Preliminary Study on the Manufacturing Feasibility of Microfeatures for Microfluidics by DLP Stereolithography

2019 ◽  
Author(s):  
Lara Rebaioli ◽  
Irene Fassi
Keyword(s):  
Process Parameters ◽  
Cross Sections ◽  
Dimensional Accuracy ◽  
Single Step ◽  
Main Process ◽  
Single Chip ◽  
Feature Size ◽  
Digital Light Processing ◽  
3D Shapes ◽  
Am Processes

Abstract Lab on Chips (LOCs) are devices mostly based on microfluidics (i.e. structures for liquid handling with cross sections of 1–500 μm and femtoliter to nanoliter volume capacity), which allow to perform one or several chemical, biochemical or biological analysis in a miniaturized format on a single chip. The emerging Additive Manufacturing (AM) processes could produce a complete LOC with microscale complex 3D shapes in a single step without the need for assembly processes. Stereolithography, especially when exploiting the Digital Light Processing (DLP) technology, is the most promising AM process for this purpose. In this study, a suitable benchmark part was designed to assess the feasibility of manufacturing microfeatures by DLP-SLA and to evaluate the performance of the employed system in terms of the minimum feature size, dimensional accuracy and spatial repeatability. A proper experimental campaign was specifically studied to point out the effect of the main process parameters (namely, layer thickness and exposure time) and the feature position within the building platform on the process performance. The results demonstrated the manufacturing feasibility of the selected microfeatures. Moreover, they showed that both the process parameters influence the minimum feasibile feature size and that the dimensional accuracy changes with the feature position.

Experimental Investigation of Microfluidic Feature Manufacturing by Digital Light Processing Stereolithography

2020 ◽  
Author(s):  
Lara Rebaioli ◽  
Irene Fassi
Keyword(s):  
Process Parameters ◽  
Low Cost ◽  
Dimensional Accuracy ◽  
Machine Building ◽  
Single Step ◽  
Main Process ◽  
Single Chip ◽  
Digital Light Processing ◽  
And Performance ◽  
User Friendly

Abstract Lab on Chips (LOCs) are devices, mostly based on microfluidics, that allow to perform one or several chemical, biochemical or biological analysis in a miniaturized format on a single chip. The Additive Manufacturing processes, and in particular the Digital Light Processing stereolithography (DLP-SLA), could quickly produce a complete LOC with high resolution 3D features in a single step, i.e. without the need for assembly processes, and using low cost and user-friendly desktop machines. However, the potential of DLP-SLA to produce non-planar channels or channels with complex sections has not been fully investigated yet. This study proposes a benchmark artifact (including also some channels with their axis lying in a plane parallel to the machine building platform) aiming at assessing the capability and performance of DLP-SLA for manufacturing microfeatures for microfluidic devices. A proper experimental campaign was performed to evaluate the effect of the main process parameters (namely, layer thickness and exposure time) on the process performance. The results pointed out that both the process parameters influence the quality and dimensional accuracy of the analyzed features.

A Benchmark Artifact to Evaluate the Manufacturing of Microfeatures by Digital Light Processing Stereolithography

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Lara Rebaioli ◽  
Irene Fassi
Keyword(s):  
Layer Thickness ◽  
Exposure Time ◽  
Process Parameters ◽  
Dimensional Accuracy ◽  
Main Process ◽  
Process Performance ◽  
Digital Light Processing ◽  
Specific Process ◽  
Experimental Campaign ◽  
Increasing Demand

Abstract Suitable benchmark artifacts are needed for assessing the technological capabilities and limitations of a specific process or for comparing the performances of different processes. Only a few benchmark artifacts have been specifically designed for features with microscale dimensions, even if their manufacturing is becoming very common due to the increasing demand for miniaturized parts or objects with microscale features. In this study, a suitable benchmark part is designed to evaluate the geometrical performance of a digital light processing (DLP) stereolithography (SLA) system for manufacturing microfeatures. The effect of the main process parameters (i.e., layer thickness and exposure time) and the feature position within the building platform on the process performance was assessed by a specifically studied experimental campaign. The results show that both the analyzed process parameters influence the minimum feasible size of protruding features and that the feature position influences the dimensional accuracy.

Large-Diameter Line Pipe Expanding Process

2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li
Keyword(s):  
Process Parameters ◽  
Large Diameter ◽  
Dimensional Accuracy ◽  
Optimization Method ◽  
Main Process ◽  
Shape Accuracy ◽  
Line Pipe ◽  
Factors Affecting ◽  
Array Optimization

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.

On Technologies of Electrochemical Finishing with Pulsed Current

2012 ◽  
Vol 522 ◽  
pp. 41-46
Author(s):  
Adayi Xieeryazidan ◽  
Muhetar Wumerhali ◽  
Gui Bing Pang
Keyword(s):  
Surface Quality ◽  
Process Parameters ◽  
Dimensional Accuracy ◽  
Experimental Results ◽  
Main Process ◽  
Pulsed Current ◽  
Electrode Gap ◽  
Electric Parameter ◽  
Machining Quality ◽  
Electrochemical Finishing

Electrochemical finishing with pulsed current (ECFP) is introduced in this paper. The main process parameters, such as electric parameter and inter-electrode gap, etc., were investigated. The results show that the ECFP is an effective finishing method for improving the machining quality as the result of the machining mechanism. The related experimental results show that the obtained surface quality and dimensional accuracy are improved significantly as the result of the application of the pulsed current. Moreover, machining quality is increased with shorter pulses.

scholarly journals 3D printing with moondust

2016 ◽  
Vol 22 (6) ◽  
pp. 864-870 ◽  
Author(s):  
Athanasios Goulas ◽  
Ross J. Friel
Keyword(s):  
Process Parameters ◽  
Lunar Regolith ◽  
Dimensional Accuracy ◽  
Main Process ◽  
Material Particle ◽  
Content Type ◽  
Material Hardness ◽  
Lunar Regolith Simulant ◽  
Potential Applicability ◽  
Relative Porosity

Purpose The purpose of this paper is to investigate the effect of the main process parameters of laser melting (LM) type additive manufacturing (AM) on multi-layered structures manufactured from JSC-1A Lunar regolith (Moondust) simulant powder. Design/methodology/approach Laser diffraction technology was used to analyse and confirm the simulant powder material particle sizes and distribution. Geometrical shapes were then manufactured on a Realizer SLM™ 100 using the simulant powder. The laser-processed samples were analysed via scanning electron microscopy to evaluate surface and internal morphologies, X-ray fluorescence spectroscopy to analyse the chemical composition after processing, and the samples were mechanically investigated via Vickers micro-hardness testing. Findings A combination of process parameters resulting in an energy density value of 1.011 J/mm2 allowed the successful production of components directly from Lunar regolith simulant. An internal relative porosity of 40.8 per cent, material hardness of 670 ± 11 HV and a dimensional accuracy of 99.8 per cent were observed in the fabricated samples. Originality/value This research paper is investigating the novel application of a powder bed fusion AM process category as a potential on-site manufacturing approach for manufacturing structures/components out of Lunar regolith (Moondust). It was shown that this AM process category has the capability to directly manufacture multi-layered parts out of Lunar regolith, which has potential applicability to future moon colonization.

Rheological and printable behavior of resin – class materials for 3D printing applications

2019 ◽  
Vol 25 (5) ◽  
pp. 801-808
Author(s):  
Jianzhong Shang ◽  
Xin Li ◽  
Zhuo Wang ◽  
Rong Wang ◽  
Hong Zhu
Keyword(s):  
Process Parameters ◽  
Cross Sections ◽  
Rheological Behavior ◽  
Dimensional Accuracy ◽  
Cross Sectional ◽  
Content Type ◽  
Nozzle Height ◽  
Uniform Wall ◽  
The Cross ◽  
Printing Parameters

Purpose This study aims to investigate rheological and extrusion behavior of thermosetting epoxy resins, which to find the universal property and printing parameters for extrusion-based rapid prototyping applications. Design/methodology/approach The thickener proportion greatly influences its viscosity and rheological behavior and therefore plays an important role in the shape of the cross-section of the extrudate. Findings A pseudoplastic (shear-thinning) is a basic requirement for obtaining extruded lines with plump cross-sections. In addition to the effects of the rheological behavior of the composite, shape maintenance and its wettability on the substrate, the cross-sectional geometry of the extrudate is also strongly affected by printing process parameters including the extrusion nozzle height, nozzle moving speed, extrusion rate and critical nozzle height. Proper combinations of these process parameters are necessary to obtain single-line extrudates with plump cross-sections and 3-D objects with dimensional accuracy, uniform wall thickness, good wall uprightness and no wall slumping. Formulas and procedures for determining these extrusion parameters are proposed and demonstrated in experiments. Originality/value The results obtained have been explained in terms of the interactions among the rheological properties of the composite, the shear rate imposed on the composite during extrusion, the wettability of the composite on the substrate and the shape maintenance of the composite during extrusion.

scholarly journals Shoulder Related Temperature Thresholds in FSSW of Aluminium Alloys

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues
Keyword(s):  
Heat Generation ◽  
Process Parameters ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Spot Welding ◽  
Base Material ◽  
Main Process ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Diameter

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.

scholarly journals Dimensional Accuracy of Dental Models for Three-Unit Prostheses Fabricated by Various 3D Printing Technologies

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1550
Author(s):  
Soo-Yeon Yoo ◽  
Seong-Kyun Kim ◽  
Seong-Joo Heo ◽  
Jai-Young Koak ◽  
Joung-Gyu Kim
Keyword(s):  
Surface Roughness ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
3D Analysis ◽  
Digital Light Processing ◽  
Test Models ◽  
Reference File ◽  
Significant Difference ◽  
Jet Printing ◽  
3D Printed

Previous studies on accuracy of three-dimensional (3D) printed model focused on full arch measurements at few points. The aim of this study was to examine the dimensional accuracy of 3D-printed models which were teeth-prepped for three-unit fixed prostheses, especially at margin and proximal contact areas. The prepped dental model was scanned with a desktop scanner. Using this reference file, test models were fabricated by digital light processing (DLP), Multi-Jet printing (MJP), and stereo-lithography apparatus (SLA) techniques. We calculated the accuracy (trueness and precision) of 3D-printed models on 3D planes, and deviations of each measured points at buccolingual and mesiodistal planes. We also analyzed the surface roughness of resin printed models. For overall 3D analysis, MJP showed significantly higher accuracy (trueness) than DLP and SLA techniques; however, there was not any statistically significant difference on precision. For deviations on margins of molar tooth and distance to proximal contact, MJP showed significantly accurate results; however, for a premolar tooth, there was no significant difference between the groups. 3D color maps of printed models showed contraction buccolingually, and surface roughness of the models fabricated by MJP technique was observed as the lowest. The accuracy of the 3D-printed resin models by DLP, MJP, and SLA techniques showed a clinically acceptable range to use as a working model for manufacturing dental prostheses

scholarly journals Demonstration of a Polymer-Based Single Step Waveguide by 3D Printing Digital Light Processing Technology for Isopropanol Alcohol-Concentration Sensor

2021 ◽  
Author(s):  
Kankan Swargiary ◽  
Romuald Jolivot ◽  
Waleed Soliman Mohammed
Keyword(s):  
Refractive Index ◽  
3D Printing ◽  
Limit Of Detection ◽  
Optical Power ◽  
Alcohol Concentration ◽  
Single Step ◽  
Gap Size ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
The Core

AbstractA polymer based horizontal single step waveguide for the sensing of alcohol is developed and analyzed. The waveguide is fabricated by 3-dimensional (3D) printing digital light processing (DLP) technology using monocure 3D rapid ultraviolet (UV) clear resin with a refractive index of n = 1.50. The fabricated waveguide is a one-piece tower shaped ridge structure. It is designed to achieve the maximum light confinement at the core by reducing the effective refractive index around the cladding region. With the surface roughness generated from the 3D printing DLP technology, various waveguides with different gap sizes are printed. Comparison is done for the different gap waveguides to achieve the minimum feature gap size utilizing the light re-coupling principle and polymer swelling effect. This effect occurs due to the polymer-alcohol interaction that results in the diffusion of alcohol molecules inside the core of the waveguide, thus changing the waveguide from the leaky type (without alcohol) to the guided type (with alcohol). Using this principle, the analysis of alcohol concentration performing as a larger increase in the transmitted light intensity can be measured. In this work, the sensitivity of the system is also compared and analyzed for different waveguide gap sizes with different concentrations of isopropanol alcohol (IPA). A waveguide gap size of 300 µm gives the highest increase in the transmitted optical power of 65% when tested with 10 µL (500 ppm) concentration of IPA. Compared with all other gaps, it also displays faster response time (t = 5 seconds) for the optical power to change right after depositing IPA in the chamber. The measured limit of detection (LOD) achieved for 300 µm is 0.366 µL. In addition, the fabricated waveguide gap of 300 µm successfully demonstrates the sensing limit of IPA concentration below 400 ppm which is considered as an exposure limit by “National Institute for Occupational Safety and Health”. All the mechanical mount and the alignments are done by 3D printing fused deposition method (FDM).

scholarly journals Analysis of the Downscaling Effect and Definition of the Process Fingerprints in Micro Injection of Spiral Geometries

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 335 ◽  
Author(s):  
Antonio Luca ◽  
Oltmann Riemer
Keyword(s):  
Correlation Analysis ◽  
Process Parameters ◽  
Cross Sections ◽  
Mass Production ◽  
Process Window ◽  
Response Variable ◽  
Process Indicators ◽  
Flow Length ◽  
Definition Of ◽  
Microinjection Moulding

Microinjection moulding has been developed to fulfil the needs of mass production of micro components in different fields. A challenge of this technology lies in the downscaling of micro components, which leads to faster solidification of the polymeric material and a narrower process window. Moreover, the small cavity dimensions represent a limit for process monitoring due to the inability to install in-cavity sensors. Therefore, new solutions must be found. In this study, the downscaling effect was investigated by means of three spiral geometries with different cross sections, considering the achievable flow length as a response variable. Process indicators, called “process fingerprints”, were defined to monitor the process in-line. In the first stage, a relationship between the achievable flow length and the process parameters, as well as between the process fingerprints and the process parameters, was established. Subsequently, a correlation analysis was carried out to find the process indicators that are mostly related to the achievable flow length.

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