Synthesizing aluminum particles towards controlling electrostatic discharge ignition sensitivity

Aluminum particles were synthesized with shell thicknesses ranging from 2.7 to 8.3 nm and a constant diameter of 95 nm. These fuel particles were combined with molybdenum trioxide particles and the electrostatic discharge (ESD) sensitivity of the mixture was measured. Results show ignition delay increased as the alumina shell thickness increased. These results correlated with electrical resistivity measurements of the mixture which increased with alumina concentration. A model was developed using COMSOL for ignition of a single Al particle. The ignition delay in the model was consistent with the experimental results suggesting that the primary ESD ignition mechanism is joule heating.     

Desensitizing nano powders to electrostatic discharge ignition

Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.     

Measurement of electrostatic discharge ignition risks from conductive components of Personal Protective Equipment

To assist with the development of a SUCAM document for PPE for safe use in explosive atmospheres, the authors have carried out measurements on metal items typically attached to PPE, using capacitance meters, charge sharing and charge transfer test methods. Capacitance was determined without spacers, and with spacers to simulate layers of clothing. Results indicate that the use of capacitance meters in this context may not provide complete information necessary for evaluation of ignition risks. Consideration should be given to specifying charge sharing or charge transfer methods. The results of small capacitance measurements should be considered to have considerable uncertainty.     

静放电电磁脉冲模拟装置

介绍了静电放电电磁脉冲（ESD EMP）的特性，研究了用ESD模拟器产生ESD EMP的方法，并给出了ESD EMP的时域波形和频谱。在研究ESD模拟器的基础上，首次通过ESD模拟器和GTEM室的结合，在GTEM室内产生了均匀的，重复性和线性好的ESD EMP。实验表明，用这种能够实验对静电放电电磁脉冲的实验室模拟，实验了人们用GTEM室产生ESD EMP的梦想。     

静电放电电磁脉冲模拟装置

 介绍了静电放电电磁脉冲（ESD EMP）的特性。研究了用ESD 模拟器产生ESD EMP的方法，并给出了ESD EMP的时域波形和频谱。在研究ESD模拟器的基础上，首次通过ESD模拟器和GTEM室的结合，在GTEM室内产生了均匀的、重复性和线性好的ESD EMP。实验表明，用这种装置能够实现对静电放电电磁脉冲的实验室模拟。实现了人们用GTEM室产生ESD EMP的梦想。     

Analysis and finite element simulation of electromagnetic heating in the nitride MOCVD reactor

Electromagnetic field distribution in the vertical metal organic chemical vapour deposition (MOCVD) reactor is simulated by using the finite element method (FEM). The effects of alternating current frequency, intensity, coil turn number and the distance between the coil turns on the distribution of the Joule heat are analysed separately, and their relations to the value of Joule heat are also investigated. The temperature distribution on the susceptor is also obtained. It is observed that the results of the simulation are in good agreement with previous measurements.     

静电放电火花产生的电磁场树枝模型

 静电放电火花产生的电磁脉冲会对电子系统的正常工作造成严重的干扰，甚至造成系统的损伤。利用时域有限差分法建立了静电放电火花产生的电磁场的数值模型，模型中充分考虑了放电电极上的静电荷对电场的影响。把由此模型放电计算的电磁场值与由此解析方法得到的场值进行了比较，结果吻合良好。由此可以用此模型来研究静电放电火花产生的电磁场与电子系统的能量耦合问题。     

接近速度对空气静电放电特性的影响

 通过理论分析和实验测量,研究了导体接近速度对空气放电的影响。理论计算了两导体相互接近时导体的自（互）电容系数、导体电势差、导体电势差随导体间的间隙（放电间隙）的变化率和导体电势差的时间变化率。实验研究了5 kV和10 kV放电电压下放电电流峰值和耦合电压峰-峰值随接近速度的变化关系。接近速度直接决定了空气击穿时导体电势差的时间变化率,同时也就决定了不同速度下的空气放电特性;接近速度影响了火花击穿的时间延迟,从而对空气放电产生了时间效应。     

Preparation of PVOH coatings with graphene nanoplatelets for electrostatic discharge protective packaging

This study investigated the use of graphene nanoplatelets (GNP) as a conductive filler for electrostatic discharge (ESD) protective packaging. Various weight concentrations of GNP were mixed and sonicated with polyvinyl alcohol (PVOH). The resulting polymer solution was applied as a coating to corrugated board in order to form an ESD packaging. Surface resistivity, mechanical strength and coating adhesion were then measured. The study found that the electrical percolation threshold of the PVOH/GNP coating is 9–13wt% GNP. GNP incorporated PVOH coatings with surface resistivity of 10³–10⁸ Ω/sq. generally meet all of ESD packaging requirements. The humidity strongly affects the surface resistivity of the coatings below the percolation threshold, but the change of the surface resistivity with humidity is less significant above the percolation threshold.     

Effect of Joule heating on the electroosmotic microvortex and dielectrophoretic particle separation controlled by local electric field

Dielectrophoresis (DEP) technology has become important application of microfluidic technology to manipulate particles. By using a local modulating electric field to control the combination of electroosmotic microvortices and DEP, our group proposed a device using a direct current (DC) electric field to achieve continuous particle separation. In this paper, the influence of the Joule heating effect on the continuous separation of particles is analyzed. Results show that the Joule heating effect is caused by the local electric field, and the Joule heating effect caused by adjusting the modulating voltage is more significant than that by driving voltage. Moreover, a non-uniform temperature distribution exists in the channel due to the Joule heating effect, and the temperature is the highest at the midpoint of the modulating electrodes. The channel flux can be enhanced, and the enhancement of both the channel flux and temperature is more obvious for a stronger Joule heating effect. In addition, the ability of the vortices to trap particles is enhanced since a larger DEP force is exerted on the particles with the Joule heating effect; and the ability of the vortex to capture particles is stronger with a stronger Joule heating effect. The separation efficiency can also be increased because perfect separation is achieved at a higher channel flux. Parameter optimization of the separation device, such as the convective heat transfer coefficient of the channel wall, the length of modulating electrode, and the width of the channel, is performed.     

静电波对磁化等离子体的共振加热的理论及数值模拟研究

利用多标度展开得到了更一般的静电波与磁化等离子体回旋运动间的共振条件；通过数值模拟证实了理论分析，发现分数频率同样可以产生共振加热；发现加热效果即使对于相同频率的波，也不是随驱动波的振幅单调增强，而是存在一些优势振幅，即在特定频率特定振幅下有特别好的加热效果. 关键词： 等离子体 共振加热 非线性动力学     

静电放电对功率肖特基二极管I-V及低频噪声特性的影响

本文基于人体放电模型分别对肖特基势垒二极管的阴极和阳极进行同一电压脉冲下的多次放电, 利用热电子发射理论、1/f噪声的迁移率涨落模型和白噪声理论, 分别深入研究静电放电损伤对器件I-V和低频噪声的影响. 结果表明, 静电放电作用于肖特基二极管阴极时损伤更严重, 噪声参量变化率更大. 随着放电次数的增加, 正向特性无变化, 反向电流总体增大, 偶有减小; 而正向和反向 1/f噪声均增大. 鉴于噪声与应力条件下器件内部产生的缺陷与损伤有关, 且更敏感, 故可将低频噪声特性用作肖特基二极管的静电放电损伤灵敏表征工具.     

Structure-dependent behaviors of diode-triggered silicon controlled rectifier under electrostatic discharge stress

The comprehensive understanding of the structure-dependent electrostatic discharge behaviors in a conventional diode-triggered silicon controlled rectifier(DTSCR) is presented in this paper. Combined with the device simulation, a mathematical model is built to get a more in-depth insight into this phenomenon. The theoretical studies are verified by the transmission-line-pulsing(TLP) test results of the modified DTSCR structure, which is realized in a 65-nm complementary metal–oxide–semiconductor(CMOS) process. The detailed analysis of the physical mechanism is used to provide predictions as the DTSCR-based protection scheme is required. In addition, a method is also presented to achieve the tradeoff between the leakage and trigger voltage in DTSCR.     

Electric ignition energy evaluation and the energy distribution structure of energy released in electrostatic discharge process

Ignition energy is one of the important parameters of flammable materials, and evaluating ignition energy precisely is essential to the safety of process industry and combustion science and technology. By using electric spark discharge test system, a series of electric spark discharge experiments were conducted with the capacitor-stored energy in the range of 10 J, 100 J, and 1000 J, respectively. The evaluation method for energy consumed by electric spark, wire, and switch during capacitor discharge process has been studied respectively. The resistance of wire, switch, and plasma between electrodes has been evaluated by different methods and an optimized evaluation method has been obtained. The electric energy consumed by wire, electric switch, and electric spark-induced plasma between electrodes were obtained and the energy structure of capacitor-released energy was analyzed. The dynamic process and the characteristic parameters(the maximum power, duration of discharge process) of electric spark discharge process have been analyzed. Experimental results showed that, electric spark-consumed energy only accounts for 8%–14% of the capacitor-released energy. With the increase of capacitor-released energy, the duration of discharge process becomes longer, and the energy of plasma accounts for more in the capacitor-released energy. The power of electric spark varies with time as a damped sinusoids function and the period and the maximum value increase with the capacitor-released energy.     

Controlling the electrostatic discharge ignition sensitivity of composite energetic materials using carbon nanotube additives

Powder energetic materials are highly sensitive to electrostatic discharge (ESD) ignition. This study shows that small concentrations of carbon nanotubes (CNT) added to the highly reactive mixture of aluminum and copper oxide (Al + CuO) significantly reduces ESD ignition sensitivity. CNT act as a conduit for electric energy, bypassing energy buildup and desensitizing the mixture to ESD ignition. The lowest CNT concentration needed to desensitize ignition is 3.8 vol.% corresponding to percolation corresponding to an electrical conductivity of 0.04 S/cm. Conversely, added CNT increased Al + CuO thermal ignition sensitivity to a hot wire igniter.     

粉体工业静电防护技术研究进展

粉体静电灾害涉及面广、危害大，开发合理的粉体静电防灾技术是国民经济发展过程中需要解决的热点问题之一．近年来，粉体静电测试研究方法、粉体静电起电与放电研究方法、粉体静电危险性评价方法、粉体静电危险性分级理论等研究工作取得了较好的研究成果．根据粉体静电现实危险性量化分析的结果而采取的粉体防静电灾害技术措施，为粉体工业生产提供了一定的安全保障．     

Electrical joule heating for the isolation of ZnO nanowire channel and subsequent high-performance 1D circuit integration

In this work, electrical Joule heating (J-H) was employed for the first time to electrically isolate ZnO nanowire FETs array for one dimensional (1D) logic applications without any physical and electrical damages. The electrical properties of the isolated nanowire FETs were found to be superior to non-isolated FETs came from the neighboring gate effect. Finally, we investigated ZnO nanowire-based NOT, NAND, and NOR logic gates with the J-H nanowire isolation technique. The isolated logic gates clearly show much lower output voltage off level than the non-isolated circuits thus resulting in more accurate and reliable 1D electronic applications.     

Electric-pulse-induced local conducting area and joule heating effect in VO2/Al2O3 films

We investigated the effect of an electric-pulse on the insulator–metal phase transition of VO₂/Al₂O₃ films using synchrotron-based infrared microspectroscopy. By monitoring the time-resolved optical response, we could demonstrate that local conducting areas are formed under the influence of the electric-pulse, and the Joule heat generated from the local current flow drives a consecutive thermal phase transition in the adjacent sample area.