In injection moulding, continuous monitoring of temperature and pressure parameters in the mould cavity is very important for process control and optimization. In the micro injection moulding process, however, it is more difficult to measure the cavity pressure and temperature due to the extremely small sizes involved. In this paper, a novel setup for cavity pressure and temperature measurements is presented: a miniaturized p,T quartz sensor is used to measure both pressure and temperature directly in the middle of the mould cavity and a data acquisition system has been developed in order to collect signals provided by the sensors. It was demonstrated the suitability of the novel setup to micro injection moulding and that it can be easily applied to any micro injection moulding machine.

This paper reports on design, fabrication, and characterization of a microfilter to be used in biomedical applications. The microfilter, with mesh of 80 ?m, is fabricated by micro-injection molding process in polymeric material (polyoxymethylene (POM)) using a steel mold manufactured by micro-electrical discharge machining process. The characteristics of the filter are investigated by numerical simulation in order to define a suitable geometry for micro-injection molding. Then, different process configurations of parameters (melt temperature, injection velocity, mold temperature, holding pressure and time, cooling time, pressure limit) are tested in order to obtain the complete part filling via micro-injection molding process preventing any defects. Finally, the component is dimensionally characterized and the process parameters optimized to obtain the maximum filtration capacity.

The present paper reports the design and fabrication of a mould for mass production of a microfluidic device, "opticalstretcher lab-on-chip, a dual-beam optical trap that is used for trapping and deforming micrometer-sized particles.In particular, the mould is designed considering multiple and interchangeable inserts for realizing different microfeaturesadopting different processes. Microchannel, reservoirs and V-grooves have been machined viafemtosecond laser process due its capability to process large surface areas with relatively small depth features andhigh removal rate. On the contrary, complex 3D micro features with high aspect ratio for inverse capillary tubehousing have been manufactured via ?-electro-discharge-machining technology, since fine pulse discharges canbe used to ensure high precision and good surface roughness. Three-dimensional filling numerical analysis hasbeen also performed to improve the device design for the ?-injection moulding process and to set the optimizedprocess parameters. Several prototypes of the Lab-on-chip have been fabricated and experimental tests have beenperformed, showing the feasibility of this technological approach

This paper reports on design, fabrication and characterization of a micro-filter for hearing aid, dialysis media and inhaler. The microfilter is fabricated by micro injection moulding process in polymeric material (Polyoxymethilene - POM) using a steel mould manufactured by micro electrical discharge machining process. A novel filter configuration is proposed and, in the design step, the characteristics of the filter are investigated by numerical simulation in order to define a suitable geometry for micro-injection moulding. Then, different process configuration of parameters (melt and mould temperature, injection velocity, holding time and pressure, cooling time, pressure limit) are tested in order to obtain the complete part filling. Finally the component is dimensionally characterized and the process parameters optimized to obtain the maximum filtration capacity.

Due to the sensitive nature of applications of the micro injection moulding process, such as medical and aerospace, achieving high quality parts with high dimensional accuracy is crucial. In this work, simulation and an experimental study was performed to analyse the effect of four main parameters (melt and mould temperature, injection speed and holding pressure) on dimensional accuracy of a micro feature. Moreover, the focus was also to assess the process capability of a screwless/two plungers micro moulding machine in processing polyoximethilene (POM) and liquid crystal polymers (LCP). Results showed that mould temperature and injection speed was the most effective on dimensional accuracy respectively for POM and LCP and high settings for all the parameters improved the accuracy of the ribs. For LCP achieving process reproducibility was more difficult than POM even if the obtained dimensional errors are considerably lower.

Microinjection moulding combined with the use of removable inserts is one of the most promising manufacturing processes for microfluidic devices, such as lab-on-chip, that have the potential to revolutionize the healthcare and diagnosis systems. In this work, we have designed, fabricated and tested a compact and disposable plastic optical stretcher. To produce the mould inserts, two micro manufacturing technologies have been used. Micro electro discharge machining (µEDM) was used to reproduce the inverse of the capillary tube connection characterized by elevated aspect ratio. The high accuracy of femtosecond laser micromachining (FLM) was exploited to manufacture the insert with perfectly aligned microfluidic channels and fibre slots, facilitating the final composition of the optical manipulation device. The optical stretcher operation was tested using microbeads and red blood cells solutions. The prototype presented in this work demonstrates the feasibility of this approach, which should guarantee real mass production of ready-to-use lab-on-chip devices.

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.

Microfluidic optical stretchers are valuable optofluidic devices for studying single cell mechanical properties. These usually consist of a single microfluidic channel where cells, with dimensions ranging from 5 to 20 ?m are trapped and manipulated through optical forces induced by two counter-propagating laser beams. Recently, monolithic optical stretchers have been directly fabricated in fused silica by femtosecond laser micromachining (FLM). Such a technology allows writing in a single step in the substrate volume both the microfluidic channel and the optical waveguides with a high degree of precision and flexibility. However, this method is very slow and cannot be applied to cheaper materials like polymers. Therefore, novel technological platforms are needed to boost the production of such devices on a mass scale. In this work, we propose integration of FLM with micro-injection moulding (?IM) as a novel route towards the cost-effective and flexible manufacturing of polymeric Lab-on-a-Chip (LOC) devices. In particular, we have fabricated and assembled a polymethylmethacrylate (PMMA) microfluidic optical stretcher by exploiting firstly FLM to manufacture a metallic mould prototype with reconfigurable inserts. Afterwards, such mould was employed for the production, through ?IM, of the two PMMA thin plates composing the device. The microchannel with reservoirs and lodgings for the optical fibers delivering the laser radiation for cell trapping were reproduced on one plate, while the other included access holes to the channel. The device was assembled by direct fs-laser welding, ensuring sealing of the channel and avoiding thermal deformation and/or contamination.

Since traditional handling mechanisms have an unpredictable behavior at micro scale, micro-assembly is a bottleneck in the development of hybrid micro-systems, and the development of new approaches is strongly demanded. In this paper, a recent study of the fabrication of a ceramics vacuum micro-gripper to handle parts in the range of hundreds of microns (300-1000) is presented. Among the possible micro manufacturing processes, micro-EDM has been selected as proving to be a very competitive fabrication technology for the manufacturing of ultra miniature components and micro sized features. The influence of the process parameters on the machining performance of interest is firstly investigated; then, the experimental results on machining the micro gripper are presented, finally concluding remarks are given.

In this work we present a micro manufacturing platform for the production of polymeric microfluidic devices on a mass scale, based on the integration of microinjection moulding and femtosecond laser (fs-laser) micromachining technologies. A mould prototype was designed for the fabrication of polymeric thin plates characterized by simplified microfeatures representative of typical Lab-on-a-Chip (LoC) devices. The injection moulding master tool includes replaceable metallic inserts, which were fabricated by exploiting the extreme flexibility and accuracy of fs-laser milling. Here, the laser process parameters have been studied and properly adjusted to meet the target geometry and surface quality of the mould inserts, which were subsequently characterized by confocal and SEM microscopy. The micro injection moulding (?IM) process parameters for the device production have been defined by complete three-dimensional filling and packing process simulations. Finally, the micro-injection mould with reconfigurable inserts was employed for the production of thin plates with simplified microfeatures using PMMA. The ability to reproduce these microfeatures via ?IM is an essential step to approach to the mass-production of a polymeric LoC and the use of replaceable micro-inserts fabricated by direct fs-laser ablation promises high flexibility in the design and manufacturing of such devices.

We present a cost-effective and highly-portable plastic prototype that can be interfaced with a cell phone to implement an optofluidic imaging cytometry platform. It is based on a PMMA microfluidic chip that fits inside an opto-mechanical platform fabricated by a 3D printer. The fluorescence excitation and imaging is performed using the LED and the CMOS from the cell phone increasing the compactness of the system. A custom developed application is used to analyze the images and provide a value of particle concentration.

The concept of replaceable micro cavities can be applied in the design of moulds for different applications and the efficiency of the product development stage is greatly improved. The inserts allow easy testing of the design prototypes especially in highly interdisciplinary fields where manufacturing challenges such as replication, structuring of moulds, polymers, sealing, integration of functional elements, and the production of (customised) disposables at competitive prices all still need to be addressed. In this direction laser micromachining technology meets the need for fabricating micro-injection mould inserts with complex shapes and a high level of accuracy.

Micro injection moulding process represents a key technology for realizing micro components and micro devices used in several fields: IT components, biomedical and medical products, automotive industry, telecommunication area and aerospace. The development of new micro parts is highly dependent on manufacturing systems that can reliably and economically produce micro components in large quantities. In this work the authors investigate the process parameters on the overall quality of a miniaturized dog-bone shaped specimen. The factors affecting micro flow behavior and components mass were studied byexperimentation (designed using DoE methodology) and simulation tool and then discussed. Different polymer materials, particularly indicated for the injection molding applications due to their flowability and stability, are tested and evaluated in relation to the process replication capability.It has been found that the holding pressure and holding time for Polyoxymethylene (POM) and holding pressure and injection velocity for Liquid Cristal Polymer (LCP) have the higher influence on achieving high part mass.

Micro Electrical Discharge Machining (liEDM) technology is widely used to process conductive materials, regardless to their hardness and strength, and realize micro-sized feature components for industrial application. liEDM proves to be a very competitive fabrication technology since micro-sized features within 1 Lim of accuracy and with high surface quality (<0.1 Lim Ra) can be attained. When High Aspect Ratio (HAR) micro-features are machined via liEDM milling, the main problem is to identify the technological parameters and settings mainly affecting the process performance. In the present study the influence of the adjustment factor and flushing conditions are investigated and discussed for the machining of HAR cavities with different Fill Factor (FF). Material Removal Rate (MRR) and Tool Wear Ratio (TWR) are evaluated when deep cavities having variable square sections are machined on Ni-Cr-Mo steel workpiece. All tests are performed using a state of the art micro-EDM milling machine, with a Tungsten Carbide electrode tool and a dielectric oil for flushing. The experimental results presented here highlight different trends in the machining performance in dependence of AR and FF. In particular, MRR exhibits a decreasing trend where the curve slopes are strictly related to the FF and the initial adjustment factor. On the contrary,TWR, for higher FF, displays two distinct trends characterized by opposite slopes in each curve. Finally a nozzle for micro-injection with varying Aspect Ratio and Fill Factor is machined and presented as demonstrator.

Micro components and micro devices are strongly used in several fields: IT components, biomedical and medical products, automotive industry, telecommunication area and aerospace. A micro component is characterized by small dimensions of the product itself or small dimensions of the functional features. The development of new micro parts is highly dependent on manufacturing systems that can reliably and economically produce micro components in large quantities. In this context, micro-electrical discharge machining (EDM) for mould production and micro-injection moulding of polymer materials are the key technologies for micro manufacturing. This paper will focus on the production and quality evaluation of polymeric micro components manufactured by micro injection moulding. In particular the authors want to investigate the process parameters on the overall quality of the product. The factors affecting micro flow behavior, components weights and dimension definition are experimentally studied basing on DoE approach and then discussed.

Due to its high efficiency for the large scale production of polymeric parts, micro injection moulding is one of the key technologies of the new millennium. Although a lot of researches have been conducted to identify the most effective processing conditions for micro injection moulding, the comprehension of the influence of all parameters on the quality, the properties and the reliability of the moulded parts is still an issue. In this context, this study aims to evaluate the effects of the micro injection moulding process conditions on the tensile properties of micro parts, investigating the influence of three main process parameters: the injection speed, the mould temperature and the melt temperature. A full factorial plan has been applied to study the contributions of these parameters and a second study has been performed to understand the synergic interaction between the two temperatures on the tensile strength. Due to its high level of potential crystallinity, a typical semi-crystalline thermoplastic resin was used in the experiments. The results of the analysis showed a great influence of the mould temperature (T mould) on the ultimate tensile strength and of the melt temperature (T melt) on the deformation at the point of breaking; whereas the injection speed was significant on the overall mechanical performance. A new studied factor (T melt-T mould) could affect the resulting molecular structure and consequently the mechanical behaviour, but itself is not sufficient to thoroughly explain the observed behaviour. Moreover, the visual inspection of the deformation mechanism at break shows three distinctive trends demonstrating the great variability of the mechanical properties of micro-injected specimens due to process conditions.

We have introduced a new hybrid fabrication method for lab-on-a-chip devices through the combination of femtosecond laser micromachining and removable insert micro-injection molding. This method is particularly suited for the fast prototyping of new devices, while maintaining a competitive low cost. To demonstrate the effectiveness of our approach, we designed, fabricated, and tested a completely integrated flow cytometer coupled to a portable media device. The system operation was tested with fluorescent plastic micro-bead solutions ranging from 100 beads/?L to 500 beads/?L. We demonstrated that this hybrid lab-on-a-chip fabrication technology is suitable for producing low-cost and portable biological microsystems and for effectively bridging the gap between new device concepts and their mass production.

Achieving high quality parts is a crucial task for the micro injection moulding process due to the sensitive nature of applications as medical and aerospace. In this work, simulation and an experimental study are performed to analyse the effect of four main parameters (injection speed, melt and mould temperature, and holding pressure) on replicating capability of a micro feature by injection moulding process that is the main focus of the present paper. This work also assesses the performance of a screwless-two plungers micro moulding machine in processing polyoximethilene (POM) and liquid crystal polymers (LCP). Results show that mould temperature and injection speed are the most effective parameters on replicating capability respectively for {POM} and {LCP} and high parameters setting improved the dimensions of the feature and thus the quality. For LCP, achieving process reproducibility is more difficult than for {POM} even if the obtained replication fidelity is considerably higher.

Micro injection moulding process represents a key technology for realizing micro components and micro devices used in several fields: IT components, biomedical and medical products, automotive industry, telecommunication area and aerospace. The development of new micro parts is highly dependent on manufacturing systems that can reliably and economically produce micro components in large quantities. In this work, the authors investigate the process parameters on the overall quality of a miniaturised dog-bone-shaped specimen in order to determine the process constraints. The factors affecting parts aspects and mass are studied by experimentation designed using DoE methodology and then discussed. Two polymer materials (polyoxymethylene and liquid crystal polymer), particularly suitable for injection moulding applications due to their flowability and stability, are tested and evaluated in relation to the process replication capability. It has been found that the holding pressure and holding time for POM and holding pressure and injection velocity for LCP have the highest influence on achieving high part mass. Differently, melt temperature has the highest influence on minimising the process variability for both tested polymers. A further investigation has been carried out on the relationship between the holding pressure and the part mass and dimensions demonstrating the existence of a linear correlation between specimens mass and dimensions.

Le leghe di magnesio sono state utilizzate sino a qualche anno fa soprattutto nel settore dell'aviazione militare e delle apparecchiature elettroniche, grazie ad alcune particolari proprietà tra cui una minore densità rispetto alle altre leghe metalliche e un ottimo rapporto resistenza-peso. L'impiego delle leghe di magnesio ha comunque acquistato notevole interesse anche in applicazioni di altri settori come per esempio quello automobilistico, per la produzione di involucri e altri dispositivi con il miglior compromesso tra leggerezza e resistenza meccanica del componente. In genere le applicazioni sono rivolte alla produzione di getti presso fusi, per la predisposizione della lega a questo processo di fabbricazione. Con l'obiettivo di estendere le applicazioni anche a componenti realizzati mediante lavorazioni di lamiere, sono state avviate Taglio laser di lamiere in lega di magnesio AZ31.