scholarly journals ADDITIVE MANUFACTURING OF HOLLOW MICRONEEDLES FOR INSULIN DELIVERY

2021 ◽  
Vol 13 (3) ◽  
pp. 185-190
Author(s):  
Iakovos Xenikakis ◽  
◽  
Konstantinos Tsongas ◽  
Emmanouil K Tzimtzimis ◽  
Dimitrios Tzetzis ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Liquid Crystal Display ◽  
Insulin Delivery ◽  
Average Height ◽  
Curing Time ◽  
Constant Height ◽  
3D Printed ◽  
Printing Parameters ◽  
Hollow Microneedles

Microneedles (MN) are miniature devices capable of perforating painlessly stratum corneum and delivering active ingredients in the inner epidermal layers. Hollow microneedles (HMNs) are highly detailed objects due to their internal microchannels and thus, their fabrication with Additive Manufacturing (AM) is a challenging task. Vat polymerization techniques provide a sufficient accuracy for such microstructures. Differentiated from other approaches where stereolithography and 2-photon polymerization were adopted, this paper presents the 3D-printing of HMNs purposed for insulin delivery, using the more economic Liquid Crystal Display (LCD) method. First, different geometries (hexagon, square pyramid, beveled) were 3D printed with constant height and varying curing time, printing angle and layer resolution. Quality features in each case were captured with optical and scanning electron microscopy (SEM). The most promising geometry was found to be the beveled one due to the more refined tip area and the feasibility of non-clogged microchannel formation. Among printing parameters, printing angle proved to be the most influential, as it affects resin flow phenomenon during printing process. Lastly, optimized HMN geometry was the beveled configuration, where the average height was measured 900μm, 3D printing angle was set at -45°, the curing time was 10s per layer and the optimal layer height was 30μm.

scholarly journals Evaluation of the Ability to Accurately Produce Angular Details by 3D Printing of Plastic Parts

Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 150
Author(s):  
Andrei Marius Mihalache ◽  
Gheorghe Nagîț ◽  
Laurențiu Slătineanu ◽  
Adelina Hrițuc ◽  
Angelos Markopoulos ◽  
...  
Keyword(s):  
3D Printing ◽  
Point Of View ◽  
Vertex Angle ◽  
Function Type ◽  
Constant Height ◽  
3D Printers ◽  
3D Printed ◽  
Mathematical Processing ◽  
Plastic Parts

3D printing is a process that has become widely used in recent years, allowing the production of parts with relatively complicated shapes from metallic and non-metallic materials. In some cases, it is challenging to evaluate the ability of 3D printers to make fine details of parts. For such an assessment, the printing of samples showing intersections of surfaces with low angle values was considered. An experimental plan was designed and materialized to highlight the influence of different factors, such as the thickness of the deposited material layer, the printing speed, the cooling and filling conditions of the 3D-printed part, and the thickness of the sample. Samples using areas in the form of isosceles triangles with constant height or bases with the same length, respectively, were used. The mathematical processing of the experimental results allowed the determination of empirical mathematical models of the power-function type. It allowed the detection of both the direction of actions and the intensity of the influence exerted by the input factors. It is concluded that the strongest influence on the printer’s ability to produce fine detail, from the point of view addressed in the paper, is exerted by the vertex angle, whose reduction leads to a decrease in printing accuracy.

Fused Filament Fabrication 3D Printed Polylactic Acid Electroosmotic Pumps

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Liang Wu ◽  
Stephen Beirne ◽  
Joan-Marc Cabot Canyelles ◽  
Brett Paull ◽  
Gordon G. Wallace ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Polylactic Acid ◽  
Fused Filament Fabrication ◽  
Flexible Approach ◽  
Electroosmotic Pump ◽  
3D Printed ◽  
Electroosmotic Pumps

Additive manufacturing (3D printing) offers a flexible approach for the production of bespoke microfluidic structures such as the electroosmotic pump. Here a readily accessible fused filament fabrication (FFF) 3D printing...

APPLICATION OF 3D PRINTING TECHNOLOGY FOR RAPID TOOLING IN SHEET METAL FORMING

2020 ◽  
Vol 3 ◽  
pp. 20-30
Author(s):  
M.A. SEREZHKIN ◽  
D.O. KLIMYUK ◽  
A.I. PLOKHIKH
Keyword(s):  
3D Printing ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Rapid Tooling ◽  
Printing Technology ◽  
3D Printing Technology ◽  
3D Printed ◽  
Printed Materials ◽  
Printing Parameters

The article presents the study of the application of 3D printing technology for rapid tooling in sheet metal forming for custom or small–lot manufacturing. The main issue of the usage of 3D printing technology for die tooling was discovered. It is proposed to use the method of mathematical modelling to investigate how the printing parameters affect the compressive strength of FDM 3D–printed parts. Using expert research methods, the printing parameters most strongly affecting the strength of products were identified for further experiments. A method for testing the strength of 3D–printed materials has been developed and tested.

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

scholarly journals Strength Comparison of FDM 3D Printed PLA Made by Different Manufacturers

TEM Journal ◽  
2020 ◽  
pp. 966-970
Author(s):  
Damir Hodžić ◽  
Adi Pandžić ◽  
Ismar Hajro ◽  
Petar Tasić
Keyword(s):  
Experimental Study ◽  
Additive Manufacturing ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Manufacturing Technique ◽  
Plastic Materials ◽  
Wide Range ◽  
3D Printed ◽  
The Difference ◽  
Printing Parameters

Widely used additive manufacturing technique for plastic materials is Fused Deposition Modelling (FDM). The FDM technology has gained interest in industry for a wide range of applications, especially today when large number of different materials on the market are available. There are many different manufacturers for the same FDM material where the difference in price goes up to 50%. This experimental study investigates possible difference in strength of the 3D printed PLA material of five different manufacturers. All specimens are 3D printed on Ultimaker S5 printer with the same printing parameters, and they are all the same colour.

Hybrid Polymer Additive Manufacturing of a Darrieus Type Vertical Axis Wind Turbine Design to Improve Power Generation Efficiency

2016 ◽  
Author(s):  
Sourabh Deshpande ◽  
Nithin Rao ◽  
Nitin Pradhan ◽  
John L. Irwin
Keyword(s):  
Power Generation ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Vertical Axis ◽  
Blade Design ◽  
Vertical Axis Wind Turbine ◽  
Wind Turbine Blades ◽  
3D Printed

Utilizing the advantages of additive manufacturing methods, redesigning, building and testing of an existing integral Savonius / Darrieus “Lenz2 Wing” style vertical axis wind turbine is predicted to improve power generation efficiency. The current wind turbine blades and supports made from aluminum plate and sheet are limiting the power generation due to the overall weight. The new design is predicted to increase power generation when compared to the current design due to the lightweight spiral Darrieus shaped hollow blade made possible by 3D printing, along with an internal Savonius blade made from aluminum sheet and traditional manufacturing techniques. The design constraints include 3D printing the turbine blades in a 0.4 × 0.4 × 0.3 m work envelope while using a Stratasys Fortus 400mc and thus the wind turbine blades are split into multiple parts with dovetail joint features, when bonded together result in a 1.2 m tall working prototype. Appropriate allowance in the mating dovetail joints are considered to facilitate the fit and bonding, as well as angle, size and placement of the dovetail to maximize strength. The spiral shape and Darrieus style cross section of the blade that provides the required lift enabling it to rotate from the static condition are oriented laterally for 3D printing to maximize strength. The bonding of the dovetail joints is carried out effectively using an acetone solution dip. The auxiliary components of the wind turbine which include the center support pole, top and bottom support, and center Savonius blades are manufactured using lightweight aluminum. Design features are included in the 3D printed blade parts so that they can be assembled with the aluminum parts in bolted connections. Analysis of the 3D CAD models show that the hybrid aluminum and hollow 3D printed blade construction provides a 50% cost savings over a 3D printed fully solid blade design while minimizing weight and maximizing the strength where necessary. Analysis of the redesign includes a detailed weight comparison, structural strength and the cost of production. Results include linear static finite element analysis for the strength in dovetail joint bonding and the aluminum to 3D printed connections. Additional data reported are the time frame for the design and manufacturing of the system, budget, and an operational analysis of the wind turbine with concern for safety. Results are analyzed to determine the advantages in utilizing a hybrid additive manufacturing and aluminum construction for producing a more efficient vertical axis wind turbine. Techniques used in the production of this type of wind turbine blade are planned to be utilized in similar applications such as a lightweight hovercraft propeller blade design to be tested in future research projects.

History of Additive Manufacturing

2017 ◽  
pp. 1-24 ◽  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Large Scale ◽  
Selective Laser Sintering ◽  
3D Printer ◽  
3D Objects ◽  
History Of ◽  
Pros And Cons ◽  
3D Printed ◽  
The Common

History of additive manufacturing started in the 1980s in Japan. Stereolithography was invented first in 1983. After that tens of other techniques were invented under the common name 3D printing. When stereolithography was invented rapid prototyping did not exists. Tree years later new technique was invented: selective laser sintering (SLS). First commercial SLS was in 1990. At the end of 20t century, first bio-printer was developed. Using bio materials, first kidney was 3D printed. Ten years later, first 3D Printer in the kit was launched to the market. Today we have large scale printers that printed large 3D objects such are cars. 3D printing will be used for printing everything everywhere. List of pros and cons questions rising every day.

scholarly journals Bone-inspired 3D printed structures for construction applications

2019 ◽  
Vol 14 (1) ◽  
pp. 111-124
Author(s):  
Roberto Naboni ◽  
Anja Kunic
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Computational Design ◽  
Bone Microstructure ◽  
Manufacturing Technology ◽  
Support Design ◽  
Efficient Construction ◽  
3D Printed ◽  
Viable Approach ◽  
Tectonic System

Overconsumption of resources is one of the greatest challenges of our century. The amount of material that is being extracted, harvested and consumed in the last decades is increasing tremendously. Building with new manufacturing technology, such as 3D Printing, is offering new perspectives in the way material is utilized sustainably within a construction. This paper describes a study on how to use Additive Manufacturing to support design logics inspired by the bone microstructure, in order to build materially efficient architecture. A process which entangles computational design methods, testing of 3D printed specimens, developments of prototypes is described. A cellular-based tectonic system with the capacity to vary and adapt to different loading conditions is presented as a viable approach to a material-efficient construction with Additive Manufacturing.

scholarly journals DLP 3D Printing Meets Lignocellulosic Biopolymers: Carboxymethyl Cellulose Inks for 3D Biocompatible Hydrogels

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1655 ◽  
Author(s):  
Giuseppe Melilli ◽  
Irene Carmagnola ◽  
Chiara Tonda-Turo ◽  
Fabrizio Pirri ◽  
Gianluca Ciardelli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Carboxymethyl Cellulose ◽  
Biomedical Applications ◽  
Digital Light Processing ◽  
Chemically Modified ◽  
Significant Step ◽  
3D Printed ◽  
Biomedical Field

The development of new bio-based inks is a stringent request for the expansion of additive manufacturing towards the development of 3D-printed biocompatible hydrogels. Herein, methacrylated carboxymethyl cellulose (M-CMC) is investigated as a bio-based photocurable ink for digital light processing (DLP) 3D printing. CMC is chemically modified using methacrylic anhydride. Successful methacrylation is confirmed by 1H NMR and FTIR spectroscopy. Aqueous formulations based on M-CMC/lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator and M-CMC/Dulbecco’s Modified Eagle Medium (DMEM)/LAP show high photoreactivity upon UV irradiation as confirmed by photorheology and FTIR. The same formulations can be easily 3D-printed through a DLP apparatus to produce 3D shaped hydrogels with excellent swelling ability and mechanical properties. Envisaging the application of the hydrogels in the biomedical field, cytotoxicity is also evaluated. The light-induced printing of cellulose-based hydrogels represents a significant step forward in the production of new DLP inks suitable for biomedical applications.

Thermal Conductivity Testing Apparatus for 3D Printed Materials

2017 ◽  
Author(s):  
Tiffaney Flaata ◽  
Gregory J. Michna ◽  
Todd Letcher
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Polymer Composite ◽  
Heat Exchangers ◽  
Fused Deposition ◽  
3D Printed ◽  
Printed Materials ◽  
Metal Polymer

Additive manufacturing, the layer-by-layer creation of parts, was initially used for rapid prototyping of new designs. Recently, due to the decrease in the cost and increase in the resolution and strength of additively manufactured parts, additive manufacturing is increasingly being used for production of parts for end-use applications. Fused Deposition Modeling (FDM), a type of 3d printing, is a process of additive manufacturing in which a molten thermoplastic material is extruded to create the desired geometry. Many potential heat transfer applications of 3d printed parts, including the development of additively manufactured heat exchangers, exist. In addition, the availability of metal/polymer composite filaments, first used for applications such as tooling for injection molding applications and to improve wear resistance, could lead to increased performance 3d printed heat exchangers because of the higher thermal conductivity of the material. However, the exploitation of 3d printing for heat transfer applications is hindered by a lack of reliable thermal conductivity data for as-printed materials, which typically include significant void fractions. In this experimental study, an apparatus to measure the effective thermal conductivity of 3d printed composite materials was designed and fabricated. Its ability to accurately measure the thermal conductivity of polymers was validated using a sample of acrylic, whose conductivity is well understood. Finally, the thermal conductivities of various 3d printed polymer, metal/polymer composite, and carbon/polymer composite filaments were measured and are reported in this paper. The materials used are acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), stainless steel/PLA, Brass/PLA, and Bronze/PLA.

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