Search results
1 – 10 of 74
This paper aims to provide an overview of the strategies and techniques being used and developed for the fabrication of nanoscale devices.
Abstract
Purpose
This paper aims to provide an overview of the strategies and techniques being used and developed for the fabrication of nanoscale devices.
Design/methodology/approach
This paper discusses various nanofabrication technologies and strategies and highlights their merits and limitations. It concludes with a consideration of longer‐term possibilities.
Findings
It is shown that top‐down nanofabrication frequently uses lithographic and other techniques derived from the microtechnology industry but recent research appears to have identified a limit to its capabilities. Bottom‐up nanofabrication is less well‐developed but techniques such as molecular mechanosynthesis may offer unique capabilities in the longer‐term.
Originality/value
The paper provides a timely review of the rapidly developing field of nanofabrication technology.
Details
Keywords
Abstract
Details
Keywords
Job Maveke Wambua, Fredrick Madaraka Mwema, Stephen Akinlabi, Martin Birkett, Ben Xu, Wai Lok Woo, Mike Taverne, Ying-Lung Daniel Ho and Esther Akinlabi
The purpose of this paper is to present an optimisation of four-point star-shaped structures produced through additive manufacturing (AM) polylactic acid (PLA). The study also…
Abstract
Purpose
The purpose of this paper is to present an optimisation of four-point star-shaped structures produced through additive manufacturing (AM) polylactic acid (PLA). The study also aims to investigate the compression failure mechanism of the structure.
Design/methodology/approach
A Taguchi L9 orthogonal array design of the experiment is adopted in which the input parameters are resolution (0.06, 0.15 and 0.30 mm), print speed (60, 70 and 80 mm/s) and bed temperature (55°C, 60°C, 65°C). The response parameters considered were printing time, material usage, compression yield strength, compression modulus and dimensional stability. Empirical observations during compression tests were used to evaluate the load–response mechanism of the structures.
Findings
The printing resolution is the most significant input parameter. Material length is not influenced by the printing speed and bed temperature. The compression stress–strain curve exhibits elastic, plateau and densification regions. All the samples exhibit negative Poisson’s ratio values within the elastic and plateau regions. At the beginning of densification, the Poisson’s ratios change to positive values. The metamaterial printed at a resolution of 0.3 mm, 80 mm/s and 60°C exhibits the best mechanical properties (yield strength and modulus of 2.02 and 58.87 MPa, respectively). The failure of the structure occurs through bending and torsion of the unit cells.
Practical implications
The optimisation study is significant for decision-making during the 3D printing and the empirical failure model shall complement the existing techniques for the mechanical analysis of the metamaterials.
Originality/value
To the best of the authors’ knowledge, for the first time, a new empirical model, based on the uniaxial load response and “static truss concept”, for failure mechanisms of the unit cell is presented.
Details
Keywords
Gianluca Ruffato and Filippo Romanato
– The purpose of this paper is to simulate and analyze the excitation and propagation of surface plasmon polaritons (SPPs) on sinusoidal metallic gratings in conical mounting.
Abstract
Purpose
The purpose of this paper is to simulate and analyze the excitation and propagation of surface plasmon polaritons (SPPs) on sinusoidal metallic gratings in conical mounting.
Design/methodology/approach
Chandezon's method has been implemented in MATLAB environment in order to compute the optical response of metallic gratings illuminated under azimuthal rotation. The code allows describing the full optical features both in far- and near-field terms, and the performed analyses highlight the fundamental role of incident polarization on SPP excitation in the conical configuration.
Findings
Results of far-field polarization conversion and plasmonic near-field computation clearly show that azimuthally rotated metallic gratings can support propagating surface plasmon with generic polarization.
Originality/value
The recent papers experimentally demonstrated the benefits in sensitivity and the polarization phenomenology that are originated by an azimuthal rotation of the grating. In this work, numerical simulations confirm these experimental results and complete the analysis with a study of the excited SPP near-field on the metal surface.
Details
Keywords
Sule Ugur, Merih Sarıışık, Gizem Türkoğlu, Gökhan Erkan and Emre Erden
The purpose of this paper is to create a textile material which shows antibacterial activity with resistance to environmental conditions by using volatile active agent inclusion…
Abstract
Purpose
The purpose of this paper is to create a textile material which shows antibacterial activity with resistance to environmental conditions by using volatile active agent inclusion complex and self-assembly method.
Design/methodology/approach
An inclusion complex of carvacrol and β-CD is generated by kneading method and deposited on the cotton fabrics by using a nanofabrication method named as layer-by-layer (LbL) deposition method. Three different concentration of CD and CD:Car aqueous solutions were deposited on cotton fabrics. Attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR), scanning electron microscopy (SEM), antimicrobial efficacy test of fabrics against washing and some physical tests (water vapor permeability, air permeability) were performed on the fabrics before and after the treatment with CD to evaluate the effect of the LbL process on cotton fabric properties.
Findings
The results showed that the coated fabrics with CD/CD:Car multilayer films enhanced the antimicrobial efficacy of cotton fabrics against to Klebsiella pneumonia and Staphylococus aureus bacteria. Air and water vapor permeability properties of the cotton fabric effected after the LbL deposition process sure enough. With SEM and FTIR-ATR analysis the CD:Car complex presence were verified. The durability of antibacterial properties were analyzed after one and ten washing (40°C and 30 min) cycles.
Originality/value
This work provides a novel and simple method for CD and inclusion complex of carvacrol film deposition by self-assembly method on cotton fabrics and their application onto cotton fabrics to gain antibacterial property.
Details
Keywords
Osvaldo J. Arenas, Emilie Leynia de la Jarrige and François Boone
The purpose of this paper is to share valuable information about low‐cost microwave circuit research with academic and industrial communities that work, or want to work, in this…
Abstract
Purpose
The purpose of this paper is to share valuable information about low‐cost microwave circuit research with academic and industrial communities that work, or want to work, in this field.
Design/methodology/approach
Screen‐printing technology has been chosen as the fabrication method because of simplicity and low costs. Different materials and printing parameters were tested in four generations of microstrip lines. After obtaining a satisfactory fabrication method, passive microwave components were printed, assembled, characterized and modeled.
Findings
Results demonstrated that the proposed low‐cost method allows fabricating low loss microstrip lines (15.63×10−3 dB/mm at 10 GHz), filters, inductors, and capacitors that work well up to 12 GHz.
Research limitations/implications
Model accuracy of inductors and capacitors can be improved. The use of more precise calibration and de‐embedding techniques is necessary. More components can be fabricated and modeled to increase the flexibility and applicability of the proposed fabrication method.
Practical implications
The presented information can help limited budget companies and small educational institutions in electronics to fabricate microwave circuits at low costs. This is an excellent approach for students who want to learn how to make microwave frequency measurements and circuits without the need of expensive fabrication equipment and clean rooms.
Originality/value
The step‐by‐step fabrication method described in this paper allows fabricating different microwave components at low costs. The presentation of electrical models for each component completes the design‐fabrication cycle. As this information is gathered in a single source, it makes easier the incursion of new actors in the microwave field.
Details