scholarly journals The Mechanism of Layer Stacked Clamping (LSC) for Polishing Ultra-Thin Sapphire Wafer

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 759
Author(s):  
Zhixiang Chen ◽  
Linlin Cao ◽  
Julong Yuan ◽  
Binghai Lyu ◽  
Wei Hang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Capillary Force ◽  
Adhesion Force ◽  
Fundamental Problem ◽  
Fractal Theory ◽  
Droplet Volume ◽  
Sapphire Wafer ◽  
Normal Adhesion ◽  
Rough Surface Contact ◽  
Polishing Efficiency

Double-sides polishing technology has the advantages of high flatness and parallelism, and high polishing efficiency. It is the preferred polishing method for the preparation of ultra-thin sapphire wafer. However, the clamping method is a fundamental problem which is currently difficult to solve. In this paper, a layer stacked clamping (LSC) method of ultra-thin sapphire wafer which was used on double-sides processing was proposed and the clamping mechanism of layer stacked clamping (LSC) was studied. Based on the rough surface contact model of fractal theory, combining the theory of van der Waals force and capillary force, the adhesion model of the rough surfaces was constructed, and the reliability of the model was verified through experiments. Research has found that after displacement between the two surfaces the main force of the adhesion force is capillary force. The capillary force decreases with the increasing of surface roughness, droplet volume, and contact angle. For an ultra-thin sapphire wafer with a diameter of 50.8 mm and a thickness of 0.17 mm, more than 1.4 N of normal adhesion force can be generated through the LSC method. Through the double-sides polishing experiment using the LSC method, an ultra-thin sapphire wafer with an average surface roughness (Ra) of 1.52 nm and a flatness (PV) of 0.968 μm was obtained.

scholarly journals Assessing the Functional Properties of TiZr Nanotubular Structures for Biomedical Applications, through Nano-Scratch Tests and Adhesion Force Maps

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 900
Author(s):  
Maria Vardaki ◽  
Aida Pantazi ◽  
Ioana Demetrescu ◽  
Marius Enachescu
Keyword(s):  
Surface Roughness ◽  
Functional Properties ◽  
Bacterial Adhesion ◽  
Biomedical Applications ◽  
Adhesion Force ◽  
Roughness Parameters ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Mean ◽  
Scratch Tests

In this work we present the results of a functional properties assessment via Atomic Force Microscopy (AFM)-based surface morphology, surface roughness, nano-scratch tests and adhesion force maps of TiZr-based nanotubular structures. The nanostructures have been electrochemically prepared in a glycerin + 15 vol.% H2O + 0.2 M NH4F electrolyte. The AFM topography images confirmed the successful preparation of the nanotubular coatings. The Root Mean Square (RMS) and average (Ra) roughness parameters increased after anodizing, while the mean adhesion force value decreased. The prepared nanocoatings exhibited a smaller mean scratch hardness value compared to the un-coated TiZr. However, the mean hardness (H) values of the coatings highlight their potential in having reliable mechanical resistances, which along with the significant increase of the surface roughness parameters, which could help in improving the osseointegration, and also with the important decrease of the mean adhesion force, which could lead to a reduction in bacterial adhesion, are providing the nanostructures with a great potential to be used as a better alternative for Ti implants in dentistry.

Contact Analysis of a Smooth Ball on an Anisotropic Rough Surface

1994 ◽  
Vol 116 (4) ◽  
pp. 850-859 ◽  
Author(s):  
C. Y. Poon ◽  
R. S. Sayles
Keyword(s):  
Surface Roughness ◽  
Rough Surface ◽  
Stochastic Approach ◽  
Contact Analysis ◽  
Asperity Contact ◽  
Correlation Lengths ◽  
Real Contact ◽  
Rough Surface Contact ◽  
Contact Pressures ◽  
Contact Spots

The effects of surface roughness and waviness upon the real contact areas, gaps between contact spots, and asperity contact pressures were studied. The distribution of real areas, gaps, and contact pressures are presented for different surface roughness, σ and correlation lengths, β*. The load-area relationship is compared to Bush’s model of strongly anisotropic rough surface contact using a stochastic approach.

Capillary Forces Described by Effective Contact Angle Distributions via Simulations of the Centrifuge Technique

MRS Advances ◽  
2016 ◽  
Vol 1 (31) ◽  
pp. 2237-2245
Author(s):  
Myles Thomas ◽  
Elizabeth Krenek ◽  
Stephen Beaudoin
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Smooth Surface ◽  
Adhesion Force ◽  
Capillary Forces ◽  
Angle Distribution ◽  
Particle Adhesion ◽  
Multiple Factors ◽  
Effective Contact ◽  
Condensed Moisture

ABSTRACTUnderstanding particle adhesion is vital to any industry where particulate systems are involved. There are multiple factors that affect the strength of the adhesion force, including the physical properties of the interacting materials and the system conditions. Surface roughness on the particles and the surfaces to which they adhere, including roughness at the nanoscale, is critically important to the adhesion force. The focus of this work is on the capillary force that dominates the adhesion whenever condensed moisture is present. Theoretical capillary forces were calculated for smooth particles adhered to smooth and rough surfaces. Simulations of the classical centrifuge technique used to describe particle adhesion to surfaces were performed based on these forces. A model was developed to describe the adhesion of the particles to the rough surface in terms of the adhesion to a smooth surface and an ‘effective’ contact angle distribution.

Particle detachment due to wheel rotation

2020 ◽  
pp. 1420326X2093516
Author(s):  
Jinwei Song ◽  
Hua Qian ◽  
Xiaohong Zheng
Keyword(s):  
Surface Roughness ◽  
Silicon Dioxide ◽  
Adhesion Force ◽  
Aluminium Oxide ◽  
Theoretical Models ◽  
Wheel Speed ◽  
Spherical Particles ◽  
Wheel Surface ◽  
Particle Detachment ◽  
Oxide Particles

Particle detachment induced by a rotating wheel was investigated theoretically and experimentally. The developed theoretical models were used to reveal how the particle detaches from a wheel surface to the surrounding air. The corresponding experiments were carried out to validate proposed models. Two groups of spherical particles were considered, i.e. silicon dioxide and aluminium oxide particles. Different forces and force moments acting on individual particles were analysed. The criteria for the rolling detachment of particles were considered. The detachment diameters under various conditions were calculated. The results show that the particle detachment was dominated by the removal and resistant forces acting on particles, including the gravity force, adhesion force, hydrodynamic force and centrifugal force. Different relevant parameters can affect particle detachment through these forces, including surface roughness, wheel speed, particle size and properties. A higher wheel speed, larger particle sizes and higher wheel surface roughness were shown to have a conducive influence on particle detachment. The resistant and removal force moments could be affected by the particle properties at the same time; therefore, the detachment diameters of the aluminium oxide particles are similar to those of silicon dioxide. This study can contribute towards the estimation of particle emissions from vehicles.

scholarly journals Selected Physicochemical Properties of Diamond Like Carbon (DLC) Coating on Ti-13Nb-13Zr Alloy Used for Blood Contacting Implants

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5077
Author(s):  
Magdalena Antonowicz ◽  
Roksana Kurpanik ◽  
Witold Walke ◽  
Marcin Basiaga ◽  
Jozef Sondor ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Physicochemical Properties ◽  
Fundamental Problem ◽  
Circulatory System ◽  
Titanium Implants ◽  
Diamond Like Carbon ◽  
Dlc Coating ◽  
13Zr Alloy ◽  
Artificial Plasma ◽  
Modification Of Titanium

Despite high interest in the issues of hemocompatibility of titanium implants, particularly those made of the Ti-13Nb-13Zr alloy, the applied methods of surface modification still do not always guarantee the physicochemical properties required for their safe operation. The factors that reduce the efficiency of the application of titanium alloys in the treatment of conditions of the cardiovascular system include blood coagulation and fibrous proliferation within the vessel’s internal walls. They result from their surfaces’ physicochemical properties not being fully adapted to the specifics of the circulatory system. Until now, the generation and development mechanics of these adverse processes are not fully known. Thus, the fundamental problem in this work is to determine the correlation between the physicochemical properties of the diamond like carbon (DLC) coating (shaped by the technological conditions of the process) applied onto the Ti-13Nb-13Zr alloy designed for contact with blood and its hemocompatibility. In the paper, microscopic metallographic, surface roughness, wettability, free surface energy, hardness, coating adhesion to the substrate, impendence, and potentiodynamic studies in artificial plasma were carried out. The surface layer with the DLC coating ensures the required surface roughness and hydrophobic character and sufficient pitting corrosion resistance in artificial plasma. On the other hand, the proposed CrN interlayer results in better adhesion of the coating to the Ti-13Nb-13Zr alloy. This type of coating is an alternative to the modification of titanium alloy surfaces using various elements to improve the blood environment’s hemocompatibility.

scholarly journals Optimization of the Polishing Efficiency and Torque by Using Taguchi Method and ANOVA in Robotic Polishing

2020 ◽  
Vol 10 (3) ◽  
pp. 824
Author(s):  
Imran Mohsin ◽  
Kai He ◽  
Zheng Li ◽  
Feifei Zhang ◽  
Ruxu Du
Keyword(s):  
Surface Roughness ◽  
Taguchi Method ◽  
Signal To Noise Ratio ◽  
Surface Friction ◽  
Surface Finishing ◽  
Polished Surface ◽  
Machining Parameters ◽  
Regression Equations ◽  
Polishing Force ◽  
Polishing Efficiency

Surface finishing and polishing are important quality assurance processes in many manufacturing industries. A polished surface (low surface roughness) is linked with many useful properties other than providing an appealing gloss to the product, such as surface friction, electrical and chemical resistance, thermal conductivity, reflection, and product life. All these properties require an efficient polishing system working with the best machining parameters. This study analyzed the effects of the different input polishing parameters on the polishing efficiency and torque in the robotic polishing system for the circular-shaped workpieces (such as ring, cylinder, sphere, cone, etc.) by using the Taguchi method and analysis of variance (ANOVA). A customized rotatory passive gripper is designed to hold the watch bezel during polishing. Under the design of experiments (DOE) technique, Taguchi’s L 18 array is selected to find the optimized process parameters for polishing efficiency (based on surface roughness) and torque. Experimental results with the statistical analysis by signal-to-noise ratio and ANOVA (95% confidence level) confirms that the polishing force and tool speed are the most influencing parameter for polishing efficiency in the system. Linear regression equations are modeled for the polishing efficiency and torque. Finally, a confirmation test is conducted for the validation of the experimentation results against actual results.

scholarly journals Adhesion force mapping on wood by atomic force microscopy: influence of surface roughness and tip geometry

2016 ◽  
Vol 3 (10) ◽  
pp. 160248 ◽  
Author(s):  
X. Jin ◽  
B. Kasal
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Wood Surface ◽  
Adhesion Force ◽  
Data Interpretation ◽  
Natural Fibre ◽  
Force Distribution ◽  
Adhesion Forces ◽  
Force Microscopy ◽  
Atomic Force

This study attempts to address the interpretation of atomic force microscopy (AFM) adhesion force measurements conducted on the heterogeneous rough surface of wood and natural fibre materials. The influences of wood surface roughness, tip geometry and wear on the adhesion force distribution are examined by cyclic measurements conducted on wood surface under dry inert conditions. It was found that both the variation of tip and surface roughness of wood can widen the distribution of adhesion forces, which are essential for data interpretation. When a common Si AFM tip with nanometre size is used, the influence of tip wear can be significant. Therefore, control experiments should take the sequence of measurements into consideration, e.g. repeated experiments with used tip. In comparison, colloidal tips provide highly reproducible results. Similar average values but different distributions are shown for the adhesion measured on two major components of wood surface (cell wall and lumen). Evidence supports the hypothesis that the difference of the adhesion force distribution on these two locations was mainly induced by their surface roughness.

scholarly journals The anti-soiling performance of highly reflective superhydrophobic nanoparticle-textured mirrors

Nanoscale ◽  
2018 ◽  
Vol 10 (30) ◽  
pp. 14600-14612 ◽  
Author(s):  
Gyoung Gug Jang ◽  
D. Barton Smith ◽  
Frederick Alyious List ◽  
Dominc F. Lee ◽  
Anton V. Ievlev ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Adhesion Force ◽  
Dust Particles

Highly transparent, superhydrophobic nanoparticle-textured coatings with engineered surface roughness significantly decrease the adhesion force of dust particles on the surface, resulting in soil and dust repellent performance.

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