A survey of inkjet-printed low-cost sensors

2018 ◽  
Vol 85 (7-8) ◽  
pp. 504-514
Author(s):  
Christoph Beisteiner ◽  
Bernhard G. Zagar

Abstract Inkjet-printers from the company Epson and others can be used to fabricate low-cost sensors on coated PET films. By using nanoparticle-based dispersions resistive temperature dependent sensors, strain gauges, thermocouples and pressure sensors can be fabricated. For these purposes the gauge factors, Seebeck coefficients and temperature coefficients of resistance for Ag, Carbon Black and PEDOT:PSS dispersions on Mitsubishi® and Pelikan® PET substrates are characterized. Furthermore, piezoresistive effects in transverse and longitudinal strain directions are discussed. Additionally, a printed sensor system for measuring strains within a surface is presented. Finally, an injection-moulding process and a lamination process are used to improve the mechanical scratching of those sensors.

2013 ◽  
Vol 748 ◽  
pp. 544-548 ◽  
Author(s):  
Nik Mizamzul Mehat ◽  
Shahrul Kamaruddin ◽  
Abdul Rahim Othman

This paper presents the original development of an experimental approach in studying the multiple tensile characterizations as key quality characteristics for several different plastic gear materials related to various parameters in injection moulding process. In this study, emphases are given on a new low-cost mechanism for the testing of the injection moulded plastic spur gear specimens with various teeth module. The testing fixture are developed and validated to provide uniform state of tension with series of plastic gear specimens produced in accordance with the systematically designed of experiment. The effects of changes in the process parameters including melt temperature, packing pressure, packing time and cooling time at three different levels on the elongation at break and ultimate strength of plastic gear is evaluated and studied through the proposed experimental approach.


2013 ◽  
Vol 569-570 ◽  
pp. 751-758 ◽  
Author(s):  
Inka Buethe ◽  
Claus Peter Fritzen

The employment of a large number of embedded sensors in advanced monitoring systems becomes more common, enabling in-service detection, localization and assessment of defects in mechanical, civil and aerospace structures. These sensors could be optical fibre sensors, accelerometers, strain gauges or piezoelectric wafer active sensors (PWAS). As the latter are quite popular, due to its multipurpose application as actuators and sensors and its low cost, this type will be investigated. Within this paper a possible approach of sensor performance is presented. The method uses the coupled electro-mechanical admittance to detect damage of the PWAS and its bonding layer. The help of a temperature dependent theoretical model provides for influences of changing environmental and operational conditions. The model will be compared with FEM-results, before showing the successful application on experimental results.


2013 ◽  
Vol 747 ◽  
pp. 575-578 ◽  
Author(s):  
S. Arun ◽  
S. Kanagaraj

The usage of polymers is increased in order to replace the conventional metals because of their low cost and weight. As the processing technique of polymers plays a vital role in their properties, Polypropylene (PP) and multi walled carbon nanotubes (MWCNTs) were chosen as a matrix and reinforcement, respectively in order to confirm the effective processing method to prepare nanocomposites. The PP/MWCNTs nanocomposites with different concentration of reinforcement such as 0, 0.5, 1.0, 1.5 and 2.0 wt. % were prepared by melt mixing technique through (i) an injection molding (IM) process and (ii) the twin-screw extruder followed by an injection moulding process (TSE). It is observed that the mechanical properties of PP were found to be increased with MWCNTs concentration irrespective of the processing methods, where the optimum concentration was observed to be 1.5 wt. % of MWCNTs. It is also observed that the mechanical properties of polymer processed through TSE process was found to be less than that of the sample processed by IM process. However, an opposite trend was observed when the reinforcement was done. It is concluded that the PP/MWCNTs nanocomposites processed through TSE were found to have enhanced mechanical properties compared to that of the sample prepared through IM process.


Author(s):  
Gianluca Trotta ◽  
Vincenzo Bellantone ◽  
Rossella Surace ◽  
Irene Fassi

The increasing demand for small and even micro scale parts is boosting the development of reliable micro system technologies. Micro-fabrication process capabilities should expand to encompass a wider range of materials and geometric forms, by defining processes and related process chains that can satisfy the specific functional and technical requirements of new emerging multi-material products, and ensure the compatibility of materials and processing technologies throughout these manufacturing chains. Micro injection moulding is the process of transferring the micron or even submicron precision of microstructured metallic moulds to a polymeric products. It represents one of the key technologies for micro manufacturing because its mass production capability and relatively low production cost. Polymers have relatively low cost, and offer good mechanical and thermal strength, electrical insulation, optical transparency, chemical stability and biocompatibility. In this work the authors investigate the micro injection moulding process parameters on the overall quality of a miniaturized dog-bone shaped specimen. The aim of the experimentation is to calibrate the process and set the machine for the correct filling of the component. A set of injection parameters are selected for study by experimental plan and simulation tool and then discussed. Simulation results are used to better understand the polymer flow behaviour during the filling phase. A commercial software is used and input data, collected during the micro injection moulding process, are included using as performance indicators flow front position and moulded mass. Process simulation can provide, at the present time, mostly qualitative input to the designer and process engineer. Two different polymers materials are tested and evaluated in relation to the process replication capability: Polyoxymethylene (POM) and Liquid Cristal Polymer (LCP). Finally, the moulding factors with significant statistical effects are identified. The holding pressure and holding time for POM and the holding pressure and injection velocity for LCP show the highest influence on achieving high part mass.


Author(s):  
Vincenzo Bellantone ◽  
Rossella Surace ◽  
Francesco Modica ◽  
Irene Fassi

Due to its ability to produce low-cost and high repeatable micro polymeric parts, injection moulding of micro components is emerging as one of the most promising enabling technologies for the manufacturing of polymeric micro-parts in in many different fields, from IT to Healthcare, to Medicine. However, when approaching the micro-scale, different issues related to the process should be addressed, especially as the depth of the mould cavity becomes very thin. In particular, the mould roughness could affect the surface quality of the produced micro components, like in macro moulding, as well as the complete filling of the parts. Although micro-injection moulding process has been extensively studied, further research on the effect of mould roughness conditions and on non-Newtonian fluid flow in micro-cavities are required. This will shed a light and open up new paths for a deeper understanding of the moulding scenario. The main objective of the present paper is the evaluation of the influence of the mould roughness on the polymer flow during micro injection moulding process. The test parts have been realized in POM material and have thickness lower than 250 μm. The test part design has been properly conceived in order to neglect the effect of dimensions and geometry and to highlight the roughness contribution during the filling phase of micro injection moulding process. The experimentation has been performed considering cavities with different roughness values (3 levels) and decreasing depths (3 levels), for a total of nine test parts manufactured by micro-electrical discharge machining process (μ-EDM). The results of the experiments are discussed in the paper and show that cavity surface roughness affects the injection process as the moulding scale level is decreased. In particular, when the cavity depths are reduced, higher surface roughness promotes the filling of components and this finding could be ascribed to the increase of wall slip effect.


2017 ◽  
Vol 380 ◽  
pp. 212-217 ◽  
Author(s):  
C.A. Araújo Mota ◽  
C.J. Araújo ◽  
A.G. Barbosa de Lima ◽  
Tony Herbert Freire de Andrade ◽  
D. Silveira Lira

SMART materials have gained several applications in industries, especially aeronautical and biomedical. Therefore, the fabrication process of these materials must present quality in the completion and dimensioning, in addition to well established mechanical properties. In this sense, the Resin Transfer Molding (RTM) process is presented as an alternative to the manufacture of such products. This process presents advantages compared to other methods, such as, product quality and low cost. Thus, this work aims to model and simulate numerically the manufacturing process of polymer composite reinforced with NiTi shape memory alloy by RTM using the Ansys CFX commercial software. Results of pressure, velocity and volume fractions fields of the phases are presented and discussed. It was verified that the process parameters, like injection pressure and resin inlet and air outlet positions influenced the total time of the process and final product quality.


2013 ◽  
Vol 2013 (1) ◽  
pp. 000188-000193
Author(s):  
Teemu Alajoki ◽  
Matti Koponen ◽  
Arttu Huttunen ◽  
Markus Tuomikoski ◽  
Mikko Heikkinen ◽  
...  

Next generation of electronic modules and systems in different application areas such as automotive, medical and home appliances will utilize various electronic, optical and mechanical functions integrated in freeform intelligent products with benefits such as decreased volume and weight, lower costs and higher freedom of design when compared to currently available electronics manufacturing and packaging methods. The hybrid in-mould integration technology concept is based on combination of roll-to-roll (R2R) printed electronics, discrete component assembly, film forming and injection overmoulding/in-mould labelling (IML) processes. In this study, compatibility and feasibility of the technology for low-cost disposable healthcare sensor applications, especially pulse oximeters, was investigated. Flexible printed circuit (FPC) substrates for pulse oximeter applications were manufactured in high-volume and low cost fashion by R2R printing and etching processes. Surface mount technology (SMT) and leadframe components were assembled on FPCs by using adhesive bonding technology. The assembly process was also demonstrated using automated, high-volume capable machine. It was proven that SMD components and their interconnections on flex withstand the injection overmoulding process and can thus be embedded seamlessly inside plastic parts. By the use of the same injection moulding process it was also demonstrated that rigid mechanical locking features manufactured by film overmoulding can be combined with the flexibility of FPC. In order to speed up the iteration cycles of the hybrid integration design flow, a new method was developed for rapid prototyping of in-mould integrated products. In the method, 3D printing was used to create a master for a silicone mould, and assembled FPC was overmolded in vacuum casting process with polyurethane material. This paper presents also other research activities at VTT Technical Research Centre of Finland in the field of hybrid system integration carried out in various collaborative projects with companies and research institutes in Europe. The demonstrators realised in these projects include autonomous, intelligent lighting and signaling systems for automotive and traffic signs, in-molded optical touch panel and flexible printed organic light-emitting diode (OLED) embedded into 3D plastic structure using IML-like process in which active OLED foils are used instead of graphic foils. The demonstrators prove that hybrid in-mould integration could be a feasible technology enabling seamless integration of optical, electrical and mechanical features into 3D plastic products.


2004 ◽  
Vol 1-2 ◽  
pp. 179-184 ◽  
Author(s):  
T. Yan ◽  
B.E. Jones ◽  
R.T. Rakowski ◽  
M.J. Tudor ◽  
S.P. Beeby ◽  
...  

A joint Brunel-Southampton Universities’ research team has developed digital strain gauges based on a metallic triple-beam resonator structure with thick-film piezoelectric sensor elements. The resonator, an oscillating structure vibrating at resonance, is designed such that its resonant frequency is a function of the measurand. The resonator substrate was fabricated by a double-sided photochemical etching technique and the thick-film piezoelectric elements were deposited by a standard screen-printing process. The new metallic digital strain gauges can be used on stiff structures, have high overload capacities, low power consumption, frequency output for digital processing, and offer prospects for wireless-batteryless operation. The device can be easily mass-produced at low cost for use in a wide range of measuring systems, e.g. load cells, weighing machines, torque transducers and pressure sensors.


2018 ◽  
Vol 192 ◽  
pp. 01039 ◽  
Author(s):  
Pattanaphong Janphuang ◽  
Mongkhol Laebua ◽  
Chanwut Sriphung ◽  
Phatsakon Taweewat ◽  
Anan Sirichalarmkul ◽  
...  

This paper presents the development of a polymer based microneedle patch for transdermal drug delivery application using plastic microinjection moulding. Design and analysis of the microneedle cavities and mould insert used in the injection moulding process were carried out using Computer-Aided Engineering (CAE) software. A mould insert with low surface roughness was fabricated using Micro Electrical Discharge Machining (μ-EDM). The injection moulding parameters including clamping force, temperature, injection pressure and velocity were characterized in order to obtain the optimum reproducibility. Solid truncated cone microneedles, made of biocompatible polymethyl methacrylate (PMMA), with a round tip radius of 50 μm and 500 μm in height have been realized by microinjection moulding process demonstrating the potential of a low cost, high production efficiency, and suitable for mass production. In addition, a mould insert of cylindrical microneedles fabricated using X-ray LIGA has been proposed.


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