Logic Gate Circuits Research Articles

Construction of Boolean logic gates based on dual-vector circuits of multiple gene regulatory elements.

Gene circuits are constructed to run complex logical operations for the precise regulation of biological metabolic processes. At present, the implementation of most genetic circuits is based on the regulatory mechanism of various circuit components, but we hope to realize complex logic gates through biological metabolic pathways of organisms. In this study, we matched the regulatory elements of different functional mechanisms to build a Boolean logic gate model by means of a dual-vector circuit. In Escherichia coli, we made 12 circuit logic gate modules and validated the functions of four of the logic gates, including "AND", "NAND", "OR" and "NOR" by the expression and analysis of a reporter gene. The inputs were converted into outputs by an intermediate product of the host metabolism. The results indicated that these logic gate circuits had the expected efficacy and regulatory characteristics. Our study provides new ideas for designing genetic circuits and precisely controlling metabolic pathways.

Ring-Shaped Plasmonic Logic Gates

Ring-shaped one-, two-, and three-bit plasmonic logic gate configurations and circuits have been proposed, which, besides being compact, are also versatile and can be easily cascaded, the output logic values being controlled by both the geometry of the multi-port rings and the phase of the incident beams. This latter degree of freedom, not fully exploited up to now in plasmonic circuits, offers a high degree of flexibility of logic gate configurations.

Small Molecule Release and Activation through DNA Computing.

DNA-based logic gates can be assembled into computational devices that generate a specific output signal in response to oligonucleotide input patterns. The ability to interface with biological and chemical environments makes DNA computation a promising technology for monitoring cellular systems. However, DNA logic gate circuits typically provide a single-stranded oligonucleotide output, limiting the ability to effect biology. Here, we introduce a novel DNA logic gate design capable of yielding a small molecule output signal. Employing a Staudinger reduction as a trigger for the release and activation of a small molecule fluorophore, we constructed AND and OR logic gates that respond to synthetic microRNA (miRNA) inputs. Connecting the gates in series led to more complex DNA circuits that provided a small molecule output in response to a specific pattern of three different miRNAs. Moreover, our gate design can be readily multiplexed as demonstrated by simultaneous small molecule activation from two independent DNA circuits.

Universal interrogation protocol with zero probe-field-induced frequency shift for quantum clocks and high-accuracy spectroscopy

Optical clock interrogation protocols, based on laser-pulse spectroscopy, suffer from probe-induced frequency shifts and their variations induced by laser power. The original hyper-Ramsey probing scheme, which was proposed to alleviate those issues, does not fully eliminate the shift, especially when decoherence and relaxation by spontaneous emission or collisions are present. We propose to solve the fundamental problem of frequency shifts induced by the laser probe by deriving the exact canonical form of a multipulse generalized hyper-Ramsey resonance, including decoherence and relaxation. We present a universal interrogation protocol based on composite laser-pulse spectroscopy with phase modulation eliminating probe-induced frequency shifts at all orders in the presence of various dissipative processes. Unlike frequency shift extrapolation based methods, a universal interrogation protocol based on $\ifmmode\pm\else\textpm\fi{}\ensuremath{\pi}/4$ and $\ifmmode\pm\else\textpm\fi{}3\ensuremath{\pi}/4$ phase-modulated resonances is proposed which does not compromise the stability of the optical clock while maintaining an ultrarobust error signal gradient in the presence of substantial uncompensated ac Stark shifts. Such a scheme can be implemented in two flavors: either by inverting clock state initialization or by pulse order reversal even without a perfect quantum state initialization. This universal interrogation protocol can be applied to atomic, molecular, and nuclear frequency metrology, mass spectrometry, and the field of precision spectroscopy. It might be designed using magic-wave-induced transitions, two-photon excitation, and magnetically induced spectroscopy or it might even be implemented with quantum logic gate circuit and qubit entanglement.

Poly-4-vinylphenol (PVP) and Poly(melamine-co-formaldehyde) (PMF)-Based Atomic Switching Device and Its Application to Logic Gate Circuits with Low Operating Voltage.

In this study, we demonstrate a high-performance solid polymer electrolyte (SPE) atomic switching device with low SET/RESET voltages (0.25 and -0.5 V, respectively), high on/off-current ratio (105), excellent cyclic endurance (>103), and long retention time (>104 s), where poly-4-vinylphenol (PVP)/poly(melamine-co-formaldehyde) (PMF) is used as an SPE layer. To accomplish these excellent device performance parameters, we reduce the off-current level of the PVP/PMF atomic switching device by improving the electrical insulating property of the PVP/PMF electrolyte through adjustment of the number of cross-linked chains. We then apply a titanium buffer layer to the PVP/PMF switching device for further improvement of bipolar switching behavior and device stability. In addition, we first implement SPE atomic switch-based logic AND and OR circuits with low operating voltages below 2 V by integrating 5 × 5 arrays of PVP/PMF switching devices on the flexible substrate. In particular, this low operating voltage of our logic circuits was much lower than that (>5 V) of the circuits configured by polymer resistive random access memory. This research successfully presents the feasibility of PVP/PMF atomic switches for flexible integrated circuits for next-generation electronic applications.

Redox Active Binary Logic Gate Circuit for Homeland Security.

Bipolar junction transistors are at the frontiers of modern electronics owing to their discrete voltage regulated operational levels. Here we report a redox active binary logic gate (RLG) which can store a "0" and "1" with distinct operational levels, albeit without an external voltage stimuli. In the RLG, a shorted configuration of half-cell electrodes provided the logic low level and decoupled configuration relaxed the system to the logic high level due to self-charge injection into the redox active polymeric system. Galvanostatic intermittent titration and electrochemical quartz crystal microbalance studies indicate the kinetics of self-charge injection are quite faster and sustainable in polypyrrole based RLG, recovering more than 70% signal in just 14 s with minor signal reduction at the end of 10000 cycles. These remarkable properties of RLGs are extended to design a security sensor which can detect and count intruders in a locality with decent precision and switching speed.

Mechanistic modelling of a recombinase‐based two‐input temporal logic gate

Site-specific recombinases (SSRs) mediate efficient manipulation of DNA sequences in vitro and in vivo. In particular, serine integrases have been identified as highly effective tools for facilitating DNA inversion, enabling the design of genetic switches that are capable of turning the expression of a gene of interest on or off in the presence of a SSR protein. The functional scope of such circuitry can be extended to biological Boolean logic operations by incorporating two or more distinct integrase inputs. To date, mathematical modelling investigations have captured the dynamical properties of integrase logic gate systems in a purely qualitative manner, and thus such models are of limited utility as tools in the design of novel circuitry. Here, the authors develop a detailed mechanistic model of a two-input temporal logic gate circuit that can detect and encode sequences of input events. Their model demonstrates quantitative agreement with time-course data on the dynamics of the temporal logic gate, and is shown to subsequently predict dynamical responses relating to a series of induction separation intervals. The model can also be used to infer functional variations between distinct integrase inputs, and to examine the effect of reversing the roles of each integrase on logic gate output.

A rhodamine based fluorescent trivalent sensor (Fe3+, Al3+, Cr3+) with potential applications for live cell imaging and combinational logic circuits and memory devices

A novel sensor (HL5) recognizes sensitively and selectively trivalent metal ions M3+ (M = Al, Fe and Cr) with prominent enhancement in emission intensities with logic gate circuits and memory devices with living cell imaging application.

Teaching Practice for CMOS Inverter and Transmission Gate

CMOS inverter and transmission gate are the basic logic gate circuits in digital logic design and its application. They are also the digital circuits with which students first come into contact. Correctly understanding the inverter and the gate is the basis of learning other logic gate circuits. From the question existed in NMOS inverter to the formation of CMOS inverter and transmission gate, heuristic and discussion-based teaching method is applied in the course teaching. The process of problem solving is presented by guiding the students to analyze problems step by step. The practice results have shown that students’ interest in learning the course has been improved, and that the knowledge of context and the related knowledge of mutual relations have been mastered.

Reprogrammable Logic Gate and Logic Circuit Based on Multistimuli-Responsive Raspberry-like Micromotors.

In this paper, we report a polymer-based raspberry-like micromotor. Interestingly, the resulting micromotor exhibits multistimuli-responsive motion behavior. Its on-off-on motion can be regulated by the application of stimuli such as H2O2, near-infrared light, NH3, or their combinations. Because of the versatility in motion control, the current micromotor has great potential in the application field of logic gate and logic circuit. With use of different stimuli as the inputs and the micromotor motion as the output, reprogrammable OR and INHIBIT logic gates or logic circuit consisting of OR, NOT, and AND logic gates can be achieved.

Investigation of light doping and hetero gate dielectric carbon nanotube tunneling field-effect transistor for improved device and circuit-level performance

We perform a comparative study (both for device and circuit simulations) of three carbon nanotube tunneling field-effect transistor (CNT-TFET) designs: high-K gate dielectric TFETs (HK-TFETs), hetero gate dielectric TFETs (HTFETs) and a novel CNT-TFET-based combination of light doping and hetero gate dielectric TFETs (LD-HTFETs). At device level, the effects of channel and gate dielectric engineering on the switching and high-frequency characteristics for CNT-TFET have been theoretically investigated using a quantum kinetic model. This model is based on two-dimensional non-equilibrium Green’s functions solved self-consistently with Poisson’s equations. It is revealed that the proposed LD-HTFET structure can significantly reduce leakage current, enhance control ability of the gate on the channel, improve the switching speed, and is more suitable for use in low-power, high-frequency circuits. At circuit level, using HSPICE with look-up table-based Verilog-A models, the performance and reliability of CNT-TFET logic gate circuits is evaluated on the basis of power consumption, average delay, stability, energy consumption and power-delay product (PDP). Simulation results indicate that, compared to a traditional CNT-TFET-based circuit, the one based on LD-HTFET has a significantly better performance (static noise margin, energy, delay, PDP). It is also observed that our proposed design exhibits better robustness under different operational conditions by considering power supply voltage and temperature variations. Our results may be useful for designing and optimizing CNTFET devices and circuits.

Implementation Aspects of Logic Functions using Single Electron Threshold Logic Gates and Hybrid SET-MOS Circuits

ABSTRACTSingle electron technology is an attractive technology for future low-power VLSI/ULSI systems. Single electronics implies the possibility to control the movement and position of a single electron or a small amount of electrons. In this work, design, implementation, and analysis of logic functions are presented using single electron threshold logic gate (TLG) and hybrid SET-MOS circuits. The logic operation of the designed circuit is tested using Monte Carlo-based simulation tool SIMON for the single electron threshold logic circuit. For the hybrid SET-MOS-based implementation, the logic operation of the circuit is verified in Tanner environment. A compact analytical model with 11 island states for SET devices and BSIM4.6.1 model for MOS is used. The influence of thermal fluctuation on the stability of the threshold logic-based circuit, caused by increase in system temperature, has been thoroughly investigated. The effect of island states on the performance of the hybrid SET-MOS circuit is analysed. Finally, the performances of both the design approaches have been analysed and compared in terms of circuit elements, voltage levels, power consumption, and delay.

A New Class of Chaotic Circuit with Logic Elements

When signum operation is applied in chaotic systems to realize piecewise-linearity, the original nonlinearity turns to be a kind of Boolean calculation, and correspondingly the chaotic circuit can be implemented by an analog structure embedded with some logic-gate circuits. In this paper, as examples based on the diffusionless Lorenz system we proposed a couple of chaotic flows with signum piecewise-linearity, which experimentally resorts to digital gate circuits. The experimental chaotic circuit with logic elements was built, and the oscillation in the physical circuit agrees well with the numerical simulation.

Visual & reversible sensing of cyanide in real samples by an effective ratiometric colorimetric probe & logic gate application

A novel anion probe 3 (2,4-di-tert-butyl-6-((2(2,4-dinitrophenyl) hydrazono) methyl) phenol) has been unveiled as an effective ratiometric and colorimetric sensor for selective and rapid detection of cyanide. The sensing behavior was demonstrated by UV–vis experiments and NMR studies. This sensory system exhibited prominent visual color change toward cyanide ion over other testing anions in DMSO (90%) solvent, with a 1:1 binding stoichiometry and a detection limit down to 3.6×10−8molL−1. Sensor reveals specific anti-jamming activity and reversible in the presence of Cu2+ ions. This concept has been applied to design a logic gate circuit at the molecular level. Further we developed coated graphite electrode using probe 3 as ionophore and studied the performance characteristics of electrode. The sensitivity of ratiometric-based colorimetric assay is below the 1.9μM, accepted by the World Health Organization as the highest permissible cyanide concentration in drinking water. So it can be applied for both quantitative determination and qualitative supervising of cyanide concentrations in real samples.

Utilizing high resolution and reconfigurable patterns in combination with inkjet printing to produce high performance circuits

Inkjet printing on pre-fabricated high-resolution substrate is developed to improve the operational speed of printed organic transistors. The high-resolution features are designed to define transistor critical dimensions, while maintaining the flexibility to incorporate different circuit constructions. Logic gate and ring oscillator circuits fabricated by inkjet printing on the high-resolution substrate are demonstrated, to show that the same high resolution pattern can be adapted for constructing different electronic circuits.

The Realization of the 1/2 Blanking in the 4-1/2 Digital Voltmeter Based on ICL7135 Chip

It is necessary to realize the 1/2 blanking when designing the 4-1/2 digital voltmeter based on ICL7135 chip. The traditional digital voltmeter meters achieve the function by using the single-chip microcomputer program control. A new design should be considered when circuits are designed without the single-chip microcomputer. This paper combines the blanking terminal of the CD4511 decoding chip with the output signal of the A/D chip to design a complex logic gate circuit for realizing the blanking function. Experiment has been done to verify that the design of the complex logic gate circuit is feasible and it can guarantee the realization of the 1/2 blanking.

Titanium Oxide Memristor Based Digital Encoder Circuit

Memristors have the ability to remember their last resistance and quickly switch between different states, such characteristics could make logic circuits simple in structure and fast in boolean computations. A kind of digital encoder circuit utilizing titanium oxide memristors is proposed. A logic NAND gate which acts as key part in the circuit is designed. The works in this letter also provide a practical approach for designing logic gate circuit with memristors.

A new approach of developing all-optical two-bit-binary data multiplier

The demand of frequency encoded data based communication technology increases rapidly due to its inherent constancy throughout the communication of the signal. In this article the authors propose a new approach of developing all-optical two-bit binary data multiplier using frequency encoded binary data bits. The authors develop a unique method to design all optical AND logic gate and half adder circuit which are the basic building blocks of the multiplier circuit using nonlinear switching action and frequency conversion properties of semiconductor optical amplifier (SOA). Finally, the authors present the method to design two-bit-binary multiplier circuit. Simulation results reflect the feasibility of the proposed scheme. Efficient frequency conversion process, and, faster polarization switching of SOA with frequency encoded data offers bit error free secure multiplication operation with faster speed of processing.

Static and dynamic characteristics of dual gate organic TFT based NAND and NOR circuits

This research paper analyzes the static and dynamic behavior of dual-gate organic thin film transistors (DG-OTFTs) based universal logic gates using the Atlas 2-D numerical device simulator. The electrical characteristics and performance parameters of pentacene based DG-OTFT is evaluated and verified with respect to the reported experimental results. The NAND and NOR logic gate circuits are realized using $$p$$ p -type designs in diode-load logic (DLL) and zero- $$V_{gs}$$ V g s -load logic (ZVLL). The results show that the logic functions in ZVLL configuration outperforms the DLL ones mainly in terms of noise margin, gain and voltage swing; however, there is a trade-off in terms of speed. The ZVLL NAND gate demonstrates an increment of 16 and 32 % in voltage swing and noise margin, respectively in comparison to the DLL one. Besides this, the gain also increases by 1.5 times in ZVLL mode. On the contrary, the DLL configuration demonstrates a significant reduction of 64 % in the propagation delay in comparison to the ZVLL. Similarly, NOR gate shows an increment of 24 and 30 % in voltage swing and noise margin, respectively under ZVLL configuration. However, the propagation delay for DLL NOR configuration is one-fourth of that of its ZVLL counterpart.

A Proposed Exercise to Reinforce Abstract Thinking for Upper-Division Computer and Electrical Engineering Students: Modeling a High-Speed Inverter Using Cognitive Representations and Abstract Algebra

In mathematics, physics, and engineering, abstract concepts are an indispensable foundation for the study and comprehension of concrete models. As concepts within these fields become increasingly detached from physical entities and more associated with mental events, thinking shifts from analytical to conceptual-abstract. Fundamental topics taken from the abstract algebra (aka: modern algebra) are unquestionably abstract. Historically, fundamental concepts taught from the abstract algebra are detached from physical reality with one exception: Boolean operations. Even so, many abstract algebra texts present Boolean operations from a purely mathematical operator perspective that is detached from physical entities. Some texts on the abstract algebra introduce logic gate circuits, but treat them as perceptual symbols. For majors of pure or applied mathematics, detachments from physical entities is not relevant. For students of Computer and Electrical Engineering (CpE/EE), mental associations of Boolean operations are essential, and one might argue that studying pure Boolean axioms are unnecessary mental abstractions. But by its nature, the CpE/EE field tends to be more mentally abstract than the other engineering disciplines. The depth of the mathematical abstractions that we teach to upper-division CpE/EE majors is certainly up for questioning.