Darren J. Southee

Lithographically printed voltaic cells – a feasibility study

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 Leclanche 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 ...

Meeting the expectation of industry: an integrated approach for the teaching of mechanics and electronics to design students

This paper examines the traditional engineering-based provision delivered to Product Design and Technology (B.Sc.) undergraduates at the Loughborough Design School and questions its relevancy against the increasing expectations of industry. The paper reviews final-year design projects to understand the level of transference of engineering-based knowledge into design practice and highlights areas of opportunity for improved teaching and learning. The paper discusses the development and implementation of an integrated approach to the teaching of Mechanics and Electronics to formalise and reinforce the key learning process of transference within the design context. The paper concludes with observations from the delivery of this integrated teaching and offers insights from student and academic perspectives for the further improvement of engineering-based teaching and learning.

Fabrication and characterisation of energy storage fibres

Fibre supercapacitors were designed and manufactured using a dip coating method. Their electrochemical properties were characterised using a VersaSTAT 3 workstation. Chinese ink with a fine dispersion of carbon and binder was coated as the electrode material. The specific capacitance per unit length of a copper fibre supercapacitor with the length of 41 cm reached 34.5 mF/cm. When this fibre supercapacitor was bent on rods with a diameter of 10.5 cm, the specific capacitance per length was 93% of the original value (without bending). It proved that these fibre supercapacitors have a good flexibility and energy storage capacity.

Wind farm and fauna interaction: detecting bird and bat wing beats through cyclic motion analysis

Recent Government announcements have implied that wind power will play a major part in providing energy for the UK (BBC 2007). However, there is much concern that wind farms can have a significant impact on flying fauna (bats and birds) using the area, particularly at night. As part of an Environmental Impact Assessment, thorough appropriate surveys are necessary for quantifying and minimising any risk wind farms may cause flying fauna. Manual surveys that are commonly used are not always cost‐effective, efficient or practical. Remote systems based on motion detection are increasingly being used to monitor wildlife. Fast‐moving airborne targets such as aeroplanes can falsely trigger motion‐detection based remote systems. As birds and bats repetitively flap their wings, this oscillating motion can be used to distinguish them from other airborne targets. Time periods between wing oscillations are not always constant, and hence the motion is not periodic. A method to detect cyclic motion based on similarity matrices is proposed, and synthetic and real data are used.

Human factors in the design of medical devices - Approaches to meeting international standards in the European Union and USA

This paper focuses on the challenges of meeting agency requirements as it pertains to the application of human factors in the medical device development (MDD) process. Individual case studies of the design and development process for 18 medical device manufacturers located in the US and EU were analyzed and compared using a multiple case study design. The results indicate that there are four main challenges in implementing international standards. These include a lack of direct access to users for the purposes of device development; a lack of understanding by users with regards to the impact of their feedback on the development process; contract formalities limiting user exchanges; and the attitude of clinical users directly impacting on the device developers invitation to participate in the development processes. The barriers presented in this research have the potential to be resolved but only with greater commitment by both medical device users and developers.

Aerosol-assisted fabrication of tin-doped indium oxide ceramic thin films from nanoparticle suspensions

Sn-doped In2O3 (ITO) thin films were fabricated on float glass substrates from a nanoparticle suspension using a new and inexpensive aerosol-assisted chemical transport (AACT) process. The influence of the solvent type, loading level and film deposition time on the structural, electrical and optical properties of the deposited thin films was investigated. In addition, the effect of the post-deposition heat-treatment of ITO films on the film resistivity and transparency was investigated using microwave radiation and compared with more conventional radiant heat-treated films. The SEM images of the films prepared using a 30 min deposition time with 0.20% (wt/vol%) methanolic ITO suspension provided better surface coverage compared to the other deposition times investigated. The optimised ITO films were heat-treated after deposition by either conventional radiant or microwave assisted heating methods in order to improve the inter-particle connections and film adherence. The films heat-treated after deposition by microwave annealing exhibited an average transmittance of >85% in the visible region with a resistivity of 12 Ω cm and a carrier concentration of −3.7 × 1016 cm3, which were superior to films that were heat-treated using more conventional thermal processing (despite the shorter processing time for the microwave process). The resistivity of ITO films was further decreased to 6.0 × 10−2 Ω cm with an increased carrier concentration of −8.0 × 1018 cm3 when ethyl cellulose was added to the ITO suspension prior to the AACT deposition. The enhanced conductivity of this film is due to the improved particle–particle and particle–substrate connections as observed by SEM imaging.

Towards a Design Process Ontology

ABSTRACT In the absence of any single coherent all-encompassing theoretical model of designing, this study seeks to review and rationalize theories of design process as the foundational framework for exploring where value is added through design. This leads to an interim design process ontology, or more simply; a terminological framework which can accommodate the significant developments in design process modelling of the last 50 years alongside identification of other significant factors which affect design outcomes. Within the resulting ontology class hierarchy, design process is placed within the wider context of design domain and an Input-Process-Output classification. Within the Process class, Motivation, Scale, Path and Design Process Structures are identified as significant subclasses. Research challenges resulting from the interim design ontology are identified.

Flexible dot-matrix display manufacture by offset lithography

Novel thermochromic graphic displays manufactured by printing thermochromic ink films in conjunction with conductive lithographic films (CLFs) are presented. Work in formulating lithographic printing inks is described. The properties of the deposited ink films and demonstration display structures employing these materials are discussed. These low-cost printed structures could be incorporated in the manufacture of electronic systems with integrated printed power sources affording environmental benefits when compared with conventional manufacturing techniques.

A study of the electrochemical performance of strip supercapacitors under bending conditions

The European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 281063

Fabrication and characterization of smart fabric using energy storage fibres

Fibre supercapacitors were designed and manufactured using a dip-coating method. Their electrochemical properties were characterized using a VersaSTAT 3 workstation. Chinese ink with a fine dispersion of carbon and binder was coated as the electrode material. The specific capacitance per unit length of a copper fibre supercapacitor with the length of 41 cm reached 34.5 mF/cm. When this fibre supercapacitor was bent on rods with a diameter of 10.5 cm, the specific capacitance per length was 93% of the original value (without bending). It showed that these fibre supercapacitors have good flexibility and energy storage capacity. Furthermore, the fibre supercapacitor in the fabric showed the same capacitance before and after weaving.