Surface Texture Design Research Articles

Design and implementation of an integrated surface texture information system for design, manufacture and measurement

The optimized design and reliable measurement of surface texture are essential to guarantee the functional performance of a geometric product. Current support tools are however often limited in functionality, integrity and efficiency. In this paper, an integrated surface texture information system for design, manufacture and measurement, called “CatSurf”, has been designed and developed, which aims to facilitate rapid and flexible manufacturing requirements. A category theory based knowledge acquisition and knowledge representation mechanism has been devised to retrieve and organize knowledge from various Geometrical Product Specifications (GPS) documents in surface texture. Two modules (for profile and areal surface texture) each with five components are developed in the CatSurf. It also focuses on integrating the surface texture information into a Computer-aided Technology (CAx) framework. Two test cases demonstrate design process of specifications for the profile and areal surface texture in AutoCAD and SolidWorks environments respectively.

Surface Textures and Friction Control in Microforming

Tribological surface textures are considered in this paper as a non-traditional friction control solution for microforming. Textured pads fabrication techniques are first evaluated and load-controlled micro-embossing is chosen as the optimal method to produce repeatable textured patterns on metallic pads. Using tribometer experiments and finite element simulations of dry contact between untextured and textured surfaces for pressure levels representative of microforming conditions, it is shown that there are competing mechanisms creating a sinusoidal-like friction reduction behavior when surface textures are present. Ultimately, it is concluded that a proper design of surface textures and loading conditions can be used for friction reduction in microforming.

Influence of Geometric Shapes on the Hydrodynamic Lubrication of a Partially Textured Slider With Micro-Grooves

The effect of partial surface texturing in the form of parabolic grooves, rectangular grooves, and triangular grooves on the hydrodynamic pressure is investigated in the present work. The dimensionless hydrodynamic pressure generated by the partial surface texturing is obtained by the multigrid method. The effect of the texturing parameters on the dimensionless average pressure is analyzed for a given set of operating parameters. The results indicate that the geometric shape, area density, groove depth, and orientation of the grooves have an obvious influence on the hydrodynamic pressure. However, the groove width has little effect on the dimensionless average pressure. The results of the present work demonstrate that surface texturing design is very important to generate additional hydrodynamic pressure according to the operating parameters of the mechanical components.

Design principles for the area density of dimple patterns

Increasing interest has been paid to surface texturing in order to improve tribological properties of sliding surfaces. Currently, the patterns of micro-dimples have attracted more attention since such closed texture cells are supposed to generate additional hydrodynamic pressure easily. It has been proven that the area density of the dimple pattern is a critical parameter for hydrodynamic pressure generation. However, the optimal values of area density obtained by theoretical models are usually different to that obtained from experiments, which show material dependence. In order to understand the design principles of the area density for mixed lubrication regime, a brief review on the studies related to the area density issue of dimple patterns is carried out; the phenomena during contacting and sliding are analyzed numerically in this paper. It is found that the stress concentration and deformation will occur on the contacting and sliding area, and influence the tribological properties of the textured surface significantly depending on the area density and material properties. These negative influences should be considered carefully during surface texture design.

Toward a Rational Design of Surface Textures Promoting Endothelialization

The safe integration of cardiovascular devices requires the sustainable coverage of their luminal surface by endothelial cells (ECs). The engineering of active surface textures has the potential to coordinate cellular adhesion and migration under the action of hemodynamic forces. We define a paradigm to rationally design textures maximizing EC activities as a function of the applied stresses. This is based on harnessing the adhesions established by ECs through fine-tuning of the vertical extend of the underlying surface nanotopography.

Physical essence of the multibody contact-sliding at atomic scale

Investigation the multibody contact-sliding occurred at atomic discrete contact spot will play an important role in determine the origin of tribology behavior and evaluates the micro-mechanical property of nanomaterials and thus optimizing the design of surface texture. This paper carries out large scale parallel molecular dynamics simulation on contact-sliding at atomic scale to uncover the special physical essence. The research shows that some kind of force field exists between nanodot pair and the interaction can be expressed by the linear combination of exponential function while the effective interaction distance limited in 1 angstrom for nanodot with several tens of nanometer diameter. The variation tendency about the interaction force between nanodot array is almost the same between nanodot pairs and thus the interaction between two nanodot array can be characterized by parallel mechanical spring. Multibody effect which dominates the interaction between atoms or molecules will gradually diminish with the increasing of length scales.

Modelling of thin-film silicon solar cells

Computer modelling has become increasingly important in the design and optimization of surface textures that are used in thin-film solar cells to manipulate scattering of light. Light scattering at rough interfaces together with efficient back reflector is a standard approach to enhance absorption of light in the absorber layers of thin-film silicon solar cells. Substrates with randomly textured surface are commonly used to introduce rough interfaces into solar cells. Scalar scattering theory was used to describe light scattering at random nano-textured interfaces and to optimize random texture in single junction solar cells. Recently, substrates with periodic surface features have been investigated as an alternative to randomly surface-textured substrates. Three-dimensional Maxwell equation solvers were used to analyse and optimize such periodic textures when embedded in single and multi-junction solar cells. In both random and periodic cases, opto-electrical modelling was employed to assess the spectral response, to evaluate optical losses and to simulate current density–voltage characteristic.

Marketing Strategies of Herbal Cosmetic Products: Thai and Imported Products

This research investigated the factors that influence the marketing strategies of herbal cosmetic products in Thailand by comparison between Thai and imported product where the imported products are manufactured from Australia and U.S.A. This study is both quantitative and qualitative research. The facial herbal cosmetics products in this study were moisturizer, whitening lotion, cream, power, toner, make up cleansing mask, cleansing oil, soap bar, and anti-aging lotions. Finding from the study found that the marketing strategy of Thai herbal cosmetic products have the 4Ps;Product strategy by improving the quality of products, research and development for launching the new products to the market, creating beauty packaging and new product launch attracts the market’s attention. Price strategy using cash discount to increase consumer’s purchase motive. Place strategy using department stores as the main distribution channels, distribution channels are direct sales with catalogs, counter sales in department store and beauty showrooms. Promotion strategy using integrated marketing communication for maintaining brand image, television advertisement, radio advertisement, cabal advertisement, booth exhibition, beauty school, website, face to face marketing and male beauty instructor to attract the women customers. Marketing strategy of imported products; Products strategies are concerned with the odor, color, physical appearance of products and the penetration characteristic of products. The strategies promote the imported products by introducing the product e.g. the product is a blend of herbs, the most effective skin care for healthy, revitalized skin and natural extract that contains active ingredients with high technology to manufacture the cosmetic product that performs a specific action to penetrate deep into the skin. The smooth odor and color of the imported products are the important purchasing decision factor. Physical appearance of products; non greasy, non oily helps absorbs quickly into skin and help smooth the skin surface texture and packaging design, color, size and shape, play a role in purchasing decisions. Packaging has to possess the strength to make eye-catching packaging that helps make the most window of opportunity in pristine conditions, brand, logo/slogan as a way to facilitate their purchasing decision; the image of the brand has all the criteria value, quality reliability trust, intangible and delivers benefits to the consumers. Price strategy is heavily differentiated due to the branding then imported herbal cosmetic products offering lower priced luxury products. The lower prices could also boost sales e.g. smaller sizes of some products, such as 50 ml and 30 ml bottles of products, which is normally sold in 100 ml bottles then smaller bottles are selling better than regular size ones, Place strategy; purchasing convenience from the Internet to virtual presence e.g. Website, direct mail, social media enhancing the brand’s image. The site also uses Face book page by constantly updating content photos, videos, information about events, YouTube, twitter as platforms to keep customers up to date on new episodes and development. Promotion strategies using advertisement, television advertisement

Optimal Design of Surface Texture in Parallel Thrust Bearings

Surface textures of fan-shaped grooves of axisymmetrical distribution are designed on one of the parallel thrust bearing surfaces to improve the hydrodynamic lubrication performance of the bearing.In order to optimize the groove parameters(including the groove number,depth and area ratio),a regressive formula of the bearing load carrying capacity is obtained,based on the calculation results of the load carrying capacity by solving Reynolds equation under various combinations of bearing inner and outer diameters,rotation speed,lubricant viscosity,bearing clearance as well as the groove parameters.A formula of the bearing friction coefficient is derived using the regressive formula of the load carrying capacity.Based on these formulae,the optimal groove parameters are found under the four different kinds of constraints and optimization goals: Given the bearing clearance,requiring the maximal load carrying capacity or minimal friction coefficient;given the load carrying capacity,requiring the maximal bearing clearance or minimal friction coefficient.Furthermore,the validity of the optimal design is confirmed by comparing the load carrying capacity,bearing clearance and friction coefficient calculated by the regressive formulae with the full simulation results of Reynolds equation.Friction experiments are carried out on three surface textures of fan-shaped grooves with different groove numbers and depths.It is found that the trend of the calculated friction coefficient is the same as that of the experimental one,and the optimal results of the groove parameters are credible.

Optimal Design of Surface Texture in Parallel Thrust Bearings

Optimal Design of Surface Texture in Parallel Thrust Bearings

Hydrodynamic Lubrication of Conformal Contacting Surfaces With Parabolic Grooves

The effect of surface texturing in the form of parabolic grooves on the hydrodynamic lubrication properties is investigated in this paper. Numerical simulation of the pressure distribution of lubricant between a textured slider and a smooth, moving slider has been performed. The evaluation criterion of hydrodynamic effect of dimensionless average pressure is calculated and presented with the variation of minimum film thickness, groove width, groove depth, spacing and orientation angle. Optimum values of geometrical parameters such as the dimensionless groove depth, spacing and orientation angle are obtained which correspond to maximum average pressure. It is also noted that the average pressure increases monotonically with increasing groove width. The results show that the hydrodynamic effect can be improved by employing optimized surface texturing design.

A mechanical system to predict wet grip potential of pavements

A precise friction model is essential for the prediction of tyre wet grip performance and optimization of pavement surface texture design. A mechanical system for predicting the wet grip potential of asphalt pavement was systematically presented using an extended rubber material model by a time step integration scheme. This analytical approach was transferred to a 2D numerical multi-body system consisting of interconnected masses, coupling spring and elementary rubber element of a generalized Maxwell model of rubber tyre tread. The system consists of two basic modules with the same program structure and algorithm, considering the frequency-, temperature-, and strain-dependency behaviors of the complex dynamic modulus of rubber element. The dependence of penetration depth and friction coefficient on the velocity was simulated and validated. It can be concluded that this system can be used for predicting the wet grip potential of asphalt pavements.

Three‐Week Loading for Baha BI‐300 Implant System

Objective: Loading of titanium craniofacial implants is dependent upon osseointegration, the bonding of titanium oxide and bone. The purpose of this study seeks to determine the safety of early loading of the Baha BI-300 implant system (Cochlear Limited, Englewood, Colorado), which has been modified with novel surface texture and geometric design. Method: This prospective multi-institutional study follows implant stability as determined by clinical evaluation and resonance frequency analysis (RFA) at implantation, 1, 3, 6, 12, and 24 weeks postopative, in 20 patients who underwent single-stage implantation and exteriorization of the BI-300. The processor was loaded at 3 weeks postoperative. Results: Implant stability and the incidence of implant loss was compared with patients loaded at 6 weeks and the traditional 12 weeks postoperative. Our preliminary results confirm implant stability at 3 weeks postoperative. No increase in implant loss or postoperative complications were encountered as a result of the early loading. Conclusion: Three-week loading of the BI-300 implant did not result in any failure of osseointegration. Earlier activation of the external processor with earlier hearing rehabilitation resulted in improved patient satisfaction.

Optimization-based design of surface textures for thin-film Si solar cells

We numerically investigate the light-absorption behavior of thin-film silicon for normal-incident light, using surface textures to enhance absorption. We consider a variety of texture designs, such as simple periodic gratings and commercial random textures, and examine arbitrary irregular periodic textures designed by multi-parameter optimization. Deep and high-index-contrast textures exhibit strong anisotropic scattering that is outside the regime of validity of the Lambertian models commonly used to describe texture-induced absorption enhancement for normal incidence. Over a 900-1100 nm wavelength range, our optimized surface texture in two dimensions (2D) enhances absorption by a factor of 2.7 πn, considerably larger than the original πn Lambertian result and exceeding by almost 50% a recent generalization of Lambertian model for periodic structures in finite spectral range. However, the πn Lambertian limit still applies for isotropic incident light, and our structure obeys this limit when averaged over all the angles. Therefore, our design can be thought of optimizing the angle/enhancement tradeoff for periodic textures.

An unambiguous expression method of the surface texture

The current specification and verification of surface texture in international standards are considered to be too theoretical, complex and over-elaborate for industry. A functional approach that completely expresses the complicated surface texture knowledge for designers and engineers is often nonexistent on the shop floor. Based on Geometrical Product Specification (GPS) philosophy, this paper proposes an unambiguous expression schema of surface texture. The surface texture knowledge in design, manufacture and measurement is based on the general GPS matrix and structured by a categorical object model. Explicit specification and verification processes and the mapping between them are presented. The ultimate goal is to improve the collaboration and bridge the knowledge gap between design, manufacture and measurement of surface texture to reduce product development lead time and improve product quality and performance.

Model-based virtual surface texturing for concentrated conformal-contact lubrication

A model-based virtual texturing approach has been developed and applied to design, generate, ‘test’, and evaluate textured surfaces through numerical simulations. A series of studies on the numerical generation and performance evaluation of textured surfaces in a lubricated concentrated contact has been conducted, which includes (a) numerical generation of a large variety of textures considering possible geometric imperfections that exist in reality due to tooling design considerations and fabrication errors; (b) determination of texture depth, size, and area density; (c) texture distribution pattern selection; (d) bottom shape comparison and design optimization; (e) investigation of the influence of surface relative motion; (f) prediction of performance deviation caused by texture shape imperfections; and (g) evaluation of the effect of originally machined roughness. The present study was conducted using the deterministic mixed elastohydrodynamic lubrication (EHL) model recently developed, modified, and validated, which appears to be useful for surface texture design based on comparative performance evaluation in a wide range of operating conditions.

Fractal Geometry Surface Modeling and Measurement for Musical Cymbal Surface Texture Design and Rapid Manufacturing

This paper aims at an equation based simulation, CAD modeling and manufacturing of a fractal surface embedded on a musical cymbal. This study is a proof-of-concept of a new method of complex-surface characterization, design and manufacturing using an equation-based approach. A cymbal shape was chosen to carry the fractal profile because generally most musical cymbals have an inherent broken surface pattern that is created to enhance the resulting musical quality. A fractal surface cymbal model was developed; a point cloud representation of the cymbal was generated from Matlab; a surface model was built and processed in image data processing software Imageware; a solid model was completed in CAD software PRO/E; a rapid prototype of the fractal surface cymbal was fabricated; and MasterCam software was used to generate CNC codes and simulate the CNC machining process. The effect of the variation of the parameters of the equation based surface is also shown by varying the topothesy and fractal parameter of the surface.

Design and manufacture of surface textures on gun cartridge cases to trap DNA material

US and Australian work has shown that the effectiveness of extracting deoxyribonucleic acid (DNA) from standard gun cartridges is low and so analysis costs are high ( www.cci.gov/Reference/LpDNACtg_files ). The presence of greater than 1 ng of trapped bio-material would increase the success rates of DNA profiling and facilitate cheaper DNA analysis. The aim of this work is to increase the amount of recoverable DNA from a gun user deposited on fired cartridges, using microtextured surfaces as DNA receptors. Success would increase the probability of identifying perpetrators of gun crime through DNA matching. Various textures have been applied to flat surfaces of cartridge case material and the effects of those surface textures on trapping skin materials have been evaluated. In addition to treated/patterned surfaces, standard emery abrasive paper was adopted as a control medium. From the different surfaces tested, the emery abrasive paper was found to be most effective at trapping skin debris. Rough surfaces with pyramid textures, which are similar to features on emery paper, were subsequently manufactured on cartridge rims by a standard knurling process. Scratch tests were carried out to simulate the process of handling and loading these cartridges during the use of firearms. DNA test results of the knurled cartridges after firing, showed a high success rate of DNA profiling and high matching percentage to the donor's DNA profile.

Local coefficient of friction, sub-surface stresses and temperature distribution during sliding contact

The effects of roughness are important in the design of surface texture to minimise friction and wear. In this paper, we developed a three-dimensional numerical model to study the contact between a rough surface and a rigid plane. Important data induced normal loads distribution, local coefficient of friction, and then the tangential load on each asperity. We can also determine the stress distribution, which depends on the contact pressure, real area of contact and local coefficient of friction. The temperature distribution owing to the heat generation over the real contact areas for sliding problems can be given. This parameter depends on the size of the real contact area, the coefficient of friction, the sliding speed and the thermal material properties.

Geometrical & Interfacial Modulation of a Biomimetic Spinal Implant

The nucleus of a spinal disc is seamlessly connective and protectively supportive of the joint within which it is enveloped. A range of nucleus prosthesis configurations have been proposed and applied with some success. Those that have demonstrated clinical efficacy have approximated physiological form and function using established biomaterials while preserving key anatomical structures. The minimally invasive biostable, biomimetic Columna Disc Device (CDD) partial spinal disc replacement has been developed to clinical trial stage. It mimics the geometry and response of the nucleus that it replaces. While the implant configuration and materials have been set, the geometry and interfacial properties of this prosthesis may be modulated to account for versatility in surgical deployment, implant stiffness, and subsequent long-term tissue remodelling response. FEA models were developed to study effects of implant jacket geometry and surface properties on implant deployment and biomechanics. Studded and dimpled textures provide a method for increasing surface area to diffuse jacket-filler interfacial stress and similar for the implant-tissue junction. Surface texture design elements observed in nature can protect against delamination and interlayer slippage. This is the case with adherent outer layers of human skin. A textured implant design is also proposed to guard against third body wear by housing debris remote of wear sites and by reducing sliding. The periodically varying strain fields provided by the textured jacket may also help mitigate for tears by diverting and arresting micro-fissures. Increasing friction at the implant-tissue interface to the point of tissue-attachment was shown to increase the stiffness of the implant in axial-loading. In contrast, increasing bulk surface area is expected to contribute to a decrease in implant stiffness. This is, however, dependent on the intimacy and properties of interfacing tissues.