Over the last four decades, research on DNA as a functional material has primarily focused on its predictable conformation and programmable interaction. However, its low energy consumption, high responsiveness and sen...
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Over the last four decades, research on DNA as a functional material has primarily focused on its predictable conformation and programmable interaction. However, its low energy consumption, high responsiveness and sensitivity also make it ideal for designing specific signaling pathways, and enabling the development of molecular computers. This review mainly discusses recent advancements in the utilization of DNA nanotechnology for molecular computer, encompassing applications in storage, cryptography and logic circuits. It elucidates the challenges encountered in the application process and presents solutions exemplified by representative works. Lastly, it delineates the challenges and opportunities within this filed.
Technology mapping is a process in logic synthesis for designing logic circuits. It converts an internal graph representation of logic functions into a gate-level netlist. This study proposes a method that involves in...
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Technology mapping is a process in logic synthesis for designing logic circuits. It converts an internal graph representation of logic functions into a gate-level netlist. This study proposes a method that involves introducing clockless gates proactively into resultant netlists of RSFQ logic circuits. Ordinary RSFQ circuits consist of clocked gates and necessitate path balancing. The usage of clockless gates working without clock inputs reduces the number of clocked gates and logic stages, which leads to a smaller clock distribution network. The capability of reducing the number of stages is essential to improve flexibility in the number of logic stages of designed circuits. The method introduces more clockless gates into the resultant netlist compared with our previous method instead of a longer clock period. It utilizes a specific library of supergates, that is, small single-output circuits with several logic gates, used in technology mapping. The library is generated by adding supergates that utilize clockless gates, except for their output parts, to an original library with no clockless gates. The method reduces the number of clocked gates to a greater extent than our previous method and gives designers a higher degree of flexibility in the number of logic stages. The evaluation results indicate that the number of clocked gates in netlists and logic stages is reduced by over 40% when compared with netlists without clockless gates.
logic circuits are the first step toward integrated circuits. Here, we fabricated the monolithically E/R logic, direct coupled E/E logic, and E/D inverter logic circuit with respective loads of resistor, enhancement f...
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logic circuits are the first step toward integrated circuits. Here, we fabricated the monolithically E/R logic, direct coupled E/E logic, and E/D inverter logic circuit with respective loads of resistor, enhancement field-effect transistor (FET), and depletion FET using hydrogenated diamond and observed the performance of these logic circuits. The gain and voltage swing of E/R logic circuits are strongly influenced by the value of the load resistance, which are commonly employed in separate components. E/E logic circuit exhibits small voltage swing, low gain, and low noise margin. E/D logic circuits present significant advantages in terms of voltage swing, gain, noise margins, and power consumption over E/R and E/E logic circuits. The E/D mode circuit shows a logic voltage swing of -9.44 V, a voltage gain of 15.5 V/V, low-/high-noise margins of 0.82/7.07 V, and static power consumption of 10(-3) W and proper functions up to at least 200 C-degrees at a supply voltage of -10 V. These results show great potential for diamond smart power integrated circuit application.
The demand for processing power has increased dramatically as a result of the growth of information technology. The traditional computing system has the fatal disadvantage of separating storage and computing. Many dat...
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We design logic circuits based on the notion of zero forcing on graphs;each gate of the circuits is a gadget in which zero forcing is performed. We show that such circuits can evaluate every monotone Boolean function....
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We design logic circuits based on the notion of zero forcing on graphs;each gate of the circuits is a gadget in which zero forcing is performed. We show that such circuits can evaluate every monotone Boolean function. By using two vertices to encode each logical bit, we obtain universal computation. We also highlight a phenomenon of "back forcing" as a property of each function. Such a phenomenon occurs in a circuit when the input of gates which have been already used at a given time step is further modified by a computation actually performed at a later stage. Finally, we show that zero forcing can be also used to implement reversible computation. The model introduced here provides a potentially new tool in the analysis of Boolean functions, with particular attention to monotonicity. Moreover, in the light of applications of zero forcing in quantum mechanics, the link with Boolean functions may suggest a new directions in quantum control theory and in the study of engineered quantum spin systems. It is an open technical problem to verify whether there is a link between zero forcing and computation with contact circuits.
As a first step to develop a diamond integrated circuit, hydrogenated diamond not and nor logic circuits composed of depletion-mode (D-mode) and enhancement-mode (E-mode) metal-oxide-semiconductor field-effect transis...
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As a first step to develop a diamond integrated circuit, hydrogenated diamond not and nor logic circuits composed of depletion-mode (D-mode) and enhancement-mode (E-mode) metal-oxide-semiconductor field-effect transistors (MOSFETs) are fabricated. The D-and E-modes MOSFETs act as load and driver devices for the logic circuits, respectively, which provides complementary transistor actions. The extrinsic transconductance maxima for both the MOSFETs are almost the same value of 17 mS mm(-1) and insensitive to device processing. With supply voltage changing from -5 to -25 V, gain maximum for not logic circuit increases from 1.2 to 26.1. The nor logic circuit shows clear nor gate characteristics.
We demonstrate logic circuits with field-effect transistors based on single carbon nanotubes. Our device layout features local gates that provide excellent capacitive coupling between the gate and nanotube, enabling s...
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We demonstrate logic circuits with field-effect transistors based on single carbon nanotubes. Our device layout features local gates that provide excellent capacitive coupling between the gate and nanotube, enabling strong electrostatic doping of the nanotube from p-doping to n-doping and the study of the nonconventional long-range screening of charge along the one-dimensional, nanotubes. The transistors show favorable device characteristics such as high gain (>10), a large on-off ratio (>10(5)), and room-temperature operation. importantly, the local-gate layout allows for integration of multiple, devices on a single chip. Indeed, we demonstrate one-, two-, and three-transistor circuits that exhibit a range of digital logic operations, such: as an inverter, a logic NOR, a static random-access memory cell, and an ac ring oscillator.
A full adder and a 1/2 frequency divider using resonant-tunneling hot-electron transistors (RHET's) have been proposed and demonstrated. These circuits make the best use of negative differential conductance, a fea...
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A full adder and a 1/2 frequency divider using resonant-tunneling hot-electron transistors (RHET's) have been proposed and demonstrated. These circuits make the best use of negative differential conductance, a feature of RHET's, and contain much fewer transistors than used in conventional circuits. They were fabricated using self-aligned InGaAs RHET's and WSiN thin-film resistors on a single chip. The RHET's have an i-InGaAlAs/i-InGaAs collector barrier that improves the current gain at low collector-base voltages. Circuit operation was confirmed at 77 K with a supply voltage of 3 V.
Gene digital circuits are the subject of many studies in Synthetic Biology due to their various applications from pollutant detection to medical diagnostics and biocomputing. Complex logic functions are calculated via...
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Gene digital circuits are the subject of many studies in Synthetic Biology due to their various applications from pollutant detection to medical diagnostics and biocomputing. Complex logic functions are calculated via small genetic components that mimic Boolean gates, i.e., they implement basic logic operations. Gates interact by exchanging proteins or noncoding RNAs. To carry out logic operations in the yeast Saccharomyces cerevisiae, we chose three bacterial repressors commonly used for proofs of concept in Synthetic Biology, namely, TetR, LexA, and LacI. We coexpressed them via synthetic polycistronic cassettes based on 2A peptide sequences. Our initial results highlighted the successful application of four 2A peptides -from Equine rhinitis B virus-1 (ERBV-1 2A), Operophtera brumata cypovirus 18 (OpbuCPV18 2A), Ljungan virus (LV2A), and Thosea asigna virus (T2A)-to the construction of single and two-input Boolean gates. In order to improve protein coexpression, we modified the original 2A peptides with the addition of the glycineserine-glycine (GSG) prefix or by using two different 2As sequences in tandem. Remarkably, we finally realized a well-working tricistronic vector that carried LexA-HBD(hER), TetR, and LacI separated, in the order, by GSG-T2A and ERBV-1 2A. This plasmid led to the implementation of three-input circuits containing AND and OR gates. Taken together, polycistronic constructs simplify the cloning and coexpression of multiple proteins with a dramatic reduction in the complexity of gene digital circuits.
The fluorescence behaviours of a chemical-sensitive fluorescent molecule 1,2-di[5-methoxy-2-(2-pyridiyl)thiazoyl]ethyne (DMPTE) at different protonation and coordination states were studied. Upon addition of protons, ...
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The fluorescence behaviours of a chemical-sensitive fluorescent molecule 1,2-di[5-methoxy-2-(2-pyridiyl)thiazoyl]ethyne (DMPTE) at different protonation and coordination states were studied. Upon addition of protons, metal ions and other chemicals, the fluorescent states can be switched reversibly. On the basis of the changes of fluorescence output signals from particular wavelengths in response to different combination sets of two particular external stimuli, the entire set of 2-bit Boolean binary logic functions were realized at the molecular level, including PASS 0, PASS 1, YES, NOT, OR, NOR, INHIBIT, IMPLICATION, AND, NAND, XOR, XNOR, and different logic functions were integrated reconfigurably within DMPTE. Besides, starting from the same initial state, a series of three-input logic gates and circuits were also constructed. Furthermore, the stepwise recognition process of DMPTE to different chemical input signals can also be utilized to distinguish different input sequences, thus a molecular keypad lock that authenticates three-digit password entries is indicated.
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