Reviews

The Hutchinson Electronic Encyclopedia, First Electronic Version, Oxford, Random Century and Attica Cybernetics, 1991. ISBN: 1–873472–00–5. Price £99

Bridging the gap: rewritable electronics using real-time light-induced dielectrophoresis on lithium niobate

In the context of micro-electronics, the real-time manipulation and placement of components using optics alone promises a route towards increasingly dynamic systems, where the geometry and function of the device is not fixed at the point of fabrication. Here, we demonstrate physically reconfigurable circuitry through light-induced dielectrophoresis on lithium niobate. Using virtual electrodes, patterned by light, to trap, move, and chain individual micro-solder-beads in real-time via dielectrophoresis, we demonstrate rewritable electrical contacts which can make electrical connections between surface-bound components. The completed micro-solder-bead bridges were found to have relatively low resistances that were not solely dominated by the number of interfaces, or the number of discrete beads, in the connection. Significantly, these connections are formed without any melting/fusing of the beads, a key feature of this technique that enables reconfigurability. Requiring only a low-power (~3.5 mW) laser source to activate, and without the need for external power supply or signal generation, the all-optical simplicity of virtual-electrodes may prove significant for the future development of reconfigurable electronic systems

Ultrafast optical manipulation of atomic arrangements in chalcogenide alloy memory materials

A class of chalcogenide alloy materials that shows significant changes in optical properties upon an amorphous-to-crystalline phase transition has lead to development of large data capacities in modern optical data storage. Among chalcogenide phase-change materials, Ge2Sb2Te5 (GST) is most widely used because of its reliability. We use a pair of femtosecond light pulses to demonstrate the ultrafast optical manipulation of atomic arrangements from tetrahedral (amorphous) to octahedral (crystalline) Ge-coordination in GST superlattices. Depending on the parameters of the second pump-pulse, ultrafast nonthermal phase-change occurred within only few-cycles (~ 1 ps) of the coherent motion corresponding to a GeTe4 local vibration. Using the ultrafast switch in chalcogenide alloy memory could lead to a major paradigm shift in memory devices beyond the current generation of silicon-based flash-memory.Comment: 11 pages, 7 figures, accepted for publication in Optics Expres

Traceability system for capturing, processing and providing consumer-relevant information about wood products: System solution and its economic feasibility

Current research and practice reports indicate the existence of purchase barriers concerning eco-friendly products, e.g. wood products. These can be ascribed to consumers' mistrust regarding the non-observable environmental impact of wood products. To counter the mistrust, wood products are commonly endowed with eco-labels, which may be perceived mostly as a marketing tool, therefore not fulfilling their intended purpose. Current studies have shown that providing consumers with wood product information based on traceability systems increases product trust and purchase intentions, with those information items most valued by consumers being identified as well. Based on this, the paper proposes a traceability information system for the capturing, processing, and provision of product information using examples of wood furniture. Furthermore, a cost-benefit model for the proposed solution is developed. The calculations indicate the possibility of implementing traceability at the item level based on a four-layer system architecture enabling the capture and delivery of all information valued by consumers at acceptable costs. The proposed system helps to overcome purchase barriers of eco-friendly products, increasing consumers' product trust and purchase intentions

Inkjet Printing of Functional Electronic Memory Cells: A Step Forward to Green Electronics

open access journalNowadays, the environmental issues surrounding the production of electronics, from the perspectives of both the materials used and the manufacturing process, are of major concern. The usage, storage, disposal protocol and volume of waste material continue to increase the environmental footprint of our increasingly “throw away society”. Almost ironically, society is increasingly involved in pollution prevention, resource consumption issues and post-consumer waste management. Clearly, a dichotomy between environmentally aware usage and consumerism exists. The current technology used to manufacture functional materials and electronic devices requires high temperatures for material deposition processes, which results in the generation of harmful chemicals and radiation. With such issues in mind, it is imperative to explore new electronic functional materials and new manufacturing pathways. Here, we explore the potential of additive layer manufacturing, inkjet printing technology which provides an innovative manufacturing pathway for functional materials (metal nanoparticles and polymers), and explore a fully printed two terminal electronic memory cell. In this work, inkjetable materials (silver (Ag) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)) were first printed by a piezoelectric Epson Stylus P50 inkjet printer as stand-alone layers, and secondly as part of a metal (Ag)/active layer (PEDOT:PSS)/metal (Ag) crossbar architecture. The quality of the individual multi-layers of the printed Ag and PEDOT:PSS was first evaluated via optical microscopy and scanning electron microscopy (SEM). Furthermore, an electrical characterisation of the printed memory elements was performed using an HP4140B picoammeter

Rewritable Photonic Integrated Circuits Using Dielectric-assisted Phase-change Material Waveguides

Photonic integrated circuits (PICs) have the potential to drastically expand the capabilities of optical communications, sensing, and quantum information science and engineering. However, PICs are commonly fabricated using selective material etching, a subtractive process. Thus, the chip's functionality cannot be substantially altered once fabricated. Here, we propose to exploit wide-bandgap non-volatile phase-change materials (PCMs) to create a rewritable PIC platform. A PCM-based PIC can be written using a nano-second pulsed laser without removing any material, akin to rewritable compact disks. The whole circuit can then be erased by heating, and a completely new circuit can be rewritten. We designed a dielectric-assisted PCM waveguide consisting of a thick dielectric layer on top of a thin layer of wide-bandgap PCMs Sb2S3 and Sb2Se3. The low-loss PCMs and our engineered waveguiding structure lead to a negligible optical loss. Furthermore, we analyzed and specified the spatio-temporal laser pulse shape to write the PCMs. Our proposed platform will enable low-cost manufacturing and have a far-reaching impact on the rapid prototyping of PICs, validation of new designs, and photonic education

Mass storage technologies for libraries & information centres

To overcome growing requirements for additional space and for archival storage of less used, old and important documents, libraries have been using compact or dormitory storage and microfilming techniques. Of late, information technologies have come to their rescue. Many technologies-magnetic as well as optical have been tried for the past many years for mass storage of information. While magnetic drum and tape are, heading towards obsolescence, optical' technologies with their enormous storage capacities are trying to fill the gap. This paper overviews the various 'technologies available for mass storage in the library environment. The paper covers the magnetic storage devices including magnetic tape, magnetic disc, cartridge tape and digital audio tape. The optical disc storage technologies including read-only, write once read many and erasable/rewritable media have been described. The role of optical discs in making electronic publishing a popular technology has also been described. Future trends in the mass storage technologies like volume holographic technology, electronic trap and proximal probe technologies, and fluorescent multi-layered technology which are under various stages of development have also been briefly discussed. Applications of these technologies in library and information centres. have been listed

The Wiltshire Wills Feasibility Study

The Wiltshire and Swindon Record Office has nearly ninety thousand wills in its care. These records are neither adequately catalogued nor secured against loss by facsimile microfilm copies. With support from the Heritage Lottery Fund the Record Office has begun to produce suitable finding aids for the material. Beginning with this feasibility study the Record Office is developing a strategy to ensure the that facsimiles to protect the collection against risk of loss or damage and to improve public access are created.<p></p> This feasibility study explores the different methodologies that can be used to assist the preservation and conservation of the collection and improve public access to it. The study aims to produce a strategy that will enable the Record Office to create digital facsimiles of the Wills in its care for access purposes and to also create preservation quality microfilms. The strategy aims to seek the most cost effective and time efficient approach to the problem and identifies ways to optimise the processes by drawing on the experience of other similar projects. This report provides a set of guidelines and recommendations to ensure the best use of the resources available for to provide the most robust preservation strategy and to ensure that future access to the Wills as an information resource can be flexible, both local and remote, and sustainable