Search results

1 – 8 of 8
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: 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: 13 February 2007

Darren Southee, Gareth I. Hay, Peter S.A. Evans and David J. Harrison

It has been shown that circuit interconnects and various passive components can be fabricated on a variety of flexible substrates using the offset lithographic process. This paper…

Abstract

Purpose

It has been shown that circuit interconnects and various passive components can be fabricated on a variety of flexible substrates using the offset lithographic process. This paper reports on a feasibility study investigating the manufacture of voltaic cells deposited via offset lithography.

Design/methodology/approach

The Leclanché cell, an established battery chemistry, was chosen as an appropriate technology for adaptation to the offset lithographic process. Development of inks with appropriate rheological properties for lithographic printing was undertaken. Zinc and carbon electrodes were fabricated with silver‐based current collectors. Electrolyte composition was investigated along with separator materials.

Findings

Zinc and carbon‐based inks have been produced which result in deposited material appropriate for use as electrodes. A separator material soaked in electrolyte has been combined with these electrode structures and an MnO2 paste to form a voltaic cell. A printed battery, made up of these voltaic cells, with a capacity greater than 8 mAh at 6 V has been produced.

Originality/value

The fabrication of voltaic cells via offset lithography facilitates the production of electronic systems with power sources provided by the same printing process. This paper provides information of interest to all those involved in the developing industry of printed and flexible electronics.

Details

Circuit World, vol. 33 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Content available
Article
Publication date: 16 May 2008

Martin Goosey

79

Abstract

Details

Circuit World, vol. 34 no. 2
Type: Research Article
ISSN: 0305-6120

Content available
Article
Publication date: 17 April 2007

Dr Darren Cadman

84

Abstract

Details

Soldering & Surface Mount Technology, vol. 19 no. 2
Type: Research Article
ISSN: 0954-0911

Content available
Article
Publication date: 14 September 2012

Martin Goosey

268

Abstract

Details

Soldering & Surface Mount Technology, vol. 24 no. 4
Type: Research Article
ISSN: 0954-0911

Content available
Article
Publication date: 13 February 2007

Martin Goosey

48

Abstract

Details

Circuit World, vol. 33 no. 1
Type: Research Article
ISSN: 0305-6120

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

1 – 8 of 8