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- 实验方案
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Mechanically Enhanced Electrical Conductivity of Polydimethylsiloxane-Based Composites by a Hot Embossing Process
摘要： Electrically conductive polymer composites are in high demand for modern technologies, however, the intrinsic brittleness of conducting conjugated polymers and the moderate electrical conductivity of engineering polymer/carbon composites have highly constrained their applications. In this work, super high electrical conductive polymer composites were produced by a novel hot embossing design. The polydimethylsiloxane (PDMS) composites containing short carbon fiber (SCF) exhibited an electrical percolation threshold at 0.45 wt % and reached a saturated electrical conductivity of 49 S/m at 8 wt % of SCF. When reducing the sample thickness from 1.0 to 0.1 mm by the hot embossing process, a compression-induced percolation threshold occurred at 0.3 wt %, while the electrical conductivity was further enhanced to 378 S/m at 8 wt % SCF. Furthermore, the addition of a second nanofiller of 1 wt %, such as carbon nanotube or conducting carbon black, further increased the electrical conductivity of the PDMS/SCF (8 wt %) composites to 909 S/m and 657 S/m, respectively. The synergy of the densified conducting filler network by the mechanical compression and the hierarchical micro-/nano-scale filler approach has realized super high electrically conductive, yet mechanically flexible, polymer composites for modern flexible electronics applications.
关键词： compression-induced percolation threshold,synergy,electrical conducting network,hybrid filler,forced assembly
更新于2025-09-23 15:22:29
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Rapid and non-invasive surface crack detection for pressed-panel products based on online image processing
摘要： Crack detection during the manufacturing process of pressed-panel products is an important aspect of quality management. Traditional approaches for crack detection of those products are subjective and expensive because they are usually performed by experienced human inspectors. Therefore, the development and implementation of an automated and accurate inspection system is required for the manufacturing process. In this article, a crack detection technique based on image processing is proposed that utilizes the images of panel products captured by a regular camera system. First, the binary panel object image is extracted from various backgrounds after considering the color factor. Edge lines are then generated from a binary image using a percolation process. Finally, crack detection and localization is performed with a unique edge-line evaluation. In order to demonstrate the capability of the proposed technique, lab-scale experiments were carried out with a thin aluminum plate. In addition, a test was performed with the panel images acquired at an actual press line. Experimental results show that the proposed technique could effectively detect panel cracks at an improved rate and speed. The experimental results also demonstrate that the proposed technique could be an extension of structural health monitoring frameworks into a new manufacturing application.
关键词： crack detection,image processing,signal processing,percolation,Non-contact sensing
更新于2025-09-23 15:22:29
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Edge Computing Enabled Unmanned Module Defect Detection and Diagnosis System for Large-scale Photovoltaic Plants
摘要： The network connectivity of sel?sh wireless networks (SeWNs) constituted by sel?sh nodes (SeNs) is investigated. The SeN’s degree of node-sel?shness (DeNS) is used for characterizing the effects of its energy resources and the bene?ts of the incentives provided for enhancing its transmission willingness. Furthermore, the SeNs’ signal to interference plus noise ratios are de?ned in terms of both their DeNSs and their interference factors. We then continue by quantifying the effect of node-sel?shness on the grade of network connectivity and derive both the upper and lower bounds of the critical DeNS. Explicitly, the network is deemed to be connected when the DeNS is below the lower bound and unconnected for a DeNS above the upper bound. This allows us to quantify the asymptotic critical DeNSs for our SeWNs. In addition, we develop an energy-conscious node-sel?shness model for characterizing the relationship between the SeN’s residual energy and its DeNS. Based on this model and on the asymptotic critical DeNS derived, the critical amount of residual energy required for maintaining a speci?c grade of network connectivity is determined, which is veri?ed by our simulation results.
关键词： node-sel?shness,Network connectivity,energy resource,percolation theory,sel?sh wireless network
更新于2025-09-23 15:21:01
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A Predictive Model for the Electrical Transport Within Nanowire Networks
摘要： Thin networks of high aspect ratio conductive nanowires can combine high electrical conductivity with excellent optical transparency, which has led to a widespread use of nanowires in transparent electrodes, transistors, sensors, and ?exible and stretchable conductors. Although the material and application aspects of conductive nanowire ?lms have been thoroughly explored, there is still no model which can relate fundamental physical quantities, like wire resistance, contact resistance and nanowire density, to the sheet resistance of the ?lm. Here we derive an analytical model for the electrical conduction within nanowire networks based on an analysis of the parallel resistor network. The model captures the transport characteristics and ?ts a wide range of experimental data, allowing for the determination of physical parameters and performance limiting factors, in sharp contrast to the commonly employed percolation theory. The model thus constitutes a useful tool with predictive power for the evaluation and optimization of nanowire networks in various applications.
关键词： nanowires,electrical transport,model,percolation,carbon nanotubes,nanowire network,silver nanowires
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE Industry Applications Society Annual Meeting - Baltimore, MD, USA (2019.9.29-2019.10.3)] 2019 IEEE Industry Applications Society Annual Meeting - High-Efficient High-Power-Factor Off-Line LED Driver based on Integrated Buck and Boost Converter
摘要： The network connectivity of sel?sh wireless networks (SeWNs) constituted by sel?sh nodes (SeNs) is investigated. The SeN’s degree of node-sel?shness (DeNS) is used for characterizing the effects of its energy resources and the bene?ts of the incentives provided for enhancing its transmission willingness. Furthermore, the SeNs’ signal to interference plus noise ratios are de?ned in terms of both their DeNSs and their interference factors. We then continue by quantifying the effect of node-sel?shness on the grade of network connectivity and derive both the upper and lower bounds of the critical DeNS. Explicitly, the network is deemed to be connected when the DeNS is below the lower bound and unconnected for a DeNS above the upper bound. This allows us to quantify the asymptotic critical DeNSs for our SeWNs. In addition, we develop an energy-conscious node-sel?shness model for characterizing the relationship between the SeN’s residual energy and its DeNS. Based on this model and on the asymptotic critical DeNS derived, the critical amount of residual energy required for maintaining a speci?c grade of network connectivity is determined, which is veri?ed by our simulation results.
关键词： node-sel?shness,Network connectivity,energy resource,percolation theory,sel?sh wireless network
更新于2025-09-23 15:19:57
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Finely depressed dielectric loss and conductivity achieved in high-kappa stannic oxide/polymer nanocomposites from surfactant-assisted electric percolation
摘要： During past decades, both of interface polarization and electric percolation mechanisms have been found to have a significant influence on the dielectric and conductive properties of polymer based nanocomposites bearing electrically conducting nanoparticles. Although the significantly elevated high dielectric constant of composites has gained great success, the finely balanced high dielectric constant, depressed dielectric loss and low conductivity have been faced with a huge challenge. Instead of the high-cost organic modification onto the surfaces of inorganic conductive nanofiller, in current work, a small quantity of polyvinylpyrrolidone surfactant was introduced to prepare the ternary polymer based nanocomposite films bearing stannic oxide nanoparticles. Their dielectric and conductive performances were compared with that of the corresponding binary composites without bearing that surfactant. The positive influence of that surfactant on the finely balanced high comprehensive electric properties of composites namely high dielectric constant and depressed loss/conductivity was confirmed due to the improving of interface compatibility and depressing of interface air voids. The ternary nanocomposite bearing 10 vol% filler could have a dielectric constant of ca. 175, loss of ca. 0.35 and conductivity of ca. 1.8 × 10?5 S cm?1 at 1 kHz under 1 V bias voltage. This work might open the door to the large-scale fabrication of promising composite dielectrics materials by facilely introducing the third surfactant component.
关键词： surfactant,stannic oxide,dielectric properties,polymer nanocomposites,electric percolation
更新于2025-09-23 15:19:57
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[ACM Press the 14th IEEE/ACM International Symposium - Athens, Greece (2018.07.17-2018.07.19)] Proceedings of the 14th IEEE/ACM International Symposium on Nanoscale Architectures - NANOARCH '18 - Programmable Molecular-Nanoparticle Multi-junction Networks for Logic Operations
摘要： We propose and investigate a nanoscale multi-junction network architecture that can be configured on-flight to perform Boolean logic functions at room temperature. The device exploits the electronic properties of randomly deposited molecule-interconnected metal nanoparticles, which act collectively as strongly nonlinear single-electron transistors. Disorder is being incorporated in the modeling of their electrical behavior and the collective response of interacting nano-components is being rationalized. The non-optimized energy consumption of the synaptic grid for a "then-if" logical computation is in the range of few aJ.
关键词： percolation,nonlinear single electron transistors,multi-junction networks,botton-up designless networks,nanoelectrodes,Molecular-Nanoparticle hybrids,Boolean logic operations
更新于2025-09-19 17:15:36
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Improvement of 2.79 um laser performance on the LD side-pumped GYSGG/Er,Pr:GYSGG bonding rod with concave end-faces
摘要： The melting of crystals is one of the commonest and most general phase transition phenomena, however, the mechanism of crystal melting is not understood enough, and more experimental measurements and explorations are still needed. The mechanical spectra of propylene carbonate and 1,3-propanediol during the crystal melting processes are measured by the reed vibration mechanical spectroscopy for liquids (RMS-L) for the first time. The experimental results show that, with the increasing temperature, the real part of complex Young modulus decreases slowly first, and then quickly drops to zero, meanwhile, its imaginary part increases slowly at first, then goes up and drops quickly to zero, showing a peak of internal friction. Preliminary analyses indicate that both the real and imaginary parts can present some characteristics of the melting process, such as the transition from the liquid regions disconnected to the connected, that from the crystal regions connected to the disconnected and so on. In addition, the results show that the melting rate per unit volume of crystalline phase versus temperature satisfies the Arrhenius relation at the initial stage of melting and deviates from this relation as the temperature increases to a certain value. Therefore, the RMS-L will provide an effective supplement for the further study of melting.
关键词： mechanical spectroscopy,percolation,complex Young modulus,crystal melting
更新于2025-09-19 17:13:59
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Graphene/polyphenylene sulfide composites for tailorable negative permittivity media by plasmonic oscillation
摘要： Composites with negative permittivity have drawn much attentions for novel capacitance design and electromagnetic shielding applications. Herein, polyphenylene sulfide (PPS) matrix composites filled with graphene were prepared by hot-pressing for tailorable negative permittivity media. Electrical percolation occurred as graphene content increasing and the conduction mechanism changed into free electron model. Graphene/PPS composites with tailorable negative permittivity properties were realized, resulting from the plasmonic oscillation of free electrons in composites exceeding percolation threshold. The regulation mechanism of negative permittivity in this random composite was clarified, and the obtained tailorable negative permittivity media could be novel candidates for various electromagnetic applications.
关键词： Percolation,Polymeric composites,Dielectrics,Negative permittivity
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Plug-and-Play Generation and Manipulation of Squeezing on Chip
摘要： We propose a novel graphic method to enable the analysis of the field-effect transistor (FET) threshold voltage variation (cid:2)Vth due to random telegraph signals in a percolative channel. First, through technology computer-aided design simulation with no percolation, both a minimum (cid:2)Vth and a critical curve in a mloc ? σloc plot are produced. The former constitutes a statistical distribution far away from the conventional log-normal one. In the latter, mloc and σloc are the mean and the standard deviation, respectively, of a well-known normal variable in Mueller–Schulz’s percolation theory. The critical mloc ? σloc curve divides the plot into the allowed region and the forbidden region and will go down with increasing gate size. Then, (cid:2)Vth contours in the allowed region are graphically created. While applying to existing experimental (cid:2)Vth statistical distributions of SiON- and high-k metal gate (HKMG)-scaled FETs, resulting paired mloc and σloc at high (cid:2)Vth remain intact, regardless of gate size or gate stack type. This means that the underlying percolation patterns resemble each other, due to the same manufacturing process used. However, if these paired mloc and σloc fall in the forbidden region, it is the critical mloc ? σloc curve dominating. Application to bias and temperature instability statistical data in literature is straightforwardly well done.
关键词： percolation,technology computer-aided design (TCAD),Bias and temperature instability (BTI),trap,random telegraph signals (RTSs),field-effect transistors (FETs)
更新于2025-09-16 10:30:52