Dielectric Breakdown and Failure of Ferroelectric Films as the Dielectric for Electrowetting Systems

2016 ◽  
Vol 697 ◽  
pp. 231-234 ◽  
Author(s):  
Wei Qiang Wang ◽  
Jia Qi Niu ◽  
Zhen Kun Xie ◽  
Zhen Xing Yue
Keyword(s):  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Charge Trapping ◽  
Ferroelectric Thin Film ◽  
Ferroelectric Film ◽  
Dc Voltage ◽  
Voltage Polarity ◽  
Ferroelectric Layer ◽  
Voltage Frequency

In this paper, we study the electrical properties and breakdown phenomena of PZT ferroelectric thin film in electrowetting systems. The experimental results indicate that irreversible charge trapping occurred with repeated voltage actuation, resulting in contact angle relaxation and reduction of the ferroelectric film breakdown strength. The breakdown voltage depends on DC voltage polarity, and this polarity dependence was found to be related to the thickness of the ferroelectric layer. When AC voltage was applied, the breakdown voltage increased directly with voltage frequency. These phenomena are interpreted in terms of electrochemical reactions at the liquid/solid interface, an empirical model was used to estimate the amount of trapped charge in the ferroelectric film.

Polarity Effect and Dielectric Breakdown of Composite Ferroelectric Films as the Dielectric for Electrowetting Systems

2018 ◽  
Vol 281 ◽  
pp. 598-603 ◽  
Author(s):  
Wei Qiang Wang ◽  
Yan Su
Keyword(s):  
Thin Film ◽  
Electrical Properties ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Ferroelectric Thin Film ◽  
Ferroelectric Film ◽  
Ferroelectric Films ◽  
Dc Voltage ◽  
Voltage Polarity ◽  
Voltage Frequency

In this paper, we study the electrical properties and breakdown phenomena of BaTiO3/Teflon composite ferroelectric thin film in electrowetting systems. The experimental results showed that the electrowetting effect and the breakdown voltage depend on DC voltage polarity, and this polarity dependence is closely related to the thickness of the ferroelectric film. Under AC voltages, the breakdown voltage increased directly with voltage frequency. These results are useful for designing reliable EWOD devices with low operation voltages and high robustness.

scholarly journals Streamer evolution arrest governed amplified AC breakdown strength of graphene and CNT colloids

2019 ◽  
Vol 85 (3) ◽  
pp. 30402 ◽  
Author(s):  
Purbarun Dhar ◽  
Ankur Chattopadhyay ◽  
Lakshmi Sirisha Maganti ◽  
Anilakkad Raman Harikrishnan
Keyword(s):  
Mathematical Model ◽  
Carbon Nanotubes ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Effective Electron ◽  
Dielectric Breakdown Strength ◽  
Mineral Oils ◽  
Two Parameter ◽  
Fundamental Mechanism

The present paper explores the concept of improving the AC dielectric breakdown strength of insulating mineral oils by the addition of graphene or carbon nanotubes (CNTs) to form stable dispersions. Experimental observations of graphene and CNT nano-oils show that not only improved average breakdown voltage, but also significantly improved reliability and survival probabilities of the oils under AC high voltage stressing is achieved. Improvement of the tune of ∼70–80% in the AC breakdown voltage of the oils has been obtained. The study examines the reliability of such nano-colloids using a two-parameter Weibull distribution and the oils show greatly augmented electric field bearing capacity. The fundamental mechanism responsible for such observed outcomes is reasoned to be delayed streamer development and reduced streamer growth rates due to effective electron scavenging. A mathematical model based on the principles of electron scavenging is proposed to quantify the amount of electrons scavenged by the nanostructures.

scholarly journals Design of an AC Driving Waveform Based on Characteristics of Electrowetting Stability for Electrowetting Displays

2020 ◽  
Vol 8 ◽  
Author(s):  
Linwei Liu ◽  
Zhuoyu Wu ◽  
Li Wang ◽  
Taiyuan Zhang ◽  
Wei Li ◽  
...  
Keyword(s):  
Response Time ◽  
Indium Tin Oxide ◽  
Pulse Width Modulation ◽  
Charge Trapping ◽  
Driving Voltage ◽  
Reverse Voltage ◽  
Dc Voltage ◽  
Voltage Curve ◽  
Voltage Frequency ◽  
Driving Waveform

In traditional electrowetting display (EWD) drivers, direct current (DC) voltage and pulse width modulation are often used, which easily caused an electrowetting charge trapping phenomenon in a hydrophobic insulating layer. Therefore, the driving voltage must be increased for driving EWDs, and oil backflow cannot be solved. Aqueous solutions are often used as polar liquids for EWDs, and the reverse voltage of alternating current (AC) driving can cause chemical reactions between water and indium tin oxide (ITO). So, a driving waveform was proposed, which included a DC waveform and an AC waveform, to separately drive EWDs for oil rupture and open state. Firstly, a DC waveform was used when the oil was broken, and the response time was reduced by designing the DC voltage and duration. Secondly, an AC waveform was used when the oil required to be stable. Oil backflow could be suppressed by the AC waveform. The main parameters of AC waveform include reverse voltage, frequency and duty cycle. The reverse voltage of EWDs could be obtained by voltammetry. The frequency could be obtained by analyzing the rising and falling edges of the capacitance voltage curve. The experimental results showed that the proposed waveform can effectively suppress oil backflow and shorten the response time. The response time was about 86% lower than the conventional driving waveforms, and oil backflow was about 72% slower than the DC driving waveform.

Polyimide Film for Generator Winding

2017 ◽  
pp. 15-56
Keyword(s):  
Electrical Properties ◽  
Water Absorption ◽  
Surface Charge ◽  
Breakdown Voltage ◽  
Dielectric Breakdown ◽  
Partial Discharge ◽  
Polyimide Film ◽  
Polyimide Films ◽  
Direct Fluorination ◽  
Voltage Frequency

Polyimide film is widely used in different areas due to its brilliant chemical and electrical properties. This chapter discusses effect of direct fluorination on surface charge and surface partial discharge of polyimide films. The influences of different fluorination time and voltage frequency are studied. The trap properties of polyimide film are analyzed. It is clear that the fluorination has changed the micro structure of the sample so that the trap property and the dissipation time are different. Further research focuses on the effects of water absorption on surface charge and dielectric breakdown of nanocomposite. The polyimide/Al2O3 film is selected as sample and the relation between water absorption and surface charge and breakdown voltage is discussed.

scholarly journals Dielectric Breakdown Strength and Energy Storage Density of CCTO-ZBS Electroceramic

2020 ◽  
Vol 596 ◽  
pp. 012006
Author(s):  
Muhammad Qusyairie Saari ◽  
Julie Juliewatty Mohamed ◽  
Muhammad Azwadi Sulaiman ◽  
Mohd Fariz Abd Rahman ◽  
Zainal Arifin Ahmad ◽  
...  
Keyword(s):  
Energy Storage ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Energy Storage Density ◽  
Dielectric Breakdown Strength ◽  
Storage Density

scholarly journals Construction of a Three-Dimensional BaTiO3 Network for Enhanced Permittivity and Energy Storage of PVDF Composites

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3585
Author(s):  
Xueqing Bi ◽  
Lujia Yang ◽  
Zhen Wang ◽  
Yanhu Zhan ◽  
Shuangshuang Wang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Polyvinylidene Fluoride ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Sol Gel ◽  
Three Dimensional ◽  
Low Dielectric ◽  
Energy Storage Properties ◽  
Discharge Energy Density ◽  
Pure Pvdf

Three-dimensional BaTiO3 (3D BT)/polyvinylidene fluoride (PVDF) composite dielectrics were fabricated by inversely introducing PVDF solution into a continuous 3D BT network, which was simply constructed via the sol-gel method using a cleanroom wiper as a template. The effect of the 3D BT microstructure and content on the dielectric and energy storage properties of the composites were explored. The results showed that 3D BT with a well-connected continuous network and moderate grain sizes could be easily obtained by calcining a barium source containing a wiper template at 1100 °C for 3 h. The as-fabricated 3D BT/PVDF composites with 21.1 wt% content of 3D BT (3DBT–2) exhibited the best comprehensive dielectric and energy storage performances. An enhanced dielectric constant of 25.3 at 100 Hz, which was 2.8 times higher than that of pure PVDF and 1.4 times superior to the conventional nano–BT/PVDF 25 wt% system, was achieved in addition with a low dielectric loss of 0.057 and a moderate dielectric breakdown strength of 73.8 kV·mm−1. In addition, the composite of 3DBT–2 exhibited the highest discharge energy density of 1.6 × 10−3 J·cm−3 under 3 kV·mm−1, which was nearly 4.5 times higher than that of neat PVDF.

scholarly journals Improvement of DC Breakdown Strength of the Epoxy/POSS Nanocomposite by Tailoring Interfacial Electron Trap Characteristics

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1298
Author(s):  
Farooq Aslam ◽  
Zhen Li ◽  
Guanghao Qu ◽  
Yang Feng ◽  
Shijun Li ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Breakdown Voltage ◽  
Breakdown Strength ◽  
Deep Level ◽  
Simulation Method ◽  
Neat Epoxy ◽  
Interfacial Region ◽  
Chemical Calculation ◽  
Oligomeric Silsesquioxane ◽  
Underlying Risk

To date, breakdown voltage is an underlying risk to the epoxy-based electrical high voltage (HV) equipment. To improve the breakdown strength of epoxy resin and to explore the formation of charge traps, in this study, two types of polyhedral oligomeric silsesquioxane (POSS) fillers are doped into epoxy resin. The breakdown voltage test is performed to investigate the breakdown strength of neat epoxy and epoxy/POSS composites. Electron traps that play an important role in breakdown strength are characterized by thermally stimulated depolarized current (TSDC) measurement. A quantum chemical calculation tool identifies the source of traps. It is found that adding octa-glycidyl POSS (OG-POSS) to epoxy enhances the breakdown strength than that of neat epoxy and epoxycyclohexyl POSS (ECH-POSS) incorporated epoxy. Moreover, side groups of OG-POSS possess higher electron affinity (EA) and large electronegativity that introduces deep-level traps into epoxy resin and restrain the electron transport. In this work, the origin of traps has been investigated by the simulation method. It is revealed that the functional properties of POSS side group can tailor an extensive network of deep traps in the interfacial region with epoxy and enhance the breakdown strength of the epoxy/POSS nanocomposite.

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