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Article
Publication date: 13 May 2024

Fay Rhianna Claybrook, Darren John Southee and Mazher Mohammed

Cushioning is a useful material property applicable for a range of applications from medical devices to personal protective equipment. The current ability to apply cushioning in a…

Abstract

Purpose

Cushioning is a useful material property applicable for a range of applications from medical devices to personal protective equipment. The current ability to apply cushioning in a product context is limited by the appropriateness of available materials, with polyurethane foams being the current gold standard material. The purpose of this study is to investigate additively manufactured flexible printing of scaffold structures as an alternative.

Design/methodology/approach

In this study, this study investigates triply periodic minimal surface (TPMS) structures, including Gyroid, Diamond and Schwarz P formed in thermoplastic polyurethane (TPU), as a possible alternative. Each TPMS structure was fabricated using material extrusion additive manufacturing and evaluated to ASTM mechanical testing standard for polymers. This study focuses attention to TPMS structures fabricated for a fixed unit cell size of 10 mm and examine the compressive properties for changes in the scaffold porosity for samples fabricated in TPU with a shore hardness of 63A and 90A.

Findings

It was discovered that for increased porosity there was a measured reduction in the load required to deform the scaffold. Additionally, a complex relationship between the shore hardness and the stiffness of a structure. It was highlighted that through the adjustment of porosity, the compressive strength required to deform the scaffolds to a point of densification could be controlled and predicted with high repeatability.

Originality/value

The results indicate the ability to tailor the scaffold design parameters using both 63A and 90A TPU material, to mimic the loading properties of common polyurethane foams. The use of these structures indicates a next generation of tailored cushioning using additive manufacturing techniques by tailoring both geometry and porosity to loading and compressive strengths.

Details

Rapid Prototyping Journal, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 22 August 2008

R.J.H. Young, P.S.A. Evans, G.I. Hay, D.J. Southee and D.J. Harrison

Microcontact printing is a process used to print high‐resolution protein arrays for biosensors. The paper aims to investigate using these techniques to print electrically…

Abstract

Purpose

Microcontact printing is a process used to print high‐resolution protein arrays for biosensors. The paper aims to investigate using these techniques to print electrically conductive fine line structures for electroluminescent (E/L) light sources.

Design/methodology/approach

The viability of using microcontact printing as a process for electronics fabrication is investigated. Polydimethylsiloxane stamps inked with alkanethiol compounds form self‐assembled monolayers on substrate surfaces, acting as the resist to subsequent etching processes. The printed lines are characterized with regard to their performance as high‐electric field generators in electroluminescent displays.

Findings

It has been demonstrated that microcontact printing is a cheap, repeatable process for fabricating electronic devices. The results demonstrate the viability of the process to fabricate electric field generator structures for E/L light sources with reduced driving voltages.

Originality/value

The paper demonstrates that microcontact printing can produce electrically conductive fine‐line structures with high resolution, confirming its viability in printed electronics manufacture.

Details

Circuit World, vol. 34 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 5 May 2015

Jagdeep S. Sagu, Nicola York, Darren Southee and K.G.U. Wijayantha

The purpose of this paper is to report on the feasibility of the manufacture of printed rechargeable power sources incorporating, in the first instance, electrode structures from…

Abstract

Purpose

The purpose of this paper is to report on the feasibility of the manufacture of printed rechargeable power sources incorporating, in the first instance, electrode structures from the previous study, and moving on to improved electrode structures fabricated, via flexographic printing, using commercially available inks. It has been shown previously that offset lithography, a common printing technique, can be used to make electrodes for energy storage devices such as primary cells.

Design/methodology/approach

A pair of the original Ag/C electrodes, printed via offset lithography, were sandwiched together with a PVA-KOH gel electrolyte and then sealed. The resultant structures were characterised using electrochemical techniques and the performance as supercapacitors assessed. Following these studies, electrode structures of the same dimensions, consisting of two layers, a silver-based current collector covered with a high surface area carbon layer, were printed flexographically, using inks, on a melinex substrate. The characterisation and assessment of these structures, as supercapacitors, was determined.

Findings

It was found that the supercapacitors constructed using the offset lithographic electrodes exhibited a capacitance of 0.72 mF/cm2 and had an equivalent series resistance of 3.96 Ω. The structures fabricated via flexography exhibited a capacitance of 4 mF/cm2 and had an equivalent series resistance of 1.25 Ω The supercapacitor structures were subjected to bending and rolling tests to determine device performance under deformation and stress. It was found that supercapacitor performance was not significantly reduced by bending or rolling.

Originality/value

This paper provides insight into the use of printed silver/carbon electrodes within supercapacitor structures and compares the performance of devices fabricated using inks for offset lithographic printing presses and those made using commercially available inks for flexographic printing. The potential viability of such structures for low-end and cheap energy storage devices is demonstrated.

Details

Circuit World, vol. 41 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 December 2023

Zhe Du, Changjie Chen and Xinhou Wang

Stab-resistant body armor (SRBA) is used to protect the body from sharp knives. However, most SRBA materials currently have the disadvantages of large weight and thickness. This…

Abstract

Purpose

Stab-resistant body armor (SRBA) is used to protect the body from sharp knives. However, most SRBA materials currently have the disadvantages of large weight and thickness. This paper aims to prepare lightweight and high-performance SRBA by 3D printing truss structure and resin-filling method.

Design/methodology/approach

The stab resistance truss structure was prepared by the fused deposition modeling method, and the composite structure was formed after filling with resin for dynamic and quasi-static stab tests. The optimized structural plate can meet the standard GA68-2019. Digital image correlation technology was used to analyze the local strain changes during puncture. The puncture failure mode was summarized by the final failure morphologies. The explicit dynamics module in ANSYS Workbench was used to analyze the design of the overlapped structure stab resistance process in this paper.

Findings

The stab resistance performance of the 3D-printed structural plate is affected by the internal filling pattern. The stab resistance performance of 3D-printed structural parts was significantly improved after resin filling. The 50%-diamond-PLA-epoxy, with a thickness of only 5 mm was able to meet the stab resistance standard. Resins are used to increase the strength and hardness of the material but also to increase crack propagation and reduce the toughness of the material. The overlapping semicircular structure was inspired by the exoskeleton structure of the demon iron beetle, which improved the stab resistance between gaps. The truss structure can effectively disperse stress for toughening. The filled resin was reinforced by absorbing impact energy.

Originality/value

The 3D-printed resin-filled truss structure can be used to prepare high-performance stab resistance structural plates, which balance the toughness and strength of the overall structure and ultimately reduce the thickness and weight of the SRBA.

Article
Publication date: 1 August 2023

Dhinesh S.K. and Senthil Kumar Kallippatti Lakshmanan

The purpose of this study is to increasing the gauge factor, reducing the hysteresis error and improving the stability over cyclic deformations of a conductive polylactic acid…

Abstract

Purpose

The purpose of this study is to increasing the gauge factor, reducing the hysteresis error and improving the stability over cyclic deformations of a conductive polylactic acid (CPLA)-based 3D-printed strain sensor by modifying the sensing element geometry.

Design/methodology/approach

Five different configurations, namely, linear, serpentine, square, triangular and trapezoidal, of CPLA sensing elements are printed on the thermoplastic polyurethane substrate material individually. The resistance change ratio of the printed sensors, when loaded to a predefined percentage of the maximum strain values over multiple cycles, is recorded. Finally, the thickness of substrate and CPLA and the included angle of the triangular strain sensor are evaluated for their influences on the sensitivity.

Findings

The triangular configuration yields the least hysteresis error with high accuracy over repeated loading conditions, because of its uniform stress distribution, whereas the conventional linear configuration produces the maximum sensitivity with low accuracy. The thickness of the substrate and sensing element has more influence over the included angle, in enhancing the sensitivity of the triangular configuration. The sensitivity of the triangular configuration exceeds the linear configuration when printed at ideal sensor dimensional values.

Research limitations/implications

The 3D printing parameters are kept constant for all the configurations; rather it can be varied for improving the performance of the sensor. Furthermore, the influences of stretching rate and nozzle temperature of the sensing material are not considered in this work.

Originality/value

The sensitivity and accuracy of CPLA-based strain sensor are evaluated for modification in its geometry, and the performance metrics are enhanced using the regression modelling.

Details

Rapid Prototyping Journal, vol. 29 no. 9
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 June 1981

At the commencement of this decade, leaving behind the “striking seventies”, we christened it the “anxious eighties”, for there was a profound disquiet and uncertainty among most…

Abstract

At the commencement of this decade, leaving behind the “striking seventies”, we christened it the “anxious eighties”, for there was a profound disquiet and uncertainty among most of the population, a fear that things were going to get worse, but they could have hardly expected the catastrophic events of the year 1981. The criteria of quality of life are its richness, grace, elegance; by the promise it contains; inspiration and purpose, hope, determination (to survive, to make certain that the evildoer is not permitted to succeed), love of one's country — pro patria, of other days.

Details

British Food Journal, vol. 83 no. 6
Type: Research Article
ISSN: 0007-070X

Content available
Article
Publication date: 27 November 2007

J.H. Ling

251

Abstract

Details

Circuit World, vol. 33 no. 4
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 2 November 2015

Fulian Qiu and David Harrison

Wearable electronic devices have emerged which require compact, flexible power storage devices such as batteries and supercapacitors. Recently, energy storage devices have been…

Abstract

Purpose

Wearable electronic devices have emerged which require compact, flexible power storage devices such as batteries and supercapacitors. Recently, energy storage devices have been developed based on supercapacitor threads. However, current supercapacitor energy storage threads which use electrolytes based on aqueous gels have a 1 V potential window. This is much lower than the voltage required by most electronic devices. This current contribution presents an approach for fabricating a multilayer supercapacitor working as a circuit unit, in which series combinations of the multiple layer structures can achieve a higher potential window, which can better meet the needs of wearable electronic devices.

Design/methodology/approach

Two-capacitive layer thread supercapacitors were fabricated using a semi-automatic dip coating method by coating two capacitive layers sequentially on a 50 μm stainless steel core wire, each capacitive layer includes ink, aqueous-based gel electrolyte and silver conductive paint layers.

Findings

Two capacitive layers of the single thread supercapacitor can work independently, or as combination circuits – parallel and series. Cyclic voltammograms showed that all flexible circuits have high electrochemical stability. For the case of series circuit configuration, with H3PO-polyvinyl alcohol (PVA) gel electrolyte, a working potential window of 2 V was achieved.

Originality/value

A flexible single thread supercapacitor of multilayer structure, with working voltage above 1 V in H3PO4-PVA gel electrolyte, has not been reported before. A semi-automatic dip coating setup used to process the thread supercapacitor has high potential for transfer to an industrial environment for mass production.

Details

Circuit World, vol. 41 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 26 August 2014

Lynn Sudbury-Riley

– The purpose of this paper is to investigate the experiences of older consumers with a range of product packaging.

1941

Abstract

Purpose

The purpose of this paper is to investigate the experiences of older consumers with a range of product packaging.

Design/methodology/approach

The study uses qualitative diary research (QDR). Ten seniors recorded all their experiences with packaging over a two-week period. Using a frame narrative that views ageing as multidimensional, diary entries uncover rich data that goes beyond physical age-related issues.

Findings

In addition to physical problems with packaging, older adults experience psychological frustration and feelings of alienation. Social implications of dependence on others are also discovered, despite many being purchasers of up-market luxury products.

Research limitations/implications

The study is exploratory and due to its qualitative methodology findings cannot be generalised to the wider population. Nevertheless it provides a starting point for future research into packaging and senior consumers.

Practical implications

The study has implications for all managers who participate in planning and designing brand packaging and calls for them to work more closely with ergonomics and design professionals in order to better plan for the needs of a large and growing sector of the population.

Social implications

Findings suggest that the basic need to feed oneself is hampered by some packaging, which of course is detrimental to the quality of life of older adults.

Originality/value

Few studies consider packaging and older consumers and this is particularly true in the marketing literature. This is the first study to use QDR in this context, and as such has several advantages over recall studies. The study also makes a contribution to knowledge pertaining to vulnerable consumers.

Details

Marketing Intelligence & Planning, vol. 32 no. 6
Type: Research Article
ISSN: 0263-4503

Keywords

Article
Publication date: 25 January 2011

Sari Merilampi, Toni Björninen, Leena Ukkonen, Pekka Ruuskanen and Lauri Sydänheimo

The purpose of this paper is to develop a wireless strain sensor for measuring large strains. The sensor is based on passive ultra high‐frequency radio frequency identification…

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Abstract

Purpose

The purpose of this paper is to develop a wireless strain sensor for measuring large strains. The sensor is based on passive ultra high‐frequency radio frequency identification (RFID) technology and it can be embedded into a variety of structures.

Design/methodology/approach

Silver ink conductors and RFID tags were printed by the screen printing method on stretchable polyvinyl chloride and fabric substrates. The development of the strain‐sensitive RFID tag was based on the behavior of the selected antenna and substrate materials. Performance of the tags and the effect of mechanical strain on tag functioning were examined.

Findings

The results showed that large displacements can be successfully measured wirelessly using a stretchable RFID tag as a strain‐sensitive structure. The behavior of the tag can be modified by selection of the material.

Research limitations/implications

New tag designs, which are more sensitive to small levels of strain and which have a linear response will be the subject for future work. Tag performance under cyclic loading and in a real environment will also be investigated. Future work relating the investigation of practical applications and the system designing for the strain sensor will also be required.

Practical implications

Printing is fast and simple manufacturing process which does not produce much waste or material loss. The sensor is a new application of printed electronics. It also provides new opportunities for system designers.

Originality/value

The paper provides a new kind of wireless strain sensor which can be integrated into many structures (i.e. clothes). The sensor is a new application of printed electronics and it is made from novel materials.

Details

Sensor Review, vol. 31 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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