Printing Conductive Paths for Electronic Functional Devices

Printing inorganic and organic materials has been attracting plenty of researchers and scientists as an alternative to the conventional photolithography and electroless deposition methods due to the complications, time-consuming, size restrictions and high costs that these methods usually experience. Soft lithographic techniques and inkjet printing technology have offered simpler, lower costs and faster alternatives. One of the main objectives of this study is the contribution to these alternatives by utilising a cost-effective, simple and easy-to-use stamp printing machine in the deposition of metal patterns from poly(dimethylsiloxane) (PDMS) stamps onto treated glass substrates. Two drop-on-demand inkjet printers; one is a commercial desktop piezoelectric printer and a second thermal PEL printing and coating platform, were utilised to inkjet print functional materials. The cheap piezoelectric one used to deposit silver nanoparticles and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) inks. By utilising this technology, innovative flexible information storage devices, electronic memory cells, were inkjet printed. All the components (silver electrodes and PEDOT:PSS active layer) of these memory devices were fully deposited by this simple desktop inkjet printer on a flexible substrate (ceramic coated PEL paper) at room temperature. The thermal printing machine, on the other hand, was employed to print graphene oxide on the PEL paper. These techniques also provide hope to develop environmentally friendly processes of fabrication used in the electronics and semiconductor industry and minimise the wastage of materials and power

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

3D Printing of Flexible Two Terminal Electronic Memory Devices

Recent strategy in the electronics sector is to ascertain the ways to make cheap, flexible and environmentally friendly electronic devices. The 3D Inkjet printing technology is based on the Additive Manufacturing concept [1] and it is with no doubt capable of revolutionizing the whole system of manufacturing electronic devices including: material selection; design and fabrication steps and device configuration and architecture. 3D Inkjet printing technology (IJP) is one of the most promising technologies to reduce the harmful radiation/ heat generation and also achieve reduction in manufacturing cost. Here, we explore the potential of 3D – inkjet printing technology to provide an innovative approach for electronic devices in especially information storage elements by seeking to manufacture and characterize state-of-art fully inkjet printed two terminal electronic memory devices. In this work, an ink-jettable material was formulated, characterized and printed by a a piezoelectric Epson Sylus P50 Inkjet printing machine on a flexible substrate. The active printed layers were deposited into a functioning simple metal/insulator/metal structure. Firstly, from ink perspective, the main physical properties such as rheological behaviour; surface tension and wettability were investigated. Furthermore, an in-depth electrical characterization of the fabricated memory cells was carried out using HP4140B picoammeter and an HP4192A impedance analyser. [1] N.Hopkinson, R.Hague, P.Dickens, Rapid manufacturing; an industrial revolution for the digital age. West Sussex, UK, John Wiley and Sons; 2006 [2] Iulia Salaoru, Zuoxin Zhou, Peter Morris, Gregory Gibbons, Inkjet printing of polyvinyl alcohol multilayers for addiive manufacturing applications, J.Appl.Polym.Sci., 133(25), 43572 (2016) [3] Ruth Cherrington, B.M.Wood, Iulia Salaoru, Vannessa Goodship, Digital printing of titanium dioxide for dye sensitized solar cells, JoVE, e53963, (2016) [4] Iulia Salaoru, Zuoxin Zhou, Peter Morris, Gregory J. Gibbons, Inkjet-printed Polyvinyl Alcohol Multilayers, JoVE,123, e55093-e55093, (2017)