Search results
1 – 10 of 55Kai Zhuang, Jieru Xiao and Xiaolong Yang
The purpose of this paper is to show that the droplet impact phenomenon is important for the advancement of industrial technologies in many fields such as spray cooling and ink…
Abstract
Purpose
The purpose of this paper is to show that the droplet impact phenomenon is important for the advancement of industrial technologies in many fields such as spray cooling and ink jet printing. Droplet bouncing on the nonwetting surfaces is a special phenomenon in the impact process which has attracted lots of attention.
Design/methodology/approach
In this work, the authors fabricated two kinds of representative nonwetting surfaces including superhydrophobic surfaces (SHS) and a slippery liquid-infused porous surface (SLIPS) with advanced UV laser processing.
Findings
The droplet bouncing behavior on the two kinds of nonwetting surfaces were compared in the experiments. The results indicate that the increasing Weber number enlarges the maximum droplet spreading diameter and raises the droplet bounce height but has no effect on contact time.
Originality/value
In addition, the authors find that the topological SHS and SLIPS with the laser-processed microwedge groove array produce asymmetric droplet bouncing with opposite offset direction. Microdroplets can be continuously transported without any additional driving force on such a topological SLIPS. The promising method for manipulating droplets has potential applications for the droplet-based microfluidic platforms.
Details
Keywords
A. Syafiq, A.K. Pandey, Vengadaesvaran Balakrishnan and Nasrudin Abd Rahim
The paper aims to investigate the effect of Degussa P-25 Titanium Dioxide (TiO2) nanoparticles on hydrophobicity and self-cleaning ability as a single organic coating on glass…
Abstract
Purpose
The paper aims to investigate the effect of Degussa P-25 Titanium Dioxide (TiO2) nanoparticles on hydrophobicity and self-cleaning ability as a single organic coating on glass substrate.
Design/methodology/approach
Two methods have been used to enhance the hydrophobicity on glass substrates, namely, surface modification by using low surface energy isooctyltrimethoxysilane (ITMS) solution and construction of rough surface morphology using Degussa P-25 TiO2 nanoparticles with simple bottom-up approach. The prepared sol was applied onto glass substrate using dip-coating technique and stoved in the vacuum furnace 350°C.
Findings
The ITMS coating with nano TiO2 pigment has modified the glass substrate surface by achieving the water contact angle as high as 169° ± 2° and low sliding angle of 0° with simple and low-cost operation. The solid and air phase interface has created excellent anti-dirt and self-cleaning properties against dilute ketchup solution, mud and silicon powder.
Research limitations/implications
Findings will be useful in the development of self-cleaning and anti-dirt coating for photovoltaic panels.
Practical implications
Sol method provides the suitable medium for the combination of organic–inorganic network to achieve high superhydrophobicity and optimum self-cleaning ability.
Originality/value
Application of blended organic–inorganic sol as self-cleaning and anti-dirt coating film.
Details
Keywords
The purpose of this paper is to describe recent research involving the application of biomimetic design concepts to nanosensor developments.
Abstract
Purpose
The purpose of this paper is to describe recent research involving the application of biomimetic design concepts to nanosensor developments.
Design/methodology/approach
Following a short introduction to nanobiomimetic concepts, this paper discusses a range of recent nanosensor developments whose designs mimic or use naturally‐occurring nanostructures or nanomaterials.
Findings
This shows that biomimetic design concepts are being applied to a range of nanosensors which have been shown to respond to a range of physical and chemical variables, often with very high sensitivities. Potential applications include homeland security and military uses, healthcare and robotics.
Originality/value
This paper provides details of recent nanobiomimetic sensor research which has potential in a range of critical applications.
Details
Keywords
Jai Manik, Amaresh Dalal and Ganesh Natarajan
The purpose of this paper is to numerically investigate the effect of various parameters such as density ratio, surface wettabilities and Weber number on the droplet dripping and…
Abstract
Purpose
The purpose of this paper is to numerically investigate the effect of various parameters such as density ratio, surface wettabilities and Weber number on the droplet dripping and detachment process.
Design/methodology/approach
By using algebraic volume of fluid method, the governing equations are solved using a collocated finite volume approach in two-dimensions.
Findings
The results indicate that, for small densities of droplet, it adheres to the surface except when the surface is hydrophobic, while an increase in Weber number or presence of an additional droplet in the vicinity led to detachment.
Originality/value
The paper explores various characteristics of a droplet when two competing forces, namely, gravity and surface tension, act simultaneously. The detachment is observed for a given initial droplet size, as it becomes denser in an uniform gravitational field. The effect of droplet affinity for two droplets is also presented using the simulations.
Details
Keywords
Yan Chen, Wenzhuo Chen, Bo Li, Gang Zhang and Weiming Zhang
The purposes of this paper are to review the progress of and conclude the trend for paint thickness simulation for painting robot trajectory planning.
Abstract
Purpose
The purposes of this paper are to review the progress of and conclude the trend for paint thickness simulation for painting robot trajectory planning.
Design/methodology/approach
This paper compares the explicit function-based method and computational fluid dynamics (CFD)-based method used for paint thickness simulation. Previous research is considered, and conclusions with the outlook are drawn.
Findings
The CFD-based paint deposition simulation is the trend for paint thickness simulation for painting robot trajectory planning. However, the calculation of paint thickness resulting from dynamically painting complex surface remains to be researched, which needs to build an appropriate CFD model, study approaches to dynamic painting simulation and investigate the simulation with continuously changing painting parameters.
Originality/value
This paper illustrates that the CFD-based method is the trend for the paint thickness simulation for painting robot trajectory planning. Current studies have been analyzed, and techniques of CFD modeling have also been summarized, which is vital for future study.
Details
Keywords
Yanlin Ren, Zhaomiao Liu, Yan Pang, Xiang Wang and Shanshan Gao
This paper aims to investigate the influence of droplet infiltration and sliding on the deposition size and make a uniform deposition by controlling the interaction between…
Abstract
Purpose
This paper aims to investigate the influence of droplet infiltration and sliding on the deposition size and make a uniform deposition by controlling the interaction between droplets, using the three-dimensional lattice Boltzmann method (LBM) based on the actual working condition.
Design/methodology/approach
D3Q19 Shan-Chen LB approach is developed and optimized based on the metal droplet deposition. The Carnahan-Starling equation of state and transition layers are introduced to maintain the greater stability and low pseudo velocities. In addition, an additional collision term is adopted to implement immersed moving boundary scheme to deal with no-slip boundaries on the front of the phase change.
Findings
The numerical results show that the new¬ incoming droplet wet and slide off the solidified surface and the rejection between droplets are the reasons for the deviation of the actual deposition length. The total length of the longitudinal section negatively correlates with the deposition distance. To improve the dimensional accuracy, the deposition distance and repulsion rate need to be guaranteed. The optimal deposition distance is found to have a negative linear correlation with wettability.
Originality/value
The numerical model developed in this paper will help predict the continuous metal droplet deposition and provide guidance for the selection of deposition distance.
Details
Keywords
Yang Guo, Huseini S. Patanwala, Brice Bognet and Anson W.K. Ma
This paper aims to summarize the latest developments both in terms of theoretical understanding and experimental techniques related to inkjet fluids. The purpose is to provide…
Abstract
Purpose
This paper aims to summarize the latest developments both in terms of theoretical understanding and experimental techniques related to inkjet fluids. The purpose is to provide practitioners a self-contained review of how the performance of inkjet and inkjet-based three-dimensional (3D) printing is fundamentally influenced by the properties of inkjet fluids.
Design/methodology/approach
This paper is written for practitioners who may not be familiar with the underlying physics of inkjet printing. The paper thus begins with a brief review of basic concepts in inkjet fluid characterization and the relevant dimensionless groups. Then, how drop impact and contact angle affect the footprint and resolution of inkjet printing is reviewed, especially onto powder and fabrics that are relevant to 3D printing and flexible electronics applications. A future outlook is given at the end of this review paper.
Findings
The jettability of Newtonian fluids is well-studied and has been generalized using a dimensionless Ohnesorge number. However, the inclusion of various functional materials may modify the ink fluid properties, leading to non-Newtonian behavior, such as shear thinning and elasticity. This paper discusses the current understanding of common inkjet fluids, such as particle suspensions, shear-thinning fluids and viscoelastic fluids.
Originality/value
A number of excellent review papers on the applications of inkjet and inkjet-based 3D printing already exist. This paper focuses on highlighting the current scientific understanding and possible future directions.
Details
Keywords
Gerard Cummins and Marc P.Y. Desmulliez
The purpose of this paper is to present an exhaustive review of research studies and activities in the inkjet printing of conductive materials.
Abstract
Purpose
The purpose of this paper is to present an exhaustive review of research studies and activities in the inkjet printing of conductive materials.
Design/methodology/approach
This paper gives a detailed literature survey of research carried out in inkjet printing of conductive materials.
Findings
This article explains the inkjet printing process and the various types of conductive inks. It then examines the various factors that affect the quality of inkjet printed interconnects such as printing parameters, materials and substrate treatments. Methods of characterising both the inkjet printing process and the electrical properties of printed conductive materials are also presented. Finally relevant applications of this technology are described.
Originality/value
Inkjet printing is currently one of the cheapest direct write techniques for manufacturing. The use of this technique in electronic manufacturing, where interconnects and other conductive features are required is an area of increasing relevance to the fields of electronics manufacturing, packaging and assembly. This review paper would therefore be of great value and interest to this community.
Details
Keywords
The popularity of television shows such as CSI:(insert appropriate city here) makes everyone think they are somehow a forensic expert. The portrayal of this kind of subject on…
Abstract
The popularity of television shows such as CSI:(insert appropriate city here) makes everyone think they are somehow a forensic expert. The portrayal of this kind of subject on radio is of course much more complicated as each observer has an image in their own head rather than in front of their eyes. This chapter seeks to inform The Archers listeners and other interested parties about the Blossom Hill Cottage crime scene examination — what they might expect to have seen from an evidential perspective and how the findings may inform the court as to what really occurred that fateful night. The chapter presents general information about different blood patterns that may be observed at crime scenes such as this and others, what they may (or may not) mean and a discussion about the strengths and limitations of this kind of scientific examination and interpretation. Whilst this can clearly be a serious subject, the intention is to inform and (probably) bust some televisual myths with a light-hearted edge from an Archers fan and fellow Tweetalonger, additionally considering online speculation about other potential evidence.
Details