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Article
Publication date: 7 March 2016

Haibao Lu, Yongtao Yao, Jinying  Yin and Long Lin

This paper aims to study the synergistic effect of self-assembled carboxylic acid-functionalised carbon nanotube (CNT) and nafion/silica nanofibre nanopaper on the…

Abstract

Purpose

This paper aims to study the synergistic effect of self-assembled carboxylic acid-functionalised carbon nanotube (CNT) and nafion/silica nanofibre nanopaper on the electro-activated shape memory effect (SME) and shape recovery behaviour of shape memory polymer (SMP) nanocomposite.

Design/methodology/approach

Carboxylic acid-functionalised CNT and nafion/silica nanofibre are first self-assembled onto carbon fibre by means of deposition and electrospinning approaches, respectively, to form functionally graded nanopaper. The combination of carbon fibre and CNT is introduced to enable the actuation of the SME in SMP by means of Joule heating at a low electric voltage of 3.0-5.0 V.

Findings

Nafion/silica nanofibre is used to improve the shape recovery behaviour and performance of the SMP for enhanced heat transfer and electrical actuation effectiveness. Low electrical voltage actuation and high electrical actuation effectiveness of 32.5 per cent in SMP has been achieved.

Research limitations/implications

A simple way for fabricating electro-activated SMP nanocomposites has been developed by using functionally graded CNT and nafion/silica nanofibre nanopaper.

Originality/value

The outcome of this study will help to fabricate the SMP composite with high electrical actuation effectiveness under low electrical voltage actuation.

Details

Pigment & Resin Technology, vol. 45 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 16 July 2019

Mariusz Żokowski, Krzysztof Falkowski, Paulina Kurnyta-Mazurek and Maciej Henzel

The paper presents the results of work on control systems of bearingless electric motors. Authors proposed the applications of bearingless electric machines for aircraft…

Abstract

Purpose

The paper presents the results of work on control systems of bearingless electric motors. Authors proposed the applications of bearingless electric machines for aircraft actuation system. Suggested solution characterizes novel concept of on-board equipment design such as More Electric Aircraft. Magnetic suspension technology allows elimination of friction force and the negative performance features of classic bearing system. However, to achieve all these purposes appropriately, dedicated control system must be also applied.

Design/methodology/approach

The development of a control system of bearingless electric machine is presented in detail. Mathematical model and construction of induction bearingless motor are widely discussed. Then, proportional–integral-derivative controller algorithm designing for BEM control system was presented using the well pole placement method. Simulation model of BEM control system with use of Matlab-Simulink software was shown. Finally, experimental studies on laboratory stand were introduced. The paper presents design methodology of conventional and advanced control system of bearingless motor.

Findings

The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap.

Practical implications

The presented concept of the bearingless electric machines could be applied in the on-board actuation system. During research, full control system of bearingless electric motor was designed and tested. This system consisted of two subsystems. The first responded for rotary speed stabilization and second one was designed for position control of the rotor in the air gap.

Originality/value

The idea of active magnetic suspension system will be implemented for aviation on technology readiness level V. The paper presents unique laboratory stand with bearingless electric motor and experimental studies. The stable time responses of designed control system were presented and discussed. In addition, preliminary considerations of advanced control system with robust controller were introduced as well.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 1
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 15 March 2019

Guangkai Sun, Yang Hu, Mingli Dong, Yanlin He, Mingxin Yu and Lianqing Zhu

Soft robotics is a burgeoning field owing to its high adaptability and safety in human–machine interaction and unstructured environments. However, the feedback control of…

Abstract

Purpose

Soft robotics is a burgeoning field owing to its high adaptability and safety in human–machine interaction and unstructured environments. However, the feedback control of soft actuators with flexible sensors is still a challenge.

Design/methodology/approach

To address this issue, this study proposes an optical fibre-based sensing membrane for the posture measurement of soft pneumatic bending actuators. The major contribution is the development of a flexible sensing membrane with a high sensitivity and repeatability for the feedback control of soft actuators. The characteristics of sensing membrane were analysed. The relationship between wavelength shift and bending curvature was derived. The curvatures of soft actuator were measured at four bending status, and the postures were reconstructed.

Findings

The results indicate that the measurement error is less than 2.1% of the actual bending curvature. The sensitivity is up to 212.8 pm/m−1, and the signal fluctuation in repeated measurements is negligible. This approach has broad application prospects in soft robotics, because it makes the optical fibre achieve more strength and compatible with soft actuators, thus improving the sensing accuracy, sensitivity and reliability of fibre sensors.

Originality/value

Different from previous approaches, an optical fibre with FBGs is embedded into a multilayered polyimide film to form a flexible sensing membrane, and the membrane is embedded into a soft pneumatic bending actuator as the smart strain limited layer which is able to measure the posture in real time. This approach makes the optical fibre stronger and compatible with the soft pneumatic bending actuator, and the sensing accuracy, sensitivity and reliability are improved. The proposed sensing configuration is effective for the feedback control of the soft pneumatic bending actuators.

Details

Industrial Robot: the international journal of robotics research and application, vol. 46 no. 1
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 October 1997

P.G. Frankling

High speed cartoning offers a convenient way to pack a wide range of products. Sift‐proof sealing is a technique which can provide major savings in energy and raw…

Abstract

High speed cartoning offers a convenient way to pack a wide range of products. Sift‐proof sealing is a technique which can provide major savings in energy and raw materials, thus reducing both cost and demands on resources. PVA has been the traditional adhesive used, but hot‐melt adhesives have a number of advantages, not least of which is speed. This is becoming increasingly important as packers demand greater production speeds and so hot‐melt adhesives are gradually supplanting PVA. Both elements of the process, adhesive and application equipment, will have to be skilfully engineered in order to cope with the added stresses placed on them by these high speeds. An exciting new development of the sift‐proof technique has recently been unveiled, whereby a treated paper membrane is bonded to the inside of the carton at each end. Not only does this provide a means of applying a complete “circuit” of hot melt to give a totally air‐tight pack but its barrier properties allow the carton to be used for perishable products. Further developments of the sift‐proof technique in the future can be expected.

Details

Pigment & Resin Technology, vol. 26 no. 5
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 January 2014

Haibao Lu, Yongtao Yao and Long Lin

This article aims to present a systematic and up-to-date account of carbon-based reinforcements, including carbon nanotube (CNT), carbon nanofibre (CNF), carbon black…

Abstract

Purpose

This article aims to present a systematic and up-to-date account of carbon-based reinforcements, including carbon nanotube (CNT), carbon nanofibre (CNF), carbon black (CB), carbon fibre (CF) and grapheme, in shape-memory polymer (SMP) for electrical actuation.

Design/methodology/approach

Studies exploring carbon-based reinforcement in SMP composites for electrically conductive performance and Joule heating triggered shape recovery have been included, especially for the principle design, characterisation and shape recovery behaviour, making the article a comprehensive account of the systemic progress in SMP composite incorporating conductive carbon reinforcement.

Findings

SMPs are fascinating materials and have attracted great academic and industrial attention owing to their significant macroscopic shape deformation in the presence of an appropriate stimulus. The working mechanisms, the physico requirements and the theoretical origins of the different types of carbon-based reinforcement SMP composites have been discussed. Current research and development on the fabrication strategies of carbon-based reinforcement SMP composites have been summarised.

Research limitations/implications

A systematic review is to evaluate carbon-based reinforcements in SMPs for electrical actuation and discuss recent developments and future applications.

Practical implications

Carbon-based reinforcements in SMPs can be used as smart deployable space structure in the broad field of aerospace technologies.

Originality/value

To reveal the research and development of utilising CNT, CNF, CB, CF and grapheme to achieve shape recovery of SMP composites through electrically resistive heating, which will significantly benefit the research and development of smart materials and systems.

Details

Pigment & Resin Technology, vol. 43 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 5 May 2015

Haibao Lu, Yongtao Yao, Shipeng Zhu, Yunhua Yang and Long Lin

The purpose of this paper is a study aimed at overcoming the interface issue between nanopaper and polymer matrix in shape-memory polymer (SMP) composite laminates caused…

Abstract

Purpose

The purpose of this paper is a study aimed at overcoming the interface issue between nanopaper and polymer matrix in shape-memory polymer (SMP) composite laminates caused by their large dissimilarity in electrical/thermal conductive properties. The study attempted to develop an effective approach to fabricate free-standing carbon nanofibre (CNF) assembly in octagon shape formation. The structure design and thermal conductive performance of the resulting octagon-shaped CNF assembly were optimised and simulated.

Design/methodology/approach

The CNF nanopaper was prepared based on a filtration method. The SMP nanocomposites were fabricated by incorporating these CNF assemblies with epoxy-based SMP resin by a resin-transfer modelling technique. Thermal conductivity of the octagon-shaped CNF assembly was simulated using the ANSYS FLUENT software for structure design and optimisation. The effect of the octagon-shaped CNF on the thermomechanical properties and thermally responsive shape-memory effect of the resulting SMP nanocomposites were characterised and interpreted.

Findings

The CNF template incorporated with SMP to achieve Joule heating triggered shape recovery at a low electric voltage of 3-10 V, due to which the electrical resistivity of SMP nanocomposites was significantly improved and lowered to 0.20 O·cm by the CNF template. It was found that the octagon CNF template with 2 mm width of skeleton presented a highest thermally conductive performance to transfer resistive heat to the SMP matrix.

Research limitations/implications

A simple way for fabricating electro-activated SMP nanocomposites has been developed by using an octagon CNF template. Low electrical voltage actuation in SMP has been achieved.

Originality/value

The fabricated CNF template, the structure design and analysis of dynamic thermomechanical properties of SMP are novel.

Details

Pigment & Resin Technology, vol. 44 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 16 November 2010

Siddiq M. Qidwai and V.G. DeGiorgi

The paper aims to highlight the computational implementation of a nonlinear piezoelectric constitutive model and its application in determining the impact of misalignment…

Abstract

Purpose

The paper aims to highlight the computational implementation of a nonlinear piezoelectric constitutive model and its application in determining the impact of misalignment between initial poling direction and applied electrical field, and mechanical boundary conditions on actuator performance.

Design/methodology/approach

The numerical analysis is based on an existing three‐dimensional model, where the original rate‐independent evolution equations are replaced by their rate‐dependent counterparts to facilitate implementation, which is performed in a partial differential equation solver. The execution of the model is verified through several benchmark constitutive responses.

Findings

The analysis shows that small angles of poling and loading axes misalignment such as may occur in fabrication (less than 5) have minor impact on piezoelectric performance regardless of the type of imposed mechanical boundary conditions. On the other hand, larger angles of misalignment can have a significant impact, the feasibility of which in actuator design remains to be seen. Furthermore, it is shown that the linear response range of these actuators can be expanded by increased levels of mechanical constraint at the cost of maximum actuation stroke regardless of the degree of misalignment.

Originality/value

The misalignment, which occurs accidentally, but can also be introduced purposefully during the fabrication process when poled material is cut into specimen form, may exhibit desirable performance features for actuator design when combined with appropriate mechanical constraints.

Details

Engineering Computations, vol. 27 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

Content available
Article
Publication date: 1 February 2005

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 77 no. 1
Type: Research Article
ISSN: 0002-2667

Keywords

Content available
Article
Publication date: 1 June 2001

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 73 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 2 January 2018

Reza Hadjiaghaie Vafaie

The on-chip high-throughput mixing process is one of the main challenges in the preparation process in clinical diagnostics. Because of high laminar flow in micro-channel…

Abstract

Purpose

The on-chip high-throughput mixing process is one of the main challenges in the preparation process in clinical diagnostics. Because of high laminar flow in micro-channel, the fluid should be disturbed by external force. This paper aims to study pulsed AC electrothermal flow and the multiphysic interaction between the fluid behavior, external electric field, temperature field and convection-diffusion field to generate perturbation effect inside the channel.

Design/methodology/approach

A set of numerical simulations were carried out by multiphysic interactions between the fluid behavior, external electric field, temperature field and convection-diffusion field to generate the pulsed AC electrothermal flow inside the channel. Behavior of electrode–electrolyte system is discussed using the electrical lumped circuit model.

Findings

Highly efficient temperature gradients are generated by applying pulsed electric potential over the electrodes; as a result, efficient secondary flows form inside the channel. The proposed method increases the interfacial contact area between the fluids and enhances the molecular diffusion transport phenomena. Maximum temperature rise of 4.1 K is observed in the gap between the electrodes for 0.08 S/m fluid medium, where the electric field is much stronger than elsewhere. Velocity field and concentration analysis reveal high performance perturbation effects for the mixing process. The periodic stretching and folding effects increase the interfacial contact area between the fluids by using pulsed AC electrothermal flow. Based on the results, 83 per cent mixing efficiency is achieved for 0.08 S/m fluid medium with a microchannel length of 400 µm. Both the mixing efficiency and generated temperature rise increase by increasing the fluid ionic strength.

Originality/value

The ability to generate low temperature rise is very important for AC electrothermally driven fluidic chips such as immunoassay chips. In the present research, a novel actuation mechanism has been proposed to generate AC electrothermal manipulation mechanism and enhance the mixing efficiency by using pulsed AC electrothermal flow.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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