Ideal Candidate ◽  
Self Assembling ◽  
Sensing Applications ◽  
Β Sheets ◽  
The Stability ◽  
Dynamics Simulations

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>

scholarly journals Review and outlook: from single nanoparticles to self-assembled monolayers and granular GMR sensors

2010 ◽  
Vol 1 ◽  
pp. 75-93 ◽  
Author(s):  
Alexander Weddemann ◽  
Inga Ennen ◽  
Anna Regtmeier ◽  
Camelia Albon ◽  
Annalena Wolff ◽  
...  
Keyword(s):  
Self Assembly ◽  
Self Assembled Monolayers ◽  
Interparticle Interactions ◽  
Phase Synthesis ◽  
Sensing Applications ◽  
Solution Phase Synthesis ◽  
Assembled Monolayers ◽  
Recent Developments ◽  
Gmr Sensors

This paper highlights recent advances in synthesis, self-assembly and sensing applications of monodisperse magnetic Co and Co-alloyed nanoparticles. A brief introduction to solution phase synthesis techniques as well as the magnetic properties and aspects of the self-assembly process of nanoparticles will be given with the emphasis placed on selected applications, before recent developments of particles in sensor devices are outlined. Here, the paper focuses on the fabrication of granular magnetoresistive sensors by the employment of particles themselves as sensing layers. The role of interparticle interactions is discussed.

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