Circuit Patterns Research Articles

Multiple Missing Cell Defect Modeling for QCA Devices

Considering the limitations of CMOS technology, the Quantum-dot Cellular Automata (QCA) is emerging as one of the alternatives for Integrated Circuit (IC) Technology. A lot of work is being carried out for design, fabrication and testing of QCA circuits. In this paper, we have worked on defect analysis, fault models development and deriving various properties for QCA Majority Voter (MV) to effectively generate the test patterns for QCA circuits. It has been shown that unlike CMOS technology, single missing cell consideration is not enough for QCA technology. We have presented that the Multiple Missing Cell (MMC) defect, which is very natural at nanoscale, causes the sizable difference in functionality compared to Single Missing Cell consideration described in literature, and hence, must be considered while test generation. The proposed MMC is supported by exhaustive simulation results as well as kink energy based mathematical analysis. Further, Verilog fault models are proposed which can be used for the functional, timing verification and activation of faults caused by MMC defect. The effect of MMC on output is analyzed in stand-alone MV as well as when MV is a part of circuit. At the end, we have proposed the test properties of MV when being used as MV itself, as AND gate or OR gate. These properties may be further helpful in development of test generation algorithms.

Shin-Etsu to boost photomask output

Shin-Etsu Chemical will spend $125 million to expand photomask blank output at its Takefu and Naoetsu sites in Japan. The investment will raise Shin-Etsu’s capacity by 30% when completed in 2021. Shin-Etsu sells its quartz blanks to semiconductor firms, which draw integrated circuit patterns on them. The patterns are transferred onto silicon wafers—which Shin-Etsu also produces—via photolithography.

Dendritic spine remodeling accompanies Alzheimer's disease pathology and genetic susceptibility in cognitively normal aging.

Subtle alterations in dendritic spine morphology can induce marked effects on connectivity patterns of neuronal circuits and subsequent cognitive behavior. Past studies of rodent and nonhuman primate aging revealed reductions in spine density with concomitant alterations in spine morphology among pyramidal neurons in the prefrontal cortex. In this report, we visualized and digitally reconstructed the three-dimensional morphology of dendritic spines from the dorsolateral prefrontal cortex in cognitively normal individuals aged 40-94years. Linear models defined relationships between spines and age, Mini-Mental State Examination, apolipoprotein E (APOE) ε4 allele status, and Alzheimer's disease (AD) pathology. Similar to findings in other mammals, spine density correlated negatively with human aging. Reduced spine head diameter associated with higher Mini-Mental State Examination scores. Individuals harboring an APOE ε4 allele displayed greater numbers of dendritic filopodia and structural alterations in thin spines. The presence of AD pathology correlated with increased spine length, reduced thin spine head diameter, and increased filopodia density. Our study reveals how spine morphology in the prefrontal cortex changes in human aging and highlights key structural alterations in selective spine populations that may promote cognitively normal function despite harboring the APOE ε4 allele or AD pathology.

Highly Robust, Transparent, and Breathable Epidermal Electrode.

Recently emerged electronic skins with applications in on-body sensing and human-machine interfaces call for the development of high-performance skin-like electrodes. In this work, we report a highly robust, transparent, and breathable epidermal electrode composed of a scaffold-reinforced conductive nanonetwork (SRCN). Solution-dispersed Ag nanowires, through facile vacuum filtration, are embedded into a scaffold made of polyamide nanofibers. Optical transmittance of 84.9% at 550 nm wavelength is achieved at a significantly low sheet resistance of 8.2 Ω sq-1. The resistance of the SRCN only slightly increases by less than 0.1% after being bent for 3000 cycles at the maximum curvature of 300 m-1 and by less than 1.5% after being dipped in saline solution for 2500 cycles. The excellent robustness is attributed to the reinforcement from the nanofiber-based scaffold as a backbone that maintains the connections among the Ag nanowires by undertaking most of the loaded stress. The SRCN not only forms tight and conformal bonding with the target surface but also allows the evaporation of perspiration, making it suitable as an epidermal electrode for long-time use. Furthermore, fine and clean-cut circuit patterns with a line width on the micrometer scale can be readily prepared, paving the way for fabricating sophisticated functional electronic skins.

Parallel ring‐line rat‐race circuit with very loose coupling

AbstractThis article describes rat‐race circuits (RRCs) in which a pair of ring‐lines have parallel lines of ±180‐degree difference for electrical length to realize the RRC with very loose coupling such as −10 dB or less. The proposed RRCs with parallel ring‐lines realize a coupling factor of −10 dB and −20 dB by using moderate characteristic impedance lines with a view point of fabrication tolerance for general PCB technologies. We confirm the validity of this circuit construction and design method using a commercial electromagnetic simulator and decide the circuit pattern for fabrication at a center frequency of 2.45 GHz. The fabricated RRCs with parallel ring‐lines realize the desired coupling factors and in‐/out‐of‐phase outputs, and the measurement results of scattering parameters for −10 dB and −20 dB RRCs are in good agreement with the simulation results.

GABRA2 rs279858-linked variants are associated with disrupted structural connectome of reward circuits in heroin abusers

The reward system plays a vital role in drug addiction. The purpose of this study is to investigate the structural connectivity characteristics and driving-control subnetwork patterns of reward circuits in heroin abusers and assess the genetic modulation on the reward network. We first defined the reward network based on systematic literature review, and built the reward network based on diffusion tensor imaging data of 78 heroin abusers (HAs) and 79 healthy controls (HCs) using structural connectomics. Then we assessed genetic factors that might modulate changes in the reward network by performing imaging-genetic screening for 22 addiction-related polymorphisms. The genetic association was validated by performing genetic associations (1032 HAs and 2863 HCs) and expanded-variant analysis. Finally, we estimated the association between these genetic variations, reward network, and clinical performance. We found that HAs had widespread deficiencies in the structural connectivity of the reward circuit (center in VTA-linked connections), which correlated with cognition deficiency. The disruptions synchronously were shown on the reward driving system and reward control system. GABRA2 rs279858-linked variants might be a key genetic modulator for heroin vulnerability by affecting the connections of reward network and cognition. The role of the reward network connections that mediates the effects of rs279858 on cognition would be disrupted by heroin addiction. These findings provide new insights into the neurocircuitry and genetic mechanisms of addiction.

Machine vision based in-process light-emitting diode chip mounting system

Background: In this study, a machine vision–based method was developed for automated in-process light-emitting diode chip mounting lines with position uncertainty. In order to place the tiny light-emitting diode chips on the pattern of a printed circuit board, a highly accurate mounting process is achieved with online feedback of the visual assistance. Methods: The system consists of a charge-coupled device camera, a six-axis robot arm, and a delta robot. The lighting system is a critical point for the in-process machine vision problem. Hence, designing the optimal lighting solution is one of the most difficult parts of a machine vision system, and several lighting techniques and experiments are examined in this study. In order to commence the mounting process, the light-emitting diode chip targets inside the camera field were identified and used to guide the delta robot to the grabbing zone based on the calibrated homography transformation. Efforts have been focused on the field of machine vision–based feature extraction of the chip pins and the holes on the printed circuit board. The correspondence of each other is determined by the position of the chip pins and the printed circuit board circuit pattern. The image acquisition is achieved directly online in real time. The image analysis algorithm must be sufficiently fast to follow the production rate. In order to compensate for the uncertainty of the light-emitting diode chip mounting process, a visual feedback strategy in conjunction with an uncertainty compensation strategy is employed. Results: Finally, the light-emitting diode chip was automatically grabbed and accurately placed at the desired positions. Conclusion: On-line and off-line experiments were conducted to investigate the performance of the vision system with respect to detecting and mounting light-emitting diode chips.

Novel method for the design of radiant floor cooling systems through homogenizing spatial solar radiation distribution

The local and mobile incident sunlight from skylight and side windows shining on the floor surface increases the cooling capacity of the radiant floor cooling system. In this study, a novel method of homogenizing spatial solar radiation distribution over the entire radiant floor surface is proposed to the design of the radiant floor with a conventional circuit pattern of counter flow. A verified three-dimensional numerical radiant floor model is utilized to evaluate the deviation of the novel method in steady and transient states. The simulation results indicate that the relative error for local sunlight with a width over two pipe spacing is less than 1.0%. With a solar radiation intensity of 300 W/m2, the deviation of the simulated floor surface heat flux via the novel method is less than 0.3 W/m2 for any sunlight size in steady states. Furthermore, under transient and mobile sunlight, the simulated water side and floor surface heat fluxes via the novel method agrees well with the 3D model. As a result, the homogenizing treatment significantly simplifies the dynamic analysis of radiant floor system under temporal and spatial solar radiation distribution with enough accuracy in engineering applications.

Liquid-metal circuit can be printed and peeled

A new print-and-peel method for making stretchable electronics is based on liquid metals (iScience 2018, DOI: 10.1016/j.isci.2018.05.013). Gallium-based alloys are highly conductive and liquid at low temperatures, so they can serve as conductors in soft electronics that must bend and flex. Researchers can print custom circuit patterns using liquid-metal inks created by dispersing droplets of the alloy in a solvent. But droplets of gallium alloys quickly form a thin oxide skin, inhibiting conductivity in the printed pattern. To overcome that issue, a team led by Xingyu Jiang of China’s National Center for Nanoscience & Technology screen-printed a eutectic gallium-indium alloy onto a plastic substrate, then cast a flexible rubber layer on top of the liquid-metal pattern. After the rubber cured around the pattern, they peeled the rubber off. The oxide layer surrounding each droplet tends to stick to the substrate as the pattern is pulled away, so the oxide skin

Postnatal colonization with human "infant-type" Bifidobacterium species alters behavior of adult gnotobiotic mice.

Accumulating studies have defined a role for the intestinal microbiota in modulation of host behavior. Research using gnotobiotic mice emphasizes that early microbial colonization with a complex microbiota (conventionalization) can rescue some of the behavioral abnormalities observed in mice that grow to adulthood completely devoid of bacteria (germ-free mice). However, the human infant and adult microbiomes vary greatly, and effects of the neonatal microbiome on neurodevelopment are currently not well understood. Microbe-mediated modulation of neural circuit patterning in the brain during neurodevelopment may have significant long-term implications that we are only beginning to appreciate. Modulation of the host central nervous system by the early-life microbiota is predicted to have pervasive and lasting effects on brain function and behavior. We sought to replicate this early microbe-host interaction by colonizing gnotobiotic mice at the neonatal stage with a simplified model of the human infant gut microbiota. This model consortium consisted of four “infant-type” Bifidobacterium species known to be commensal members of the human infant microbiota present in high abundance during postnatal development. Germ-free mice and mice neonatally-colonized with a complex, conventional murine microbiota were used for comparison. Motor and non-motor behaviors of the mice were tested at 6–7 weeks of age, and colonization patterns were characterized by 16S ribosomal RNA gene sequencing. Adult germ-free mice were observed to have abnormal memory, sociability, anxiety-like behaviors, and motor performance. Conventionalization at the neonatal stage rescued these behavioral abnormalities, and mice colonized with Bifidobacterium spp. also exhibited important behavioral differences relative to the germ-free controls. The ability of Bifidobacterium spp. to improve the recognition memory of both male and female germ-free mice was a prominent finding. Together, these data demonstrate that the early-life gut microbiome, and human “infant-type” Bifidobacterium species, affect adult behavior in a strongly sex-dependent manner, and can selectively recapitulate the results observed when mice are colonized with a complex microbiota.

Closed Loop Deep Brain Stimulation for PTSD, Addiction, and Disorders of Affective Facial Interpretation: Review and Discussion of Potential Biomarkers and Stimulation Paradigms.

The treatment of psychiatric diseases with Deep Brain Stimulation (DBS) is becoming more of a reality as studies proliferate the indications and targets for therapies. Opinions on the initial failures of DBS trials for some psychiatric diseases point to a certain lack of finesse in using an Open Loop DBS (OLDBS) system in these dynamic, cyclical pathologies. OLDBS delivers monomorphic input into dysfunctional brain circuits with modulation of that input via human interface at discrete time points with no interim modulation or adaptation to the changing circuit dynamics. Closed Loop DBS (CLDBS) promises dynamic, intrinsic circuit modulation based on individual physiologic biomarkers of dysfunction. Discussed here are several psychiatric diseases which may be amenable to CLDBS paradigms as the neurophysiologic dysfunction is stochastic and not static. Post-Traumatic Stress Disorder (PTSD) has several peripheral and central physiologic and neurologic changes preceding stereotyped hyper-activation behavioral responses. Biomarkers for CLDBS potentially include skin conductance changes indicating changes in the sympathetic nervous system, changes in serum and central neurotransmitter concentrations, and limbic circuit activation. Chemical dependency and addiction have been demonstrated to be improved with both ablation and DBS of the Nucleus Accumbens and as a serendipitous side effect of movement disorder treatment. Potential peripheral biomarkers are similar to those proposed for PTSD with possible use of environmental and geolocation based cues, peripheral signs of physiologic arousal, and individual changes in central circuit patterns. Non-substance addiction disorders have also been serendipitously treated in patients with OLDBS for movement disorders. As more is learned about these behavioral addictions, DBS targets and effectors will be identified. Finally, discussed is the use of facial recognition software to modulate activation of inappropriate responses for psychiatric diseases in which misinterpretation of social cues feature prominently. These include Autism Spectrum Disorder, PTSD, and Schizophrenia—all of which have a common feature of dysfunctional interpretation of facial affective clues. Technological advances and improvements in circuit-based, individual-specific, real-time adaptable modulation, forecast functional neurosurgery treatments for heretofore treatment-resistant behavioral diseases.

Voxel-wise brain-wide functional connectivity abnormalities in first-episode, drug-naive patients with major depressive disorder.

Due to different foci and single sample across studies, abnormal functional connectivity (FC) has been implicated in the pathophysiology of major depressive disorder (MDD) with inconsistent results. The inconsistency may reflect a combination of clinical and methodological variability, which leads to limited reproducibility of these findings. The samples included 59 patients with MDD and 31 controls from Sample 1, 29 patients with MDD and 24 controls from Sample 2, and 31 patients with schizophrenia and 37 controls from Sample 3. Global-brain FC (GFC) and an overlapping technique were applied to analyze the imaging data. Compared with healthy controls, patients with MDD in Samples 1 and 2 showed increased GFC in the overlapped brain areas, including the bilateral insula, right inferior parietal lobule (IPL), and right supramarginal gyrus/IPL. By contrast, decreased GFC in the overlapped brain areas, including the bilateral posterior cingulate cortex/presuneus and left calcarine cortex, was found in patients with MDD. In addition, patients with schizophrenia in Sample 3 did not show any GFC abnormalities in the overlapped areas from the results of Samples 1 and 2. The present study is the first to examine voxel-wise brain-wide FC in MDD with two independent samples by using an overlapping technique. The results indicate that aberrant FC patterns of insula-centered sensorimotor circuit may account for the pathophysiology of MDD.

In-Plane Growth of Poly(3,4-ethylenedioxythiophene) Films on a Substrate Surface by Bipolar Electropolymerization.

Alternating current (AC) bipolar electropolymerization of 3,4-ethylenedioxythiophene (EDOT) using a gold (Au) wire as a bipolar electrode (BPE) on a substrate surface resulted in gradual growth of the corresponding poly(3,4-ethylenedioxythiophene) (PEDOT) thin film from the terminals of the Au wire on the substrate. Studies to clarify the polymerization behavior were conducted under various electrolytic conditions, including monomer concentration, applied frequency, monomer structure, and substrate material. This method could be used to draw conducting polymer films on a nonconductive substrate, guided by an applied external electric field, and thus has potential for circuit patterning in organic electronic devices.

Thin and Thick Film Ceramic-Based Passive Wireless Temperature Sensors for Harsh Environments

The needs for real-time temperature monitoring of energy systems in extreme conditions keeps increasing due to the growth of manufacturing industries. Current technologies utilize thermocouples, infrared laser interferometers, and surface acoustic wave (SAW) sensors. Thermocouples have limited lifespan. The reliability is poor due to continuous redox reaction taking place at the hot junction and any caustic environment will corrode the thermocouple material. Laser interferometers are limited by the spot area of the laser beam and monitoring temperature gradient is difficult, since it is a surface sensitive technique. To overcome the limitations, research has been focused on passive wireless sensor technology where an inductor–capacitor (LC) circuit was used to monitor the temperature and local strain conditions. The primary objective of this work was to study the materials properties of carbide/silicide and oxide composites for the fabrication of ceramic-based LC circuits on a ceramic substrate using thin and thick film deposition methods. This work includes the investigation of the composite precursor, pattern technology and the effect of thermal processing on the final pattern and stability. The relation of volume shrinkage during sintering process and phase development are of interest. The secondary objective of this work was to investigate the electrical properties of the tailored sintered electrodes. One system that will be discussed is the development of a polymer-derived electroceramic electrodes based on two different carbide/silicide compositions. These inks were synthesized by mixing a siloxane/silane compound with an active inorganic filler material. Upon sintering, the organic molecules decomposed and the silicon will react with the inorganic fill at a higher temperature to form a ceramic composite. The reaction kinetics depends on the reaction between terminating functional groups, silicon ``atom, and the filler particle. To understand the reaction kinetics, phase formation, and other mechanical properties (such as volumetric shrinkage), varying ratios of the particle filled polymer matrix was injection molded and sintered at varying temperature rates. The compositions that provided the desired material properties was chosen to direct-write the LC circuit pattern on a ceramic substrate by a 2D printing technology and screen printing technology. The sintered sensor was characterized by XRD, SEM and the electrical characterization of the printed LC circuits were completed on the sensor compositions by a signal analyzer in tandem with an oscilloscope (at temperatures 50-1300oC). Miniaturization of the LC circuit was developed by a thin film deposition process to show the effect of size reduction in various aspects of sensing and adaptability. Miniaturized LC circuit was patterned by depositing by physical vapor deposition onto a ceramic substrate. Additionally, the size reduction will boost the capacitance of the circuit which will assist in the reduction of the signal-to-noise ratio, ease of signal processing and reduces the sophistication of electronics. The fabricated thin films were characterized by grazing incident XRD and SEM to compare the formation of grain boundaries, phases with the thick film composite. The electrical characterization was completed in a similar fashion to compare results with thick film composites.

40.2: Integrated Solution for Roll‐to‐Roll Fine Copper Circuit Touch Sensor Making

Applying common photolithography process to flexible substrate with novel formulated lithographic chemicals, flexible touch sensor film can be manufactured by roll‐to‐roll process. Extremely fine copper pattern (<2um) could be obtained without using fine mask pattern and with no copper damaging. With proprietary low temperature curing flexible black matrix photoresist to make the fringe, all layers of metal mesh touch sensor can be integrated onto one film substrate to achieve true flexible touch for flexible displays. This integrated solution is enabled by four new formulated materials: one low temperature curing black matrix photoresist for fringe, one flexible positive‐tone photoresist and one copper etchant for fine circuit patterning, and one low temperature curing clear photoresist for passivation.

Characterization of carbon nanofiber (CNF)/polymer composite coated on cotton fabrics prepared with various circuit patterns

Fabric heating elements with carbon nanofiber (CNF)/Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite coated cotton fabrics were prepared with various circuit patterns with the aim of providing more flexible and uniform heating performance compared to conventional fabric heating elements. To investigate the properties of the fabric heating element according to the pattern condition, patterns consisting of 3, 5, and 7 horizontal lines, i.e., P3, P5 and P7, were respectively used; and subsequently, vertical lines were added to the horizontal lines, i.e., 2P3, 2P5 and 2P7, respectively. P0 was used as the referencesample. P0 showed a surface resistance of 1.2 × 103 Ω/sq at a current of 0.85 A and an electric heating temperature of 76.9 °C. P3 and 2P3 showed better electrical and electric heating properties than other samples, showing surface resistance values of 1.0 × 103 and 1.2 × 103 Ω/sq at the current values of 0.20 and 0.25 A, and surface temperatures of 71.8 and 75.7 °C, respectively. Although the currents applied to P3 and 2P3 were lower than that applied to P0, the electrical heating properties were modified to be similar. In terms of mechanical properties and water repellency, it was shown that the coated fabrics had higher values compared to the uncoated fabric. It was thus suggested that a small amount of CNF/PVDF-HFP composite can be used to manufacture an electric heating element with excellent performance.

Selective electroless metallization of non-conductive substrates enabled by a Fe3O4/Ag catalyst and a gradient magnetic field

The formation of printed circuit patterns on non-conductive substrates has many applications in high value sectors such as electronics manufacturing. Current semi-additive and subtractive circuit manufacturing processes use photolithography to pattern substrates coated with a thin or relatively thick metal film. This process is often wasteful and expensive. Using an innovative approach; composite Fe3O4-Ag nanoparticles were synthesized and attracted to a magnetic field. The nanoparticles catalysed electroless copper deposition. Such a catalyst is new to electroless plating and was deposited selectively on a dielectric substrate using a gradient magnetic field. In this way, subsequent electroless copper plating occurred exclusively where the magnetic field was applied, whilst the remaining surface was free of deposited metal. The advantage of this additive method of manufacture is that less material is needed and less waste is produced.

Fully Solution-Processable Fabrication of Multi-Layered Circuits on a Flexible Substrate Using Laser Processing.

The development of printing technologies has enabled the realization of electric circuit fabrication on a flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag) nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of the laser focal position and intensity. Based on these methods, a flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated to have functional operations.

An FGF-driven feed-forward circuit patterns the cardiopharyngeal mesoderm in space and time.

In embryos, multipotent progenitors divide to produce distinct progeny and express their full potential. In vertebrates, multipotent cardiopharyngeal progenitors produce second-heart-field-derived cardiomyocytes, and branchiomeric skeletal head muscles. However, the mechanisms underlying these early fate choices remain largely elusive. The tunicate Ciona emerged as an attractive model to study early cardiopharyngeal development at high resolution: through two asymmetric and oriented divisions, defined cardiopharyngeal progenitors produce distinct first and second heart precursors, and pharyngeal muscle (aka atrial siphon muscle, ASM) precursors. Here, we demonstrate that differential FGF-MAPK signaling distinguishes between heart and ASM precursors. We characterize a feed-forward circuit that promotes the successive activations of essential ASM determinants, Hand-related, Tbx1/10 and Ebf. Finally, we show that coupling FGF-MAPK restriction and cardiopharyngeal network deployment with cell divisions defines the timing of gene expression and permits the emergence of diverse cell types from multipotent progenitors.

Optimized connectome architecture for sensory-motor integration.

The intricate connectivity patterns of neural circuits support a wide repertoire of communication processes and functional interactions. Here we systematically investigate how neural signaling is constrained by anatomical connectivity in the mesoscale Drosophila (fruit fly) brain network. We use a spreading model that describes how local perturbations, such as external stimuli, trigger global signaling cascades that spread through the network. Through a series of simple biological scenarios we demonstrate that anatomical embedding potentiates sensory-motor integration. We find that signal spreading is faster from nodes associated with sensory transduction (sensors) to nodes associated with motor output (effectors). Signal propagation was accelerated if sensor nodes were activated simultaneously, suggesting a topologically mediated synergy among sensors. In addition, the organization of the network increases the likelihood of convergence of multiple cascades towards effector nodes, thereby facilitating integration prior to motor output. Moreover, effector nodes tend to coactivate more frequently than other pairs of nodes, suggesting an anatomically enhanced coordination of motor output. Altogether, our results show that the organization of the mesoscale Drosophila connectome imparts privileged, behaviorally relevant communication patterns among sensors and effectors, shaping their capacity to collectively integrate information.