Experimental Study on Electromechanical Failure of Dielectric Elastomer Actuator

2015 ◽  
Author(s):  
Xuejing Liu ◽  
Shuhai Jia ◽  
Hualing Chen ◽  
Bo Li ◽  
Yu Xing
Keyword(s):  
Breakdown Voltage ◽  
Failure Modes ◽  
Dielectric Breakdown ◽  
Electrical Breakdown ◽  
Dielectric Elastomer ◽  
Theoretical Explanation ◽  
Special Focus ◽  
Stress Effect ◽  
Deformation State ◽  
Boundary Stress

The dielectric elastomer (DE) is an insulating membrane with extra-ordinary properties which can meet various electromechanical failures during the actuation. In the current work, we measured breakdown voltage in DE membrane with special focus on the varying boundary stress during the actuation process. The boundary stress tuned deformation state, causing the membrane to deform out-of-plane before breakdown. A theoretical model is presented, involving the strain-stiffening effect in material and boundary stress effect in geometry, to estimate the dielectric breakdown voltage. The results agree with the experiments. Then, another set of experimental investigation is conducted to study the voltage-induced wrinkling of DE membrane. Steady wrinkles, without an accompany of electrical breakdown are attained and three different failure modes of DE membrane are classified into a phase chart. Finally, a qualitative theoretical explanation on wrinkling mechanism of DE membrane is presented and verified by experimental observations.

Computational Model and Design of the Soft Tunable Lens Actuated by Dielectric Elastomer

2020 ◽  
Vol 87 (7) ◽  
Author(s):  
Jinrong Li ◽  
Xiongfei Lv ◽  
Liwu Liu ◽  
Yanju Liu ◽  
Jinsong Leng
Keyword(s):  
Computational Model ◽  
Failure Modes ◽  
Electrical Breakdown ◽  
Focal Length ◽  
Length Change ◽  
Dielectric Elastomer ◽  
Compact Structure ◽  
Active Film ◽  
Tunable Lenses ◽  
Tunable Lens

Abstract Inspired by the accommodation mechanism of the human eye, several soft tunable lenses have been fabricated and demonstrated the capability of controllable focus tuning. This paper presents a computational model of a dielectric elastomer-based soft tunable lens with a compact structure that is composed of a lens frame, two soft films, and the optically transparent fluid enclosed inside. The two soft films, respectively, serve as the active film and passive film. The active film is a dielectric elastomer film and can be coated with the annular electrode or circular electrode. The deformation of the lenses with both electrode configurations can all be formulated by a boundary value problem with different boundary conditions and be solved as the initial value problem using the shooting method. Two common failure modes of loss of tension and electrical breakdown are considered in the calculation of the lens. The computational results can well fit the experimental data. The focus tuning performances as well as the distributions of stretches, stresses, and electric field in the active films of the lenses with two different electrode configurations are compared. The influences of several parameters on the performances of the lenses are discussed, such that the tunable lens can be designed to have maximum focal length change or to be optimized based on different application requirements.

Effect of Water on Electrical Properties of Refined, Bleached, and Deodorized Palm Oil (RBDPO) as Electrical Insulating Material

2013 ◽  
Vol 64 (4) ◽  
Author(s):  
Nazera Ismail ◽  
Yanuar Z. Arief ◽  
Zuraimy Adzis ◽  
Shakira A. Azli ◽  
Abdul Azim A. Jamil ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Breakdown Voltage ◽  
Palm Oil ◽  
Pour Point ◽  
Electrical Breakdown ◽  
Dissipation Factor ◽  
Mineral Oil ◽  
Flash Point ◽  
Effect Of Water ◽  
Insulating Liquid

This paper describes the properties of refined, bleached, deodorized palm oil (RBDPO) as having the potential to be used as insulating liquid. There are several important properties such as electrical breakdown, dielectric dissipation factor, specific gravity, flash point, viscosity and pour point of RBDPO that was measured and compared to commercial mineral oil which is largely in current use as insulating liquid in power transformers. Experimental results of the electrical properties revealed that the average breakdown voltage of the RBDPO sample, without the addition of water at room temperature, is 13.368 kV. The result also revealed that due to effect of water, the breakdown voltage is lower than that of commercial mineral oil (Hyrax). However, the flash point and the pour point of RBDPO is very high compared to mineral oil thus giving it advantageous possibility to be used safely as insulating liquid. The results showed that RBDPO is greatly influenced by water, causing the breakdown voltage to decrease and the dissipation factor to increase; this is attributable to the high amounts of dissolved water.

A Study of Oxide Etch Angle of Edge Termination Field Plate for Fabrication of SiC SBD

2017 ◽  
Vol 730 ◽  
pp. 102-105
Author(s):  
Ey Goo Kang
Keyword(s):  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Power Semiconductor ◽  
Field Plate ◽  
Edge Termination ◽  
Power Semiconductor Devices ◽  
Silicon Materials ◽  
Generation Power

The silicon carbide (SiC) material is being spotlighted as a next-generation power semiconductor material due to the characteristic limitations of the existing silicon materials. SiC has a wider band gap, higher breakdown voltage, higher thermal conductivity, and higher saturation electron mobility than Si. However, actual SiC SBDs exhibit a lower dielectric breakdown voltage than the theoretical breakdown voltage that causes the electric field concentration, a phenomenon that occurs on the edge of the contact surface as in the conventional power semiconductor devices. In this paper, we designed an edge termination structure using a field plate structure through oxide etch angle control, and optimized the structure to obtain a high breakdown voltage. The experiment results indicated that oxide etch angle was 45° when the breakdown voltage characteristics of the SiC SBD were optimized and a breakdown voltage of 681V was obtained.

A study of the effect of temperature on the dielectric breakdown and lifetime of polyethylene materials under applied DC voltages at the nanoscale

2020 ◽  
Vol 89 (3) ◽  
pp. 30401
Author(s):  
Imed Boukhris ◽  
Imen Kebaili ◽  
Halima Ibrahim El Saeedy ◽  
Ezzeddine Belgaroui ◽  
Ali Kallel
Keyword(s):  
Temporal Evolution ◽  
Dielectric Breakdown ◽  
Electrical Breakdown ◽  
Effect Of Temperature ◽  
External Current ◽  
Abrupt Increase ◽  
Conduction Current ◽  
Dc Voltage ◽  
Breakdown Phenomenon ◽  
Simulation Results

The reported simulation results could be considered as one of the firsts modeling of the effect of temperature on the electrical breakdown phenomenon in polyethylene nanoscale. The breakdown begins with an abrupt increase of the external current density without a subsequent saturation. Our results show that the increase of temperature at a constant applied DC voltage leads to a breakdown and to a decrease of the insulator's lifetime. These outcomes are strongly linked to the injection of free charges into the sample and to the temporal evolution of the conduction current.

Influence of cathode material type on the electrical breakdown behaviors of DC discharge

2020 ◽  
Vol 98 (8) ◽  
pp. 726-731
Author(s):  
F. Diab ◽  
W.H. Gaber ◽  
M.E. Abdel-kader ◽  
B.A. Soliman ◽  
M.A. Abd Al-Halim
Keyword(s):  
Cathode Material ◽  
Work Function ◽  
Breakdown Voltage ◽  
Cathode Materials ◽  
Electrical Breakdown ◽  
Ionization Efficiency ◽  
Parallel Plates ◽  
Maximum Value ◽  
Dc Discharge ◽  
Work Functions

Paschen curves were studied using different cathode materials such as magnesium, zinc, and carbon graphite by discharge in argon gas of a pressure range between 0.08 and 3 Torr using a parallel plates configuration. The first and second Townsend coefficients (α and γ, respectively) and the ionization efficiency (η) of different cathode materials were deduced from Paschen curves as a function of the reduced field (E/P). The minimum breakdown voltage was found to be about 242 V for Mg material, which has the lowest work function, while carbon graphite has a higher breakdown voltage of 283 V due to its higher work function. The second coefficient γ was increased as a function of E/P and has higher values for materials of lower work functions, and a similar trend of γ is obtained as a function of the ion mean energy. On the other hand, the first coefficient α has a reverse behavior with both E/P and the work function of the cathode materials compared with the second coefficient. The ionization efficiency of the three cathode materials is identical, as η depends only on the gas properties and not the cathode material. η has a maximum value of about 0.025 V−1 for an E/P of about 185 Vcm−1Torr−1, corresponding to the maximum ionizing ability of electrons. The validation of the breakdown results has been confirmed by conferring with other published experimental measurements.

Analysis and Design of a Robust RF MEMS Switch

2012 ◽  
Author(s):  
Ibrahim Chamseddine ◽  
Hadi Kasab ◽  
Maya Antoun ◽  
Tawfiq Dahdah ◽  
Mohammed Mirhi ◽  
...  
Keyword(s):  
Failure Modes ◽  
Rf Mems ◽  
Dielectric Breakdown ◽  
Rf Switch ◽  
Switching Speed ◽  
Analysis And Design ◽  
Electrostatically Actuated ◽  
Mems Switch ◽  
Switching Performance ◽  
Contact Adhesion

A MEMS RF switch is expected to undergo 10 billion switching cycles before failure. Until complete physical explanation for these failure modes that include contact adhesion, damping effects, stiction, increases in resistance with time, dielectric breakdown, and electron trapping is fully established, the technology’s numerous advantages cannot be harvested reliably and efficiently. This paper investigates prospective solutions to problems in switch designs by proposing a new design for the switch. We consider the new design from different perspectives: dynamic, electric, fluidic, etc. It is billed to overcome the difficulties and involves the implementation of liquid metal contact electrostatically actuated to ensure the same switching performance, with prolonged life span, and robust switching speed.

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