254 research outputs found

    A Rapid Photopatterning Method for Selective Plating of 2D and 3D Microcircuitry on Polyetherimide

    Get PDF
    In this work, a method for the rapid synthesis of metallic microtracks on polyetherimide is presented. The method relies on the photosynthesis of silver nanoparticles on the surface of the polymer substrates from photosensitive silver chloride (AgCl), which is synthesized directly on the polyetherimide surface. The study reveals that the use of AgCl as a photosensitive intermediate accelerates the reactions leading to the formation of silver nanoparticles by up to two orders of magnitude faster than other photodecomposition schemes. The patterning can be conducted under blue light, with notable advantages over UV exposure. Polymers of significant interest to the microelectronics and 3D printing industries can be directly patterned by light using this photography‐inspired technique at throughputs high enough to be commercially advantageous. Light exposures as short as a few seconds are sufficient to allow the direct metallization of the illuminated polyetherimide surface. The results show that the silver required for the seed layer is minimal, and the later copper electroless plating results in the selective growth of conductive tracks for circuitry on the light‐patterned areas, both on flexible films and 3D printed surfaces

    Direct metallisation of polyetherimide substrates by activation with different metals

    Get PDF
    This article reports the performance of different metallic ions and nanoparticles (Ag, Cu, Ni, Pd, Cr, Co, Au and Fe) used as seed layers, formed by chemical or optical reduction, for the electroless Cu plating of metal tracks onto polyetherimide (PEI). Plated Cu performance was tested by adhesion, electrical conductivity, plating rate, XPS, SEM, XRD and EDX analysis. The application of Cu and Ag seeds resulted in high quality electroless Cu deposits presenting strong adhesion properties and high conductivity ((2.0 ± 0.5) × 107 S/m and (3.6 ± 0.2) × 107 S/m, respectively) compared with bulk copper (5.96 × 107 S/m). Performance is attributed to the high surface density and uniformity of seed layers. Of the metals, only Ag ions were photoreduced under the conditions applied and were subsequently used to electroless Cu plate high quality track features of 150 μm width. The application of sulphuric acid pre-treatment to PEI prior to Ag ion exchange, improved the photoinitiated track formation process, as demonstrated by a threefold increase to both photoinduced Ag nanoparticle density on the surface and electroless Cu plating rate, as well as improved electroless Cu adhesion to PEI

    A rapid technique for the direct metallization of PDMS substrates for flexible and stretchable electronics applications

    Get PDF
    Metallization of a polydimethylsiloxane (PDMS)-based substrate is a challenge due to the difficulties in forming crack-free polymer and metal features using standard deposition techniques. Frequently, additional adhesion layers, rigid substrates, multiple processing steps (lift-off and etching) and expensive metal sputtering techniques are required, to achieve such metal patterns. This work presents a novel and rapid technique for the direct metallization of PDMS substrates using photolithography and electroless copper plating. The method has the advantage of not requiring expensive vacuum processing or multiple metallization steps. Electroless copper layer is demonstrated to have a strong adhesion to PDMS substrate with a high conductivity of (3.6 ± 0.7) × 107 S/m, which is close to the bulk copper (5.9 × 107 S/m). The copper-plated PDMS substrate displays mechanical and electrical stability whilst undergoing stretching deformations up to 10% due to applied strain. A functional electronic circuit was fabricated as a demonstration of the mechanical integrity of the copper-plated PDMS after bending

    3D virtual worlds as environments for literacy learning

    Get PDF
    Background: Although much has been written about the ways in which new technology might transform educational practice, particularly in the area of literacy learning, there is relatively little empirical work that explores the possibilities and problems - or even what such a transformation might look like in the classroom. 3D virtual worlds offer a range of opportunities for children to use digital literacies in school, and suggest one way in which we might explore changing literacy practices in a playful, yet meaningful context. Purpose: This paper identifies some of the key issues that emerged in designing and implementing virtual world work in a small number of primary schools in the UK. It examines the tensions between different discourses about literacy and literacy learning and shows how these were played out by teachers and pupils in classroom settings.Sources of evidence: Case study data are used as a basis for exploring and illustrating key aspects of design and implementation. The case study material includes views from a number of perspectives including classroom observations, chatlogs, in-world avatar interviews with teachers and also pupils, as well as the author’s field notes of the planning process with accompanying minutes and meeting documents.Main argument: From a Foucauldian perspective, the article suggests that social control of pedagogical practice through the regulation of curriculum time, the normalisation of teaching routines and the regimes of individual assessment restricts teachers’ and pupils’ conceptions of what constitutes literacy. The counternarrative, found in recent work in new litearcies (Lankshear & Knobel, 2006) provides an attractive alternative, but a movement in this direction requires a fundamental shift of emphasis and a re-conceptualisation of what counts as learning.Conclusions: This work on 3D virtual worlds questions the notion of how transformative practice can be achieved with the use of new technologies. It suggests that changes in teacher preparation, continuing professional development as well as wider educational reform may be needed

    The views of five participating undergraduate students of the Student Associates Scheme in England

    Get PDF
    This paper reports findings from a study which explored undergraduate perceptions of the Student Associates Scheme in England (SAS). The scheme was established by the Training and Development Agency for Schools in an attempt to increase the number of graduates entering the teaching profession, particularly in shortage subjects such as the physical sciences and mathematics. The scheme places undergraduate students on short-term placements in secondary schools throughout England to provide them with experiences that may encourage them to consider teaching as a career option. Findings show that the SAS school placements were a positive experience for the students participating in this study. However, a question emerged as to whether or not the scheme is targeting students who have yet to decide upon teaching as a career or just reinforcing the existing aspirations of students who have already decided to teach. As the scheme is attempting to increase the number of teachers entering the profession this question has important implications for this study and further work which will focus on undergraduates who think that their career ambitions would not be fulfilled by teaching

    Pre-service teachers’ engagement in a cross-curricular television news project: impact on professional identity

    Get PDF
    This paper focuses on the impact of pre-service teachers’ engagement in the annual BBC News School Report project on their emerging professional identity and on the evidence they provide as part of the process of becoming qualified. The research reported on is drawn from three years of enquiry. Respondents included pre-service teachers themselves, their tutors as representatives of teacher education providers and their mentors as representatives of schools in which they were placed. The methodological approach was interpretative and phenomenological with qualitative and quantitative data being analysed for emergent themes. Two years of evaluations were followed by a third year in which a set of case studies were developed. The research showed that professional identity is enhanced through being in a leading role in respect of curriculum and working with other staff. Through engagement in such projects, this paper moots that preservice teachers develop richer evidence of emerging professionalism as defined by standards of initial teacher training. Moreover, self-perception of role was modified to one in which they saw themselves, and were seen, as equals to qualified staff rather than subservient to or dependent on them. A new more equal power relationship developed as they took on responsibility for the project. Preservice teachers’ move to become full members of the professional community for which they are training was accelerated

    Improving the professional knowledge base for education: Using knowledge management (KM) and Web 2.0 tools

    Get PDF
    Improving education systems is an elusive goal. Despite considerable investment, international studies such as the OECD Teaching and Learning International Survey (TALIS) project and the McKinsey Report How the world’s best performing schools come out on top indicate that improving teacher quality is more important than increased financial investment. Both reports challenge governments, academics and practitioners to adopt new ways of sharing and building knowledge. This paper makes the case for national education systems to adopt tried and tested knowledge management and web 2.0 tools used by other sectors and highlights the neglected potential of teacher educators as agents for improvement
    corecore