Search results
1 – 10 of over 6000Banda Kane, Guillaume Wasselynck, Didier Trichet and Gérard Berthiau
This study aims to introduce a predictive homogenization model incorporating electrical percolation considerations to forecast the electrical characteristics of unidirectional…
Abstract
Purpose
This study aims to introduce a predictive homogenization model incorporating electrical percolation considerations to forecast the electrical characteristics of unidirectional carbon-epoxy laminate composites.
Design/methodology/approach
This study presents a method for calculating the electrical conductivity tensor for various ply arrangement patterns to elucidate phenomena occurring around the interfaces between plies. These interface models are then integrated into a three-dimensional (3D) magneto-thermal model using the finite element method. A comparative study is conducted between different approaches, emphasizing the advantages of the new model through experimental measurements.
Findings
This research facilitates the innovative integration of electrical percolation considerations, resulting in substantial improvement in the prediction of electrical properties of composites. The validity of this improvement is established through comprehensive validation against existing approaches and experimentation.
Research limitations/implications
The study primarily focuses on unidirectional carbon-epoxy laminate composites. Further research is needed to extend the model's applicability to other composite materials and configurations.
Originality/value
The proposed model offers a significant improvement in predicting the electrical properties of composite materials by incorporating electrical percolation considerations at inter-ply interfaces, which have not been addressed in previous studies. This research provides valuable information to improve the accuracy of predictions of the electrical properties of composites and offers a methodology for accounting for these properties in 3D magneto-thermal simulations.
Details
Keywords
Muhammad Ali, Saira Faisal, Shenela Naqvi, Khadija Abdul Wahab, Rida Afreen and Long Lin
The purpose of this study is to investigate the utility of carbon black containing coating formulations that are conventionally used for pigment printing of textiles in…
Abstract
Purpose
The purpose of this study is to investigate the utility of carbon black containing coating formulations that are conventionally used for pigment printing of textiles in fabricating electrically heated fabrics.
Design/methodology/approach
Specifically, electrical and thermal characterisation of the coating system was carried out to establish the feasibility of the system for use in the manufacturing of flexible heating elements on textile substrates. The coating formulations were applied via a simple padding technique followed by stitching the electrodes using a conductive yarn.
Findings
The heating elements of different sizes thus produced showed Ohmic behaviour as a resistor and attained a targeted temperature difference of up to 40°C within the applied voltage range. A prototype heater was also produced, and thermography results showed uniform heating and cooling of the heater that was incorporated into a jacket.
Originality/value
The proposed method is envisaged to be very practical for the realisation of completely textile-based heating elements of different shapes and sizes. Furthermore, the proposed manufacturing method can be used to convert conventional ready-made articles of clothing into heated textiles for various applications.
Details
Keywords
Mun Teng Soo, Kuan Yew Cheon and Ahmad Fauzi Mohd Noor
The purpose of this paper is to report on metal‐oxide‐semiconductor (MOS) capacitor‐based O2 sensors with different catalytic metal electrode (Al or Pd), deposited on both smooth…
Abstract
Purpose
The purpose of this paper is to report on metal‐oxide‐semiconductor (MOS) capacitor‐based O2 sensors with different catalytic metal electrode (Al or Pd), deposited on both smooth and porous surface (pore diameter ranging from 2.76 to 71.6 μm) of ZrO2 thin film.
Design/methodology/approach
The ZrO2 thin film has been prepared by RF sputtering and DC magnetron sputtering process followed by thermal oxidation process, whereas the electrodes were deposited on thin film by thermal evaporation. The sensors are exposed to O2 gas ambient at room temperature and the O2 sensing performance has been examined by surface characterizations and on‐line sensing electrical characterizations.
Findings
MOS capacitor O2 sensor with Pd electrode on porous ZrO2 thin film has the best sensitivity in term of both adsorption and desorption of gas. This sensor is proved to be operated in both capacitor and diode modes.
Originality/value
The paper demonstrates that room temperature MOS‐based O2 sensor operates in capacitor and diode mode conditions with focus on the effect of ZrO2 surface morphology on the sensing properties.
Details
Keywords
M.K. Rendale, S.D. Kulkarni, D.C. Kulkarni and Vijaya Puri
The purpose of this paper is to investigate the effect of Mg2+substitution on the magnetic and electrical properties of Li0.35−x Mg2x Zn0.3 Fe2.35−xO4 thick films synthesized with…
Abstract
Purpose
The purpose of this paper is to investigate the effect of Mg2+substitution on the magnetic and electrical properties of Li0.35−x Mg2x Zn0.3 Fe2.35−xO4 thick films synthesized with polyvinyl alcohol (PVA) matrix.
Design/methodology/approach
The nanoferrites Li0.35−x Mg2x Zn0.3 Fe2.35−xO4 (x=0, 0.07, 0.14, 0.21, 0.28 and 0.35) were synthesized by chemical technique using aqueous solution of PVA (the matrix) and thick films were fabricated by screen printing technique. The DC magnetic hysteresis measurements, AC magnetic susceptibility and DC electrical resistivity were measured as a function of temperature.
Findings
The lattice parameter of thick film Li0.35−x Mg2x Zn0.3 Fe2.35−xO4 (x=0, 0.07, 0.14, 0.21, 0.28 and 0.35) increases with the substitution of Mg2+ions for Li1+and Fe3+. The surface morphology of the thick films showed the grain size increasing with Mg2+substitution till x=0.21 and then decreasing for the higher concentrations of magnesium. The magnetic moment nB (μB) computed from the Ms obtained by extrapolation of the magnetization curve showed a gradual decrease with the composition till x=0.21, beyond which a sudden decrease was observed. The resistivity of the films at room temperature had variation with composition x, similar to that of magnetic moment. The activation energies ΔEF and ΔEP were found to vary with composition x of the ferrite system.
Originality/value
The paper reports, for the first time, the magnetic and electrical properties of fritless Li0.35−xMg2xZn0.3Fe2.35−xO4 thick films using PVA polymer matrix. Up to x=0.21 (Mg2+), grain size increases and Curie temperature decreases beyond which reverse effect takes place.
Details
Keywords
The once highly publicised Porcelain Enamelled Steel (PES) substrates seem to have disappeared from the public gaze, or have they? They certainly have not. If anything, they have…
Abstract
The once highly publicised Porcelain Enamelled Steel (PES) substrates seem to have disappeared from the public gaze, or have they? They certainly have not. If anything, they have consolidated their place in electronics applications and are growing in use at a remarkable pace in particular applications supplied by the major USA source, namely Ferro‐ECA.
Thejas Ramakrishnaiah, Prasanna Gunderi Dhananjaya, Chaturmukha Vakwadi Sainagesh, Sathish Reddy, Swaroop Kumaraswamy and Naveen Chikkahanumajja Surendranatha
This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of…
Abstract
Purpose
This paper aims to study the various developments taking place in the field of gas sensors made from polyaniline (PANI) nanocomposites, which leads to the development of high-performance electrical and gas sensing materials operating at room temperature.
Design/methodology/approach
PANI/ferrite nanocomposites exhibit good electrical properties with lower dielectric losses. There are numerous reports on PANI and ferrite nanomaterial-based gas sensors which have good sensing response, feasible to operate at room temperature, requires less power and cost-effective.
Findings
This paper provides an overview of electrical and gas sensing properties of PANI/ferrite nanocomposites having improved selectivity, long-term stability and other sensing performance of sensors at room temperature.
Originality/value
The main purpose of this review paper is to focus on PANI/ferrite nanocomposite-based gas sensors operating at room temperature.
Details
Keywords
Wearable electronics is an emerging technology predicted to become a 50B$ industry by 2018. Components and circuits will be highly integrated into clothing and other apparel. One…
Abstract
Purpose
Wearable electronics is an emerging technology predicted to become a 50B$ industry by 2018. Components and circuits will be highly integrated into clothing and other apparel. One crucial factor is the need for highly robust, flexible printed circuit tracks with sufficiently high electrical conductivity. The fact that metal-based tracks tend to suffer from fatigue failure has driven the development of alternative materials. The paper aims to discuss these issues.
Design/methodology/approach
Alternative materials are organic conductors and carbon nanotubes. The latter has a great flexibility and intrinsic strength. While nanotubes can be solubilised and printed using ink-jet techniques, this usually requires polymer additives. The paper has therefore sought to develop a novel solvent-free dry-ink.
Findings
The paper has found that it is possible to directly transfer from a nanotube growth substrate, via a hard print stamp head, onto a flexible rubber substrate and that one loading of the stamp can give many individual prints before exhaustion: the dry-ink stamp face effectively de-layers by a set amount each time a print is made. Many consecutive, highly consistent and uniform prints can be made using this approach. When printed onto natural rubber, the printed tracks are very robust and can be stretched to 100 per cent strain without permanent damage. The electrical conductivity can be improved by a simple alcohol treatment to consolidate the fibers and by iodine doping reaching 38 S · cm−1.
Originality/value
The findings offer an economical way to print highly robust electrically conductive tracks of carbon nanotubes directly onto flexible substrates.
Details
Keywords
Novel nanomaterials and nano-devices require further functional aspects that can be designed and supported using new nanomanipulation techniques allowing specific functions at the…
Abstract
Purpose
Novel nanomaterials and nano-devices require further functional aspects that can be designed and supported using new nanomanipulation techniques allowing specific functions at the design phase. The nano-manipulator becomes a key instrument for technology bridging sub-nano to mesoscale. The integration of various operations in nano-devices requires sub-nanometer precision and highly stable manipulator. This paper aims to review various design concepts of recent nanomanipulators, their motion characteristics, basic functions, imagine and automation with control techniques for the sake of establishing new design features based on recent requirements.
Design/methodology/approach
The paper reviews various existing nanomanipulators, their motion characteristics, basic functions, imagine and automation with control techniques. This will support precision machine design methodology and robotics principles.
Findings
The availability of a nano-precision instrument with integrated functions has proved to be extremely helpful in addressing various fundamental problems in science and engineering such as exploring, understanding, modeling and testing nano-machining process; exact construction of nano-structure arrays; and inspection of devices with complex features.
Originality/value
New functional specifications have emerged from this review to support the design and make of new advanced nanomanipulators with more features availability to support manipulation within the same reference datum needed for research and education.
Details
Keywords
Prithivi Rajan V. and Punitha A.
This paper aims to design a radio frequency micro-electro-mechanical system (RF MEMS)-based phase shifter using chamfered coplanar waveguide (CPW) transmission line (t-line) with…
Abstract
Purpose
This paper aims to design a radio frequency micro-electro-mechanical system (RF MEMS)-based phase shifter using chamfered coplanar waveguide (CPW) transmission line (t-line) with open-circuit interdigital metal–air–metal (ID MAM) capacitors.
Design/methodology/approach
The proposed phase shifter achieves maximum differential phase shift with low loss at Ku band. The phase shifter is built with one switchable fixed-fixed beam (MEMS switch) on chamfered CPW t-line in series with two planar open-circuit ID MAM capacitors. An equivalent circuit model for the proposed phase shifter is derived, and its parameters are extracted using an electromagnetic (EM) solver.
Findings
The MEMS switch is actuated using an electrostatic method with the calculated residual stress of 44.26 MPa. The fabricated phase shifter exhibits low insertion loss, close to 0.14 dB at 17 GHz, with the maximum phase shift of 15.06°. The return loss is greater than 23 dB between 12 and 18 GHz.
Originality/value
This phase shifter presents a promising solution for low loss applications in the Ku band with a maximum phase shift. As the maximum phase shift of 15.06° is achieved for a unit cell with low insertion loss, the phase shifter is found to be feasible for modern electronically tunable phased arrays used for satellite communication and radar systems.
Details
Keywords
Abstract
Details