OR Logic Gates Research Articles

All-optical BCD to excess 3 code encoder with proper use of optical non-linear material

In the last few decades it has been established that, communication with light is much, much easier than communication with electricity. Many proposals have already been proposed in many fields in support of this. Here a new concept of all-optical binary to excess-3 code encoder or converter is proposed with the proper use of nonlinear optical material. In this scheme the input and output binary digits are expressed as the presence (= 1) and the absence (= 0) of the light signal. The intensity based optical XOR, AND and OR logic gates are used here as the basic building blocks.

Ionic Circuits Powered by Reverse Electrodialysis for an Ultimate Iontronic System

Despite numerous reports on iontronic devices, there has been no whole circuit working in aqueous media including even power source. Herein, we introduce complete ionic circuits powered by reverse electrodialysis (RED) for the first time without employing any electronic components. The RED-driven polyelectrolyte diode successfully shows rectification behavior which is verified by monitoring dynamic ion distribution through fluorescence in real-time. We can also turn on and off the voltage applied to the circuit, and apply an arbitrary voltage by precisely manipulating the pressure imposed to an elastic connection tube filled with electrolyte. Furthermore, this new concept containing ionic power source advances to a more sophisticated ionic OR logic gate. The proposed system paves the way to develop not only passive iontronic devices (e.g. current ionic diode), but active ones requiring a source of energy, particularly such as a neuron-like information processor powered by fully ionic systems, and thereby aqueous computers.

Functional Circuitry on Commercial Fabric via Textile-Compatible Nanoscale Film Coating Process for Fibertronics.

Fabric-based electronic textiles (e-textiles) are the fundamental components of wearable electronic systems, which can provide convenient hand-free access to computer and electronics applications. However, e-textile technologies presently face significant technical challenges. These challenges include difficulties of fabrication due to the delicate nature of the materials, and limited operating time, a consequence of the conventional normally on computing architecture, with volatile power-hungry electronic components, and modest battery storage. Here, we report a novel poly(ethylene glycol dimethacrylate) (pEGDMA)-textile memristive nonvolatile logic-in-memory circuit, enabling normally off computing, that can overcome those challenges. To form the metal electrode and resistive switching layer, strands of cotton yarn were coated with aluminum (Al) using a solution dip coating method, and the pEGDMA was conformally applied using an initiated chemical vapor deposition process. The intersection of two Al/pEGDMA coated yarns becomes a unit memristor in the lattice structure. The pEGDMA-Textile Memristor (ETM), a form of crossbar array, was interwoven using a grid of Al/pEGDMA coated yarns and untreated yarns. The former were employed in the active memristor and the latter suppressed cell-to-cell disturbance. We experimentally demonstrated for the first time that the basic Boolean functions, including a half adder as well as NOT, NOR, OR, AND, and NAND logic gates, are successfully implemented with the ETM crossbar array on a fabric substrate. This research may represent a breakthrough development for practical wearable and smart fibertronics.

Colorimetric biosensor based on a DNAzyme primer and its application in logic gate operations for DNA screening

A colorimetric biosensor for DNA screening was designed based on the conformational changes of the horseradish peroxidase (HRP)-mimicking DNAzyme. The scheme of DNA biosensing was designed based on the base pairing of DNAzyme sequence to inhibit the formation of HRP-mimicking hemin/G-quadruplex structures in the process of amplification. DNA could be amplified via the universal primer multiplex polymerase chain reaction (UP-M-PCR) and innovatively detected as color disappear in the reaction visible to the naked eye. The input of key factors and the output of optical characteristics in the reaction inspired the development of an OR logic gate operation for DNA detection. This biosensor overcomes self-inhibition and amplification disparity with the help of UP-M-PCR, thereby exhibiting high specificity and high-throughput without the requirement of gel analysis work. This biosensing system also presented 1% sensitivity and approximately 180 copy numbers in triplicate. The biosensor was used to screen elements from genetically modified organisms (GMOs) and covered more than 90% of all globally authorized events in the world. The designed colorimetric biosensor is a rapid, portable and versatile tool for nucleic acids detection and diagnosis in the field.

A State-of-the-Art Current Mirror-Based Reliable Wide Fan-in FinFET Domino OR Gate Design

With continued scaling of VLSI circuits, reliability has emerged out as one of the major circuit design challenges. Systematic die-to-die, random on-die as well as temperature and supply voltage variations are major sources of performance degradation which leads to unreliable circuits. Further, with reduced short channel effects at highly scaled nodes, the FinFET has recently been emerged as a suitable replacement of CMOS in the VLSI industry. Wide fan-in FinFET domino logic OR gate is one such circuit, which serves as an integral part of register file in a high-speed FinFET microprocessor. This circuit inherently suffers from low noise immunity which get worsens with circuit parameter variations due to process and temperature variations. At highly scaled technology nodes, it has been studied that the effects of on-die random process variation surpass the effects of systematic variations. Furthermore, at deep sub-nanometer scale the effect of process variation on device parameters is higher in FinFET as compared to CMOS. In this research work a reliable current mirror-based wide fan-in FinFET domino OR gate is proposed for temperature, random on-die and systematic die-to-die process variation tolerance. Simulation results at 32 nm FinFET process show that the proposed design is capable of maintaining high noise immunity (Unity Noise Gain of nearly 0.4 V) at all process corners and a constant performance (with reduced delay by 30% as compared to conventional design) in the presence of systematic as well as random process and temperature variations.

All-optical XOR and OR by Mach-Zehnder Interferometer engineered photonic crystal fibers

In this paper, we present a numerical investigation of all-optical logic gates based on a Mach-Zehnder Interferometer (MZI) configuration of micro structured fibers, also known as photonic crystal fibers (PCF) under optical OOK (on-off keying). We determine several relevant quantities to characterize the system performance, such as transmission and extinction ratio as a function of the nonlinearity profile (β) added to one of the Mach-Zehnder Interferometer (MZI) arms. High-order effects such as third-order dispersion, intrapulse Raman scattering and self-steepening were included in the generalized nonlinear Schrödinger equation describing the pulse propagation. For this study, we used an optical pulse with a shape of hyperbolic secant of 100fs (femtosecond). A pumped laser with three power values was simulated. With critical power Pc=103.5kW (P=Pc), below the critical power P=90kW (P<Pc) and above the critical power P=110kW (P>Pc). We added a nonlinearity profile in one of the Mach-Zehnder Interferometer (MZI) arms. Nonlinearity profiles were expressed in terms of the parameter β. We studied three different profiles: constant, increasing and decreasing. Our results show that the proposed device can be used to obtain all-optical OR and XOR logic gates as well as logic functions A and A.B¯. The OR logic gate was the one which achieved the greatest FOMELG (Figure of Merit of Logic Gates) when using increasing profile with critical power (P0=103.5kW) for β=1.05 and FOMELG=15.68dB. The XOR logic gate presented the greatest FOMELG=7.75dB when using the decreasing profile with power below the critical (P0=90kW) for β=1.44. These results provide support for applications in all-optical networks.

Multi-ion detection and molecular switching behaviour of reversible dual fluorescent sensor

The selective chemosensing behaviour of imidazole bisthiocarbohydrazone (IBTC) towards F− and Cu2+ are studied via colorimetric, UV–Visible, fluorescence spectra studies, and binding constants were calculated. The 1H NMR titration study strongly support that the deprotonation of IBTC followed by the hydrogen bond formation via N1H1 and N2H2 protons with fluoride ion. The fluorescence inactive IBTC-Cu complex became fluorescence active in the presence of perchlorate (ClO4−) ion. The selective detection of perchlorate ion was also explained. The F− sensing mechanism of IBTC has been investigated by Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TDDFT) methods. The theoretical outcomes well reproduce the experimental results. And it concluded the NH protons, nearby the imine group was first captured by the added F− ion and then deprotonation happened followed by the formation of hydrogen bond. The IBTC found good reversibility character with the alternative addition of Ca2+ and F−. The multi-ion detection of IBTC was used to construct the NOR, OR and INHIBITION molecular logic gates.

Self-Assembling Molecular Logic Gates Based on DNA Crossover Tiles.

DNA-based computational hardware has attracted ever-growing attention due to its potential to be useful in the analysis of complex mixtures of biological markers. Here we report the design of self-assembling logic gates that recognize DNA inputs and assemble into crossover tiles when the output signal is high; the crossover structures disassemble to form separate DNA stands when the output is low. The output signal can be conveniently detected by fluorescence using a molecular beacon probe as a reporter. AND, NOT, and OR logic gates were designed. We demonstrate that the gates can connect to each other to produce other logic functions.

Synthesis and spectral investigation of colorimetric receptors for the dual detection of copper and acetate ions: application in molecular logic gates

Colorimetric receptors L1, L2 and L3 possessing –OH functionality as binding site and –NO2 as signalling unit with varied positional substitution of –OMe functionality has been designed and synthesised by simple Schiff base condensation reaction. Receptors L1, L2 and L3 showed selective response towards AcO− ion among other interfering monovalent anions viz., F−, Cl−, Br−, I−, NO3−, and . L2 imparts high selectivity towards AcO− ion assisted by push-pull effect of –NO2 and –OMe functionality in conjugation with imine linkage. The binding constant for L2–OAc complex was found to be 9.04 × 104 M−2. L2 exhibited a detection limit of 0.61 ppm towards NaOAc. The selectivity of L1 towards Cu2+ ions with a lower detection limit of 1.81 ppm implies the role of electron donating –OMe in favouring the coordinative interaction of hetero atoms of L1 with Cu2+ ions. The selective detection of AcO− and Cu2+ ions is further established with OR and INHIBIT logic gate application of receptors L1, L2 and L3 correspondingly. The colorimetric studies reveal the role of OMe functionality in the selective detection of AcO− and Cu 2+ ions in aqueous media.

A single nano cantilever as a reprogrammable universal logic gate

The current transistor-based computing circuits use multiple interconnected transistors to realize a single Boolean logic gate. This leads to higher power requirements and delayed computing. Transistors are not suitable for applications in harsh environments and require complicated thermal management systems due to excessive heat dissipation. Also, transistor circuits lack the ability to dynamically reconfigure their functionality in real time, which is desirable for enhanced computing capability. Further, the miniaturization of transistors to improve computational power is reaching its ultimate physical limits. As a step towards overcoming the limitations of transistor-based computing, here we demonstrate a reprogrammable universal Boolean logic gate based on a nanoelectromechanical cantilever (NC) oscillator. The fundamental XOR, AND, NOR, OR and NOT logic gates are condensed in a single NC, thereby reducing electrical interconnects between devices. The device is dynamically switchable between any logic gates at the same drive frequency without the need for any change in the circuit. It is demonstrated to operate at elevated temperatures minimizing the need for thermal management systems. It has a tunable bandwidth of 5 MHz enabling parallel and dynamically reconfigurable logic device for enhanced computing.

Proof of principle of a three-input AND-INHIBIT-OR combinatorial logic gate array.

A designed molecule fluoresces according to a combinatorial logic circuit equivalent to wiring together three-input AND, three-input INHIBIT and two-input OR logic gates.

Electrogenerated chemiluminescence logic gate operations based on molecule-responsive organic microwires.

Complex logic gate operations using organic microwires as signal transducers based on electrogenerated chemiluminescence (ECL) intensity as the optical readout signal have been developed by taking advantage of the unique ECL reaction between organic semiconductor 9,10-bis(phenylethynyl)anthracene (BPEA) microwires and small molecules. The BPEA microwires, prepared on cleaned-ITO substrate using a simple physical vapor transport (PVT) method, were subsequently used for construction of the ECL sensors. The developed sensor exhibits high ECL efficiency and excellent stability in the presence of co-reactant tripropylamine. Based on the remarkable detection performance of BPEA MWs/TPrA system, the sensors manifested high sensitive ECL response in a wide linear range with low detection limit for the detection of dopamine, proline or methylene blue, which behaves on the basis of molecule-responsive ECL properties based on different ECL reaction mechanisms. Inspired by this, these sensing systems can be utilized to design OR, XOR and INHIBIT logic gates, which would be used for the determination of dopamine, proline and ethylene blue via logic outputs. Importantly, the individual logic gates can be easily brought together through three-input operations to function as integrated logic gates.

Spectroscopic and TDDFT investigation on highly selective fluorogenic chemosensor and construction of molecular logic gates

1,5-Bis(2-fluorene)thiocarbohydrazone (FBTC) was designed and synthesized for selective sensing of fluoride and copper ions. The binding constants of FBTC towards fluoride and copper ions have been calculated using the Benesi-Hildebrand equation, and FBTC has more binding affinity towards copper ion than fluoride ion. The 1H NMR and 13C NMR titration studies strongly support the deprotonation was taken from the N–H protons followed by the formation of hydrogen bond via N–H…F. To understand the fluoride ion sensing mechanism, theoretical investigation had been carried out using the density functional theory and time-dependent density functional theory. The theoretical data well reproduced the experimental results. The deprotonation process has a moderate transition barrier (481.55kcal/mol). The calculated ΔE and ΔG values (−253.92 and −192.41kcal/mol respectively) suggest the feasibility of sensing process. The potential energy curves give the optimized structures of FBTC-F complex in the ground state and excited state, which states the proton transition occurs at the excited state. The excited state proton transition mechanism was further confirmed with natural bond orbital analysis. The reversibility of the sensor was monitored by the alternate addition of F− and Cu2+ ions, which was explained with “Read-Erase-Write-Read” behaviour. The multi-ion detection of sensor used to construct the molecular logic gate, such as AND, OR, NOR and INHIBITION logic gates.

Realization of Ultra-Accurate and Compact All-Optical Photonic Crystal OR Logic Gate

By unique combination of single-line defects, Mach-Zehnder interferometer, and ring resonators, we propose a novel, easy-to-fabrication and linear scheme for realizing accurate and compact all-optical OR logic gate based on 2-D photonic crystal structures. To obtain the transmission spectra of the structure, we considered the entire structure as a single cavity and then we applied a fast Fourier transform to the transmitted spectral power densities at the output port and the unexcited input port; this strategy enhances the control on unwanted port-to-port power reflections and hence increasing the distinction between logic levels. Simulating the electromagnetic wave propagation in the proposed device reveals that the accurate all-optical OR logic gate is obtained. The achieved contrast ratio between logic levels is $\sim 7.27$ dB. Moreover, since all ports are located on the same side and the size of the structure is $12.5~\mu \text{m} \times 16~\mu \text{m}$ . It is fully compacted and has the ability of dense integration. The proposed structure is completely easy-to-fabrication and designed for using in future high accuracy photonic integrated circuits.

Numerically simulation of soliton OR gate with semiconductor optical amplifier-assisted delayed interferometer

Solitons are caused by a cancellation of nonlinear and dispersive effects in the medium. The performance of a soliton all-optical logic OR gate is numerically simulated at a repetition rate of 80 Gb/s. This Boolean function is realized by using a semiconductor optical amplifier (SOA)-assisted delayed interferometer (DI). The dependence of the output quality factor (Q-factor) on the soliton characteristics and SOA’s parameters has been examined and assessed. The obtained results confirm that the soliton all-optical logic OR gate implemented with logical correctness, high output and clear Q-factor.

Fluorescent Sensing of both Fe(III) and pH Based on 4-Phenyl-2-(2-Pyridyl)Thiazole and Construction of OR Logic Function.

In the presented paper we investigated a 2-pyridylthiazole derivative, 4-phenyl-2-(2-pyridyl)thiazole (2-PTP), as the molecular fluorescent switches. It was firstly found that 2-PTP could perform a "turn-on" fluorescent sensing for Fe(III) with selectivity and reversibility. A 2:1 stoichiometry between 2-PTP and Fe(III) was determined according to the molar ratio method. The binding constant was evaluated as (1.90±0.05)×10(5) (L/mol)(2). The detection limit was found as 2.2×10(-7)M (S/N=3). Secondly, 2-PTP also exhibited a pH-dependent dual-emission. The pK a(2-PTP-H(+)/2-PTP) value was then estimated as 2.0. To explain the identical emission at 479nm of both the Fe(III) coordinated form and the protonated form of the ligand, we proposed a "locked" conformation. Finally, combining the two external stimuli as inputs, an OR logic gate was constructed using the fluorescent emission at 479nm as the output channel.

Sub-kBT micro-electromechanical irreversible logic gate.

In modern computers, computation is performed by assembling together sets of logic gates. Popular gates like AND, OR and XOR, processing two logic inputs and yielding one logic output, are often addressed as irreversible logic gates, where the sole knowledge of the output logic value is not sufficient to infer the logic value of the two inputs. Such gates are usually believed to be bounded to dissipate a finite minimum amount of energy determined by the input–output information difference. Here we show that this is not necessarily the case, by presenting an experiment where a OR logic gate, realized with a micro-electromechanical cantilever, is operated with energy well below the expected limit, provided the operation is slow enough and frictional phenomena are properly addressed.

All-optical switches, unidirectional flow, and logic gates with discrete solitons in waveguide arrays.

We propose a mechanism by which a number of useful all-optical operations, such as switches, diodes, and logic gates, can be performed with a single device. An effective potential well is obtained by modulating the coupling between the waveguides through their separations. Depending on the power of a control soliton injected through the potential well, an incoming soliton will either completely transmit or reflect forming a controllable switch. We show that two such switches can work as AND, OR, NAND, and NOR logic gates. Furthermore, the same device may also function as a perfect soliton diode with adjustable polarity. We discuss the feasibility of realising such devices with current experimental setups.

A Simple and Selective Fluorescent Sensor for Zn(2+) and H(+) Ions in Aqueous Solution with OR Logic Gate Function.

The synthesis and properties of a new compound, viz., (N,N'-[1,10-phenanthroline-4,7-diyldi((E)methylylidene)]bis(1,10-phenanthrolin-5-amine) (1), is described. Compound 1 can be used as a selective fluorescent Zn(2+) sensor in buffered solution. Furthermore, 1 induces turn on fluorogenic response to H(+) ions. Finally, it is shown that an OR logic gate can be constructed with 1 by using Zn(2+) and H(+) as two-inputs. Graphical Abstract In this paper, the design, synthesis and physicochemical properties of a new compound 1 based on 1,10-phenanthroline scaffold, is reported. It is noted that 1 can be used as a selective fluorescent Zn(2+) sensor in 0.01M HEPES buffer containing DMF (2%v/v, pH=7.4) at room temperature. Furthermore, the spectrophotometric results suggest that compound 1 can be used as a pH reporter in highly acidic conditions (pH<5). Finally, it was also shown that an OR logic gate can be constructed with 1 by using Zn(2+) and H(+) as two-inputs.

Phase-shift-controlled logic gates in Y-shaped nonlinearly coupled chains.

We introduce a model system composed of two input discrete chains nonlinearly coupled to a single output chain which mimics the geometry of Y-shaped carbon nanotubes, photonic crystal wave guides, and DNA junctions. We explore the capability of the proposed system to perform logic gate operations based on the transmission of phase-shifted harmonic incoming waves. Within a tight-binding approach, we determine the exact transmission spectrum which exhibits a nonlinear induced bistability. Using a digitalization scheme of the output signal based on amplitude modulation, we show that AND, OR, and XOR logic operations can be achieved. Nonlinearity strongly favors the realization of logic operations in the regime of large wavelengths, while phase shifting is required for the OR logic gate to be realizable. A detailed analysis of the contrast ratio shows that optimal operation of the AND and OR logic gates takes place when the nonlinear response is the predominant physical property distinguishing the coupling and regular sites. These results point towards the possibility of Y-branched junctions to perform logic operations based on the transmission of traveling waves.