Driving Scheme Optimization for Electrowetting Displays Based on Contact Angle Hysteresis to Achieve Precise Gray-Scales

As a new display technology, electrowetting display (EWD) has many excellent display characteristics, such as paper-like, low power consumption, quick response and full color. These characteristics make EWD devices very suitable for portable devices. However, the gray-scale distortion caused by the contact angle hysteresis of EWDs seriously affects the accuracy of gray-scale display. To improve this phenomenon, the hysteresis curve of an EWD panel was studied according to the motion characteristics of advancing contact angle and receding contact angle of oil in a pixel. Then, a driving scheme for EWDs using alternating current (AC) voltage instead of direct current (DC) voltage was proposed in this paper. And the advantages and disadvantages of the driving scheme at different AC frequencies from 90 to 2,700 Hz were analyzed through experiments. According to the stability of aperture ratio in EWDs, a 470 Hz AC driving scheme was determined. Experimental results showed that the aperture ratio distortion of EWDs could be reduced from 35.82 to 5.97%, which significantly improved the display performance of pixel units.

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The Surface Modification with Fluorocarbon Thin Films for the Prevention of Stiction in Mems

MRS Proceedings ◽

10.1557/proc-518-143 ◽

1998 ◽

Vol 518 ◽

Cited By ~ 5

Author(s):

Sang-Ho Lee ◽

Myong-Jong Kwon ◽

Jin-Goo Park ◽

Yong-Kweon Kim ◽

Hyung-Jae Shin

Keyword(s):

Contact Angle ◽

Contact Angle Hysteresis ◽

Contact Angles ◽

Fluorocarbon Films ◽

Perfluorodecanoic Acid ◽

Large Hysteresis ◽

Static Contact ◽

Receding Contact ◽

Highly Hydrophobic ◽

Receding Contact Angle

AbstractHighly hydrophobic fluorocarbon films were prepared by the vapor phase (VP) deposition method in a vacuum chamber using both liquid (3M's FC40, FC722) and solid sources (perfluorodecanoic acid (CF3(CF2)8COOH), perfluorododecane (C12F26)) on Al, Si and oxide coated wafers. The highest static contact angles of water were measured on films deposited on aluminum substrate. But relatively lower contact angles were obtained on the films on Si and oxide wafers. The advancing and receding contact angle analysis using a captive drop method showed a large contact angle hysteresis (ΔH) on the VP deposited fluorocarbon films. AFM study showed poor film coverage on the surface with large hysteresis. FTIR-ATR analysis positively revealed the stretching band of CF2 groups on the VP deposited substrates. The thermal stability of films was measured at 150°C in air and nitrogen atmospheres as a function of time. The rapid decrease of contact angles was observed on VP deposited FC and PFDA films in air. However, no decrease of contact angle on them was observed in N2.

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Tensiometric studies on wetting. I. Some effects of surface roughness (theoretical)

Canadian Journal of Chemistry ◽

10.1139/v81-290 ◽

1981 ◽

Vol 59 (13) ◽

pp. 1954-1961 ◽

Cited By ~ 23

Author(s):

Erdal Bayramli ◽

Theodore G. M. van de Ven ◽

Stanley G. Mason

Keyword(s):

Surface Roughness ◽

Contact Angle ◽

Contact Angle Hysteresis ◽

Solid Surfaces ◽

Surface Slopes ◽

Receding Contact ◽

Receding Contact Angle ◽

Wetting Hysteresis ◽

Non Equilibrium ◽

Roughness Size

The effect of roughness on the wettability of an axisymmetric cylinder is investigated theoretically by making use of equilibrium meniscus shapes on solid surfaces analogously to previous studies for drops on horizontal surfaces. Employing circumferential sinusoidal and saw-toothed grooved structure, and using mechanistic arguments, one can explain wetting hysteresis, the formation of composite surfaces, and the presence of non-equilibrium jumps during contact line motion.On unidirectionally random surfaces the maximum surface slopes mainly determine the value of the advancing, and the minimum slopes of the receding contact angle. These effects of surface slopes diminish with decreasing roughness size. Diminishing roughness size also gives rise to numerous small non-equilibrium jumps imposed upon larger jumps during wetting. The contact angle hysteresis is found to show a nearly linear relationship with the spread in the distribution of solid surface slopes.

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Contact Angle Hysteresis – Advantages and Disadvantages: A Critical Review

10.1002/9781119846703.ch3 ◽

2021 ◽

pp. 47-67

Author(s):

Andrew Terhemen Tyowua ◽

Stephen Gbaoron Yiase

Keyword(s):

Contact Angle ◽

Critical Review ◽

Contact Angle Hysteresis ◽

Advantages And Disadvantages

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Contact angle hysteresis on plasma treated polyethylene terephthalate

e-Polymers ◽

10.1515/epoly.2012.12.1.479 ◽

2012 ◽

Vol 12 (1) ◽

Author(s):

Marcela Bachurová ◽

Jakub Wiener

Keyword(s):

Contact Angle ◽

Polyethylene Terephthalate ◽

Photoelectron Spectroscopy ◽

Contact Angle Hysteresis ◽

Surface Wetting ◽

Time Intervals ◽

Receding Contact ◽

Surface Dielectric Barrier Discharge ◽

Receding Contact Angle ◽

Modification Of The Surface

AbstractKnowledge of contact angle hysteresis is important to the understanding of surface wettability and to controlling further surface wetting behaviour. The wettability can be affected by surface modification. This study is a look on surfaces modified by the usage of plasma. We describe the effect of plasma treatments on contact angle hysteresis by the use of Diffuse Coplanar Surface Dielectric Barrier Discharge (DCSBD). Modification of the surface was achieved using textile made from polyethylene terephthalate (PET). Results have shown that both advancing and receding contact angle were significantly reduced by the process. The contact angle hysteresis was decreased after the plasma treatment as was observed by measurement taken at various time intervals and this fact correspond with introduction of functional groups detected by X - ray photoelectron spectroscopy (XPS).

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Mechanism of Water Infiltration and Defiltration through ZSM-5 Zeolite: Heating and Sodium Chloride Concentration Effect

Journal of Nanomaterials ◽

10.1155/2013/249369 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 7

Author(s):

Yueting Sun ◽

Jun Xu ◽

Yibing Li ◽

Xiaoqing Xu ◽

Cheng Liu ◽

...

Keyword(s):

Contact Angle ◽

Solid Phase ◽

Contact Angle Hysteresis ◽

Chloride Concentration ◽

Dissipation Function ◽

Water Infiltration ◽

Nacl Concentration ◽

Liquid Behavior ◽

Pretreatment Temperature ◽

Receding Contact Angle

Hydrophobic nanoporous material and wetting liquid together comprise a system with promising energy related applications. The mechanism of the interaction between liquid and solid phase is not fully explored. In this paper, based on the quasistatic compression experiments on investigating the mechanical behavior of ZSM-5 zeolite/NaCl solution system, the effects of two key parameters, that is, the pretreatment temperature of ZSM-5 zeolite and NaCl concentration, are parametrically and quantitatively investigated based on Laplace-Washburn equation. Results show that both pretreatment temperature and NaCl concentration raise the infiltration pressure and NaCl can also promote defiltration. The advancing contact and receding contact angle of zeolite-NaCl-air system increase with both pretreatment temperature and NaCl concentration, and the contact angle hysteresis decreases with NaCl concentration. Results may provide fundamental explanation to the nanoconfined liquid behavior and liquid-solid interaction, thus, to smartly control the mechanical properties of the liquid spring and bumpers for energy dissipation function.

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Contact Angle Hysteresis – Advantages and Disadvantages: A Critical Review

Reviews of Adhesion and Adhesives ◽

10.7569/raa.2020.097302 ◽

2020 ◽

Vol 8 (1) ◽

pp. 47-67

Author(s):

Andrew Terhemen Tyowua ◽

Stephen Gbaoron Yiase

Keyword(s):

Contact Angle ◽

Contact Angle Hysteresis ◽

Theoretical Models ◽

Contact Angles ◽

Solid Surfaces ◽

Advantages And Disadvantages ◽

Volatile Liquid ◽

Receding Contact ◽

Rain Drops ◽

The Difference

The existence of contact angle hysteresis – the difference between the values of the advancing and receding contact angles – is evident in nature (e.g. sticking of rain drops to car windscreens and window panes) and many industrial processes (e.g. surface coating, spraying, and dyeing of fabrics). This phenomenon is often viewed as a nuisance, but it is advantageous in many processes including dip and spin coating, spraying, and painting. With the early theoretical framework of Thomas Young, Robert Wenzel, and A. B. D. Cassie and S. Baxter, describing the wettability of solid surfaces and by extension contact angle, contact angle hysteresis has been deeply investigated. We review here the various ways of measuring contact angle and, consequently, contact angle hysteresis as well as related theoretical models. The successes and limitations of these models are highlighted. We conclude with the advantages and disadvantages of contact angle hysteresis whose presence in many processes is often considered as a nuisance, especially when "coffee stain" forms from the evaporation of a volatile liquid drop containing nonvolatile components.

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