Inkjet4Tex: Creative implications of 3D inkjet printing technologies for textiles

This project expands future applied-design capabilities for textiles as a function of inkjet deposition technology. The project investigates 3D inkjet rapid-production tools’ potential, focusing on creative gaps in the developing technology in its application to the textile design process. As such, the research investigates future design possibilities for inkjet printing technology in the creation of 3D textile structures and surfaces. The research “demonstrates how tacit knowledge can be employed, observed and created in a methodical way, with new artefacts playing a role in provoking insights based on tacit understanding”… [with a ] focus on developing and employing tacit insights that would not be revealed in situations where nothing has been changed.” (Rust, 2007) As inkjet textile technology evolves past a rapid prototyping tool into a series of responsive manufacturing techniques for textile products, designers, textile technology developers and soft goods industries will be able to use the results of this research to maximize their creative development. By developing and employing modified 2D/3D textile design processes with the technology future creators will be assisted to conceptualise and manufacture locally, creatively and with more accessible technologies. Keywords: 3D textiles, surface design, technology-driven design process, inkjet printing, fused deposition modelling, novel textile design</p

Towards inkjet-printed low cost passive UHF RFID skin mounted tattoo paper tags based on silver nanoparticle inks

The present work describes the inkjet printing and low temperature sintering of silver nanoparticle inks onto transfer tattoo paper. Our approach results in silver features of excellent resolution and conductivity and, subsequently the first passive UHF RFID transfer tattoo tags functional mounted on human skin of improved performance when compared to screen printed passive UHF RFID transfer tattoo paper tags. Moreover, inkjet printed passive UHF RFID transfer tattoo tags show similar performance to copper etched passive UHF RFID tags on plastic substrates. This study compares the image quality (resolution) and electrical performance of two commercial silver nanoparticle inks inkjet printed on transfer tattoo paper. The optimal printing and sintering parameters to obtain high resolution features of resistivities 20 to 57 times the resistivity of bulk silver (1.59 × 10?6 ohm cm) are described. We demonstrate how, by selectively depositing ink in specific areas of the antenna, read distance of passive UHF RFID tags can be increased from 54 to 68 cm whilst decreasing the amount of ink used by 33%. Furthermore, this approach results in inkjet printed passive UHF RFID tattoo tags with larger read distance than silver screen printed passive UHF RFID tattoo tags, 45 cm, and similar to copper etched passive UHF RFID plastic tags, 75 cm. Moreover, inkjet printed passive UHF RFID tattoo tags in this work are considerably thinner (1–5 ?m) than screen and etched passive UHF RFID tags (tens of micrometers) hence, making the former more appealing to the end user. In addition to this, inkjet printing is compatible with large area manufacturing techniques and has the potential to evolve as one of the most promising RFID mass-production techniques. Therefore, this work represents a step towards the commercialization of on-body transfer tattoo paper passive UHF RFID tags

Potential up-scaling of inkjet-printed devices for logical circuits in flexible electronics

Inkjet Technology is often mis-believed to be a deposition/patterning technology which is not meant for high fabrication throughput in the field of printed and flexible electronics. In this work, we report on the 1) printing, 2) fabrication yield and 3) characterization of exemplary simple devices e.g. capacitors, organic transistors etc. which are the basic building blocks for logical circuits. For this purpose, printing is performed first with a Proof of concept Inkjet printing system Dimatix Material Printer 2831 (DMP 2831) using 10 pL small print-heads and then with Dimatix Material Printer 3000 (DMP 3000) using 35 pL industrial print-heads (from Fujifilm Dimatix). Printing at DMP 3000 using industrial print-heads (in Sheet-to-sheet) paves the path towards industrialization which can be defined by printing in Roll-to-Roll format using industrial print-heads. This pavement can be termed as "Bridging Platform". This transfer to "Bridging Platform" from 10 pL small print-heads to 35 pL industrial print-heads help the inkjet-printed devices to evolve on the basis of functionality and also in form of up-scaled quantities. The high printed quantities and yield of inkjet-printed devices justify the deposition reliability and potential to print circuits. This reliability is very much desired when it comes to printing of circuits e.g. inverters, ring oscillator and any other planned complex logical circuits which require devices e.g. organic transistors which needs to get connected in different staged levels. Also, the up-scaled inkjet-printed devices are characterized and they reflect a domain under which they can work to their optimal status. This status is much wanted for predicting the real device functionality and integration of them into a planned circuit

Inkjet printed LED based pH chemical sensor for gas sensing

Predictable behaviour is a critical factor when developing a sensor for potential deployment within a wireless sensor network (WSN). The work presented here details the fabrication and performance of an optical chemical sensor for gaseous acetic acid analysis, which was constructed using inkjet printed deposition of a colorimetric chemical sensor. The chemical sensor comprised a pH indicator dye (bromophenol blue), phase transfer salt tetrahexylammonium bromide and polymer ethyl cellulose dissolved in 1-butanol. A paired emitter-detector diode (PEDD) optical detector was employed to monitor responses of the colorimetric chemical sensor as it exhibits good sensitivity, low power consumption, is low cost, accurate and has excellent signal to noise ratios. The chemical sensor formulation was printed directly onto the surface the emitter LED, and the resulting chemical sensors characterised with respect to their layer thickness, response time and recovery time. The fabrication reproducibility of inkjet printed chemical sensors in comparison to drop casted chemical sensors was investigated. Colorimetric chemical sensors produced by inkjet printing, exhibited an improved reproducibility for the detection of gaseous acetic acid with a relative standard deviation of 5.5 % in comparison to 68.0 % calculated for drop casted sensors (n = 10). The stability of the chemical sensor was also investigated through both intra and inter-day studies

A comparative study of two conductive inkjet inks for fabrication of RF circuit structures

Two commercially available silver inks were inkjet printed to fabricate the seed tracks (seed layers) of radio frequency (RF) circuit structures on a high frequency substrate material. One of them is a nanoparticle based ink, and the other, a non-particle based organic silver complex ink. Subsequent to printing, these seed layers were copper plated using an electroless copper plating process, to impart the desired thickness to the circuit structures. The inkjet printing-electroless plating process combination was validated with the example of an S-band filter and an RF transmission line. Prior to the fabrication of the circuit structures, the substrates were plasma treated, in order to modify their surface and promote mechanical interlocking with the printed structures.\ud Finally, experiments were conducted to determine the solderability\ud of inkjet printed as well as printed-plated structures. Conclusions on\ud the suitability of the two inks for RF circuit fabrication have been\ud drawn based on experimental results

Surface Modification of a PCB Substrate for Better Adhesion of Inkjet Printed Circuit Structures

The robustness and service life of inkjet printed electronic circuit structures are highly influenced by the state of the interface between these structures and the substrate. In the case of polymeric substrate materials, surface modification is necessary to realise a favourable interface, as these materials are generally not very receptive to chemical bond formation with the deposited ink. This paper deals with the surface modification of a high frequency laminate (substrate) using two different techniques to improve interfacial adhesion. The techniques deployed are CF4/O2 based plasma treatment and micro structuring using pulsed laser. The plasma treatment parameters were varied systematically using a statistical design of experiments. Substrates with varying surface characteristics, resulting from different plasma treatment parameters, were subjected to post-processing steps including surface energy and surface roughness measurements. Similarly, the influence of laser treatment parameters on surface characteristics of the substrate was also studied in detail. The outcomes of these two surface modification techniques are discussed in this paper

Effect of conductive area trimming on the read range of inkjet printed Epidermal RFID tags

The effect of reducing the volume of conductive ink used in the fabrication of Epidermal RFID tags on the read range of the tag is investigated in this paper. The ink usage reduction is achieved by redesigning of the conductive parts of the designed tag

A feasibility study on using inkjet technology, micropumps, and MEMs as fuel injectors for bipropellant rocket engines

Control over drop size distributions, injection rates, and geometrical distribution of fuel and oxidizer sprays in bi-propellant rocket engines has the potential to produce more efficient, more stable, less polluting rocket engines. This control also offers the potential of an engine that can be throttled, working efficiently over a wide range of output thrusts. Inkjet printing technologies, MEMS fuel atomizers, and piezoelectric injectors similar in concept to those used in diesel engines are considered for their potential to yield a new, more active injection scheme for a rocket engine. Inkjets are found to be unable to pump at sufficient pressures, and have possibly dangerous failure modes. Active injection is found to be feasible if high pressure drop along the injector plate are used. A conceptual design is presented and its basic behavior assessed

Possibilities of Fabricating Copper-based RFID Tags with Photonic-sintered Inkjet Printing and Thermal Transfer Printing

This letter studies the possibilities of manufacturing copper-based passive UHF RFID tags using inkjet and thermal printing on two substrate materials, polyimide (Kapton) and a polyester based substrate (Flexcon THERMLfilm). Both printing methods are tested to fabricate different tag designs, and the performance of successfully printed tags is evaluated using wireless measurements. Measurement results show that both the printing methods, while using copper material, can be used to effectively fabricate passive UHF RFID tag antennas on selected substrates