PFPE Modified Silicon Nano-Textured Surfaces for Adhesion and Friction Reduction

2008 ◽  
Author(s):  
Ying Song ◽  
Hengyu Wang ◽  
Min Zou
Keyword(s):  
Amorphous Silicon ◽  
Silicon Surface ◽  
Surface Hydrophobicity ◽  
Friction Reduction ◽  
New Technique ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Hydrophobic Surfaces ◽  
A New Technique ◽  
Induced Crystallization

This paper reports a new technique of producing hydrophobic surfaces with WCA as high as 147°. This technique consists of first generating nano-textures on a silicon surface via aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) and then applying perfluoropolyether (PFPE) on the nano-textured surface (NTS). The resulting PFPE-modified NTS showed significant improvement on both surface hydrophobicity and tribological performances compared to a PFPE-modified smooth silicon surface.

scholarly journals Wettability on Different Surfaces

2020 ◽  
Author(s):  
Yeeli Kelvii Kwok
Keyword(s):  
Contact Angle ◽  
Textured Surface ◽  
Original Material ◽  
Textured Surfaces ◽  
Hydrophobic Surfaces ◽  
Hydrophilic Surfaces ◽  
Young's Equation

Wettability has been explored for 100 years since it is described by Young’s equation in 1805. It is all known that hydrophilicity means contact angle (θ), θ < 90°; hydrophobicity means contact angle (θ), θ > 90°. The utilization of both hydrophilic surfaces and hydrophobic surfaces has also been achieved in both academic and practical perspectives. In order to understand the wettability of a droplet distributed on the textured surfaces, the relevant models are reviewed along with understanding the formation of contact angle and how it is affected by the roughness of the textured surface aiming to obtain the required surface without considering whether the original material is hydrophilic or hydrophobic.

Hydrophobic Surfaces Prepared by Aluminum-Induced Crystallization of Amorphous Silicon

2007 ◽  
Author(s):  
Ying Song ◽  
Rahul Premachandran Nair ◽  
Min Zou
Keyword(s):  
Amorphous Silicon ◽  
Annealing Temperature ◽  
Textured Surfaces ◽  
Surface Wetting ◽  
Water Contact ◽  
Annealing Conditions ◽  
Wetting Property ◽  
Percentage Area ◽  
Induced Crystallization ◽  
Aluminum Induced Crystallization

This paper reports fabrication and understanding of hydrophobic silicon nano-textured surfaces produced by aluminum-induced crystallization (AIC) of amorphous silicon (a-Si). In this study, the effects of annealing temperature and duration on surface topography and wetting property were investigated. The results showed that surface wetting property directly correlates with the percentage area coverage by the nano-textures, which in turn was determined by the annealing conditions. The largest water contact angle (WCA) obtained from this research is 137°.

Friction Reduction by Micro-Textured Surfaces in Lubrication

2018 ◽  
Vol 12 (4) ◽  
pp. 603-610 ◽  
Author(s):  
Yue Sun ◽  
Keita Shimada ◽  
Shaolin Xu ◽  
Masayoshi Mizutani ◽  
Tsunemoto Kuriyagawa ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Contact Surface ◽  
Friction Reduction ◽  
Experimental Investigations ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Diamond Cutting ◽  
Tribological Tests ◽  
Sliding Direction

Experimental investigations were carried out to verify if the friction reduction in lubrication can be expanded by a textured surface with sawtooth riblets. Sawtooth riblets were formed by ultraprecision diamond cutting, with a ridge angle of about 60°–90° and height of about 20–50 μm on the contact surface. Six types of textured surfaces with different ridge angles, heights, and sliding directions were tested and compared with the untextured surface. The tribological tests were conducted by a flat-on-flat tribometer in lubrication. The effects of the ridge angle, height, and relative sliding direction on the friction coefficient in lubrication were reported.

scholarly journals Surface Texture Influences on the Running-in Behavior and Friction Reduction

2018 ◽  
Vol 159 ◽  
pp. 02017
Author(s):  
Zhouyong Hou ◽  
Tomomi Honda
Keyword(s):  
Surface Texture ◽  
Internal Combustion Engines ◽  
Friction And Wear ◽  
Fuel Efficiency ◽  
Surface Profile ◽  
Friction Reduction ◽  
Profile Measurement ◽  
Textured Surface ◽  
Combustion Engines ◽  
Textured Surfaces

For improving automobile fuel efficiency, the internal combustion engines must be required to reduce the friction and wear. Changing viscosity of lubricant and surface pressure could succeed, but the seizure is easy to happen in engines. However, the surface texture can solve those problems. The running-in behavior affects friction and wear on whole combustion engines. If the running-in is not carefully designed, catastrophic accident can happen. This experiment investigates that the running-in behavior is influenced by textured surfaces and the tested materials are the cast iron and the different area ratio of dimple of aluminum alloy combination. The friction coefficient and the number and size of wear particles are measured by the friction sensor and particle counter. After the tests, the worn surfaces are measured through using surface profile measurement systems, and some significant phenomena are observed and analyzed. The textured surface verifies good consequence and tribological advantages.

Doping glow-discharge amorphous silicon by metal coevaporation

1987 ◽  
Vol 65 (8) ◽  
pp. 1027-1029 ◽  
Author(s):  
G. Perluzzo ◽  
C. Aktik ◽  
J. F. Currie ◽  
S. Poulin-Dandurand ◽  
A. Yelon ◽  
...  
Keyword(s):  
Glow Discharge ◽  
Amorphous Silicon ◽  
Mass Spectroscopy ◽  
Thermal Evaporation ◽  
New Technique ◽  
A New Technique ◽  
And Control ◽  
Further Development ◽  
Monitor And Control

We report here on the further development of a new technique for doping plasma-deposited amorphous silicon by thermal evaporation of metal into the plasma from which the film is grown. We show that the de bias applied to the substrate has an important effect on the incorporation of the metal into the film, and on the doping efficiency. We also report on our efforts to monitor and control the evaporation by mass spectroscopy.

Analysis of Fill Factor Losses in a-Si and a-SiGe Alloy Solar Cells Using a New Technique

1995 ◽  
Vol 377 ◽  
Author(s):  
A. Banerjee ◽  
X. Xu ◽  
J. Yang ◽  
S. Guha
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Fill Factor ◽  
New Technique ◽  
Light Illumination ◽  
Single Junction ◽  
Current Collection ◽  
Sige Alloy ◽  
Back Reflectors ◽  
A New Technique

ABSTRACTA new technique to diagnose fill factor losses occurring in single-junction amorphous silicon (a-Si) alloy based nip solar cells has been explored. The method consists of the measurements of the fill factor of the device under blue and red light illumination and the current-collection loss obtained from the ratio of the quantum efficiency versus wavelength spectra at zero and reverse bias. Normally, the losses are higher at low and high wavelengths. It has been observed that there is a strong correlation between the values of the blue and red fill factors and the current collection losses at the pli interfaces and the bulk of the i-layer, respectively. The losses have been attributed to back diffusion of carriers at the pli interface and to the bulk of the i-Layer. There is a sensitive dependence between these losses and the texture of the substrate: textured substrates lead to higher losses compared to specular substrates. The technique has been used successfully to enhance the values of the red, blue, and AM 1.5 fill factors of both a-Si and amorphous silicon-germanium (a-SiGe) alloy single-junction cells on back reflectors by the optimization of device fabrication parameters. The optimized cells on textured back reflectors exhibit reduced losses. The paper presents an analysis of the experimental results.

Fabrication of Superhydrophilic Surfaces by Aluminum-Induced Crystallization of Amorphous Silicon

2008 ◽  
Author(s):  
Kenneth Kollias ◽  
Hengyu Wang ◽  
Min Zou
Keyword(s):  
Contact Angle ◽  
Amorphous Silicon ◽  
Textured Surfaces ◽  
Water Contact ◽  
Glass Substrates ◽  
Solid Substrates ◽  
Glass Surfaces ◽  
First Time ◽  
Induced Crystallization ◽  
Aluminum Induced Crystallization

Aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) was, for the first time, used to produce textured surfaces to increase the wettability of solid substrates. It was found that glass substrates textured by AIC of a-Si technique exhibit highly stable superhydrophilic property. The water contact angle (WCA) of the textured glass surfaces became less than 5° in 0.5 second immediately after the AIC of a-process and remained less than 10° in 1 second even after the samples were stored in air for 192 hours.

Adhesion/Stiction and Friction Studies of Nano/Micro-Textured Surfaces Produced by Crystallization of Amorphous Silicon

2005 ◽  
Author(s):  
Hengyu Wang ◽  
Li Cai ◽  
Dehua Yang ◽  
Thomas Wyrobek ◽  
Min Zou
Keyword(s):  
Low Temperature ◽  
Amorphous Silicon ◽  
Surface Texturing ◽  
Chemical Vapor ◽  
Contact Forces ◽  
New Method ◽  
Textured Surfaces ◽  
Normal Contact ◽  
Chemical Vapor Deposited ◽  
Induced Crystallization

This paper reports a new method of nano/micro surface-texturing and the results of systematic studies of adhesion/stiction and friction properties on the textured surfaces produced by this method. Nano/micro-textured surfaces with various roughnesses were produced by low temperature aluminum-induced crystallization of plasma enhanced chemical vapor deposited (PECVD) amorphous silicon. Adhesion/stiction experiments on these nano/microtextured and non-textured surfaces were performed using two diamond tips under predefined displacement profiles with different maximum indentation displacements. Friction experiments on the textured and non-textured surfaces were conducted using the same tips under various normal contact forces. The adhesion/stiction forces and coefficients of friction (COF) of the textured surfaces were found to be much smaller than those of non-textured surfaces.

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