The Effect of the Scanning Mode on the Finished Precision for SLA Technology

Stereo lithography apparatus is an advanced technology that uses photopolymers as the raw materials from which the prototypes are built. The RP manufacture system uses lasers or ultraviolet light to expose selectively the surface of the liquid resin and builds a three-dimensional part according its CAD model in a layer-by-layer manner. The absorption of energy causes photo-polymerization that changes the liquid resin into a solid, expanding the cured volume but shrinking simultaneously. The primary reason for the volume distortion and deformation of the stereo lithography apparatus part are the interlaminar stress generated by resin contraction. The volume shrinkage and curl distortion of the resin will lead to poor accuracy of the built prototype because the bending stress cannot be compensated for. Selecting a non-standard gear as experimental object and manufactured in the SCPS350B rapid prototyping machine. Four kinds of scanning mode, includes X-X mode, X-Y mode, XY mode and XY ST mode, are respectively carried out. From the results, it is found that SLA parameters, i.e. scanning mode and scanning speed significantly affect the forming precision of the prototype. The accuracy of the prototype with XYST mode is prior to the XY mode, and the X-Y mode is prior to the X-X mode. With the lower scanning speed and surface recoating process can further improve the finished precision.

Download Full-text

Natural Polymers for 3D Bioprinting of Organs

10.15688/nsr.jvolsu.2019.4.4 ◽

2020 ◽

pp. 30-40

Author(s):

Galina Sroslova ◽

Yuliya Zimina ◽

Elena Nesmeyanova ◽

Margarita Postnova

Keyword(s):

Raw Materials ◽

Sol Gel ◽

Three Dimensional ◽

Biologically Active ◽

Artificial Organs ◽

Gel Point ◽

Layer By Layer ◽

3D Bioprinting ◽

Natural Polymers ◽

Biological Origin

Three-dimensional (3D) bioprintingis a well-known promising technology for the production of artificial biological organs providing unprecedented versatility for manipulating cells and other biomaterials with precise control of their location in space. Over the past decade, a number of 3D bioprinting technologies have been developed. Unlike traditional manufacturing technologies, 3D bioprinting allows to produce individual or personalized fabric designs. This helps to deposit cells of the desired type with selected biomaterials and desired biologically active substances. Natural polymers play a leading role in maintaining cellular and biomolecular processes before, during, as well as after three-dimensional bioprinting. Polymers of biological origin can be extracted from natural raw materials by means of physical or chemical methods. These polymers are widely used as effective hydrogels for loading cells to form tissues, build a vascular, nervous, lymphatic network, and also to implement multiple biological, biochemical, physiological, biomedical and other functions. Any natural polymers that have a sol-gel phase transition (i.e., a gel point) under certain conditions can be printed using the automatic layer-by-layer deposition method. In fact, very few of them can be printed under various conditions (low temperature, without the help of physical, chemical, biochemical crosslinking of the incorporated polymer chains). Thus, not all natural polymers can meet all the basic requirements for 3D bioprinting. As a rule, natural polymers as the main component of various inks, which contain cells suspended in a specific medium, must meet several basic requirements for successful 3D bioprinting of organs, as well as clinical applications. These include biocompatibility, that is, non-toxic or without apparent toxicity; biodegradability (unlikenon-biodegradable polymers can be used as auxiliary structures); biostability with sufficiently high mechanical strength both at the time of processing and during operation; bioprinterness (workability). This review is devoted to modern research in the field of natural polymers used to print biological artificial organs.

Download Full-text

Investigation of Layer Thickness and Surface Roughness in Rapid Freeze Prototyping

Journal of Manufacturing Science and Engineering ◽

10.1115/1.1556401 ◽

2003 ◽

Vol 125 (3) ◽

pp. 556-563 ◽

Cited By ~ 23

Author(s):

Guanghua Sui ◽

Ming C. Leu

Keyword(s):

Surface Roughness ◽

Layer Thickness ◽

Three Dimensional ◽

Scanning Speed ◽

Layer By Layer ◽

Water Droplets ◽

Water Line ◽

Rapid Freeze Prototyping ◽

Cad Models ◽

Water Feed

Rapid Freeze Prototyping (RFP) builds three-dimensional ice parts according to CAD models by depositing and freezing water droplets in a layer-by-layer manner. This paper studies the layer thickness and surface roughness of ice parts built by the RFP process. The equations governing the water line formed by a sequence of water droplets are developed, and then a model of the water line is proposed by simplifying these equations based on our experimental condition. The analysis using this model shows that the cross-section of an ice line is circular, which is verified by experimental observations. Based on the analysis, equations for predicting layer thickness as a function of nozzle scanning speed, water feed rate, and water-ice contact angle in building vertical and slant walls by the RFP are derived and the predictions from these equations are shown to agree well with experimental measurements. The surface roughness of ice parts built by the RFP process is also studied.

Download Full-text

Where Is the Missing Matter?

3D Printing ◽

10.4018/978-1-5225-1677-4.ch007 ◽

2017 ◽

pp. 145-152

Author(s):

Tihomir Mitev

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

Industrial Revolution ◽

Raw Materials ◽

New Technology ◽

Three Dimensional ◽

Material Object ◽

Layer By Layer ◽

Solid Objects ◽

Thing In Itself

The additive manufacturing (or the popular 3D printing) is relatively new technology which opens new spaces for entrepreneurial imagination and promises next stage of the industrial revolution. It is creating three dimensional solid objects from a digital file. The printer transforms the file into a material object layer by layer, using different raw materials. Today, the additive manufacturing is successfully used in architecture, medicine and healthcare, light and heavy industries, education, etc. The paper analyses the roles of actors in manufacturing the objects. It starts with the Heideggerian questioning of technology (), searching for the causes of bringing into appearance of the 3D model. According to Heideggerian analysis the technology is represented as an ‘unveiling of the truth'. The paper suggests that the old understanding of matter as a thing-in-itself should be replaced by a new, flexible, fluid, concept of matter, which is more or less manipulable. The matter is no more an occasion for object's taking place. On the other hand, it seems 3D printing technology is reduced to mere means; a simple intermediary, a copier of ideas. From that perspective the paper questioning the problem of action in ANT and search how action and interaction is distributed and how actors constitutes themselves as well as their actor-world.

Download Full-text

Where is the Missing Matter?

International Journal of Actor-Network Theory and Technological Innovation ◽

10.4018/ijantti.2015010102 ◽

2015 ◽

Vol 7 (1) ◽

pp. 10-17 ◽

Cited By ~ 1

Author(s):

Tihomir Mitev

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

Industrial Revolution ◽

Raw Materials ◽

New Technology ◽

Three Dimensional ◽

Material Object ◽

Layer By Layer ◽

Solid Objects ◽

Thing In Itself

Download Full-text

3D Printing of High Viscosity Reinforced Silicone Elastomers

Polymers ◽

10.3390/polym13142239 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2239

Author(s):

Nicholas Rodriguez ◽

Samantha Ruelas ◽

Jean-Baptiste Forien ◽

Nikola Dudukovic ◽

Josh DeOtte ◽

...

Keyword(s):

Mechanical Properties ◽

High Performance ◽

New Technologies ◽

Three Dimensional ◽

High Viscosity ◽

Layer By Layer ◽

Silicone Elastomers ◽

Uv Curable ◽

Octet Truss ◽

Tunable Mechanical Properties

Recent advances in additive manufacturing, specifically direct ink writing (DIW) and ink-jetting, have enabled the production of elastomeric silicone parts with deterministic control over the structure, shape, and mechanical properties. These new technologies offer rapid prototyping advantages and find applications in various fields, including biomedical devices, prosthetics, metamaterials, and soft robotics. Stereolithography (SLA) is a complementary approach with the ability to print with finer features and potentially higher throughput. However, all high-performance silicone elastomers are composites of polysiloxane networks reinforced with particulate filler, and consequently, silicone resins tend to have high viscosities (gel- or paste-like), which complicates or completely inhibits the layer-by-layer recoating process central to most SLA technologies. Herein, the design and build of a digital light projection SLA printer suitable for handling high-viscosity resins is demonstrated. Further, a series of UV-curable silicone resins with thiol-ene crosslinking and reinforced by a combination of fumed silica and MQ resins are also described. The resulting silicone elastomers are shown to have tunable mechanical properties, with 100–350% elongation and ultimate tensile strength from 1 to 2.5 MPa. Three-dimensional printed features of 0.4 mm were achieved, and complexity is demonstrated by octet-truss lattices that display negative stiffness.

Download Full-text

Emergence of Polymeric Material Utilising Sustainable Radiation Curable Palm Oil-Based Products for Advanced Technology Applications

Polymers ◽

10.3390/polym13111865 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1865

Author(s):

Rida Tajau ◽

Rosiah Rohani ◽

Mohd Sofian Alias ◽

Nurul Huda Mudri ◽

Khairul Azhar Abdul Halim ◽

...

Keyword(s):

Palm Oil ◽

Raw Materials ◽

Raft Polymerization ◽

Polymeric Materials ◽

Fine Tuning ◽

Advanced Technology ◽

Radiation Processing ◽

Radiation Mechanisms ◽

Processing Technologies ◽

Technology Applications

In countries that are rich with oil palm, the use of palm oil to produce bio-based acrylates and polyol can be the most eminent raw materials used for developing new and advanced natural polymeric materials involving radiation technique, like coating resins, nanoparticles, scaffold, nanocomposites, and lithography for different branches of the industry. The presence of hydrocarbon chains, carbon double bonds, and ester bonds in palm oil allows it to open up the possibility of fine-tuning its unique structures in the development of novel materials. Cross-linking, reversible addition-fragmentation chain transfer (RAFT), polymerization, grafting, and degradation are among the radiation mechanisms triggered by gamma, electron beam, ultraviolet, or laser irradiation sources. These radiation techniques are widely used in the development of polymeric materials because they are considered as the most versatile, inexpensive, easy, and effective methods. Therefore, this review summarized and emphasized on several recent studies that have reported on emerging radiation processing technologies for the production of radiation curable palm oil-based polymeric materials with a promising future in certain industries and biomedical applications. This review also discusses the rich potential of biopolymeric materials for advanced technology applications.

Download Full-text

Exceptional Mechanical Properties and Heat Resistance of Photocurable Bismaleimide Ink for 3D Printing

Materials ◽

10.3390/ma14071708 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1708

Author(s):

Wenqiang Hua ◽

Qilang Lin ◽

Bo Qu ◽

Yanyu Zheng ◽

Xiaoying Liu ◽

...

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Heat Resistance ◽

Three Dimensional ◽

Mechanical And Thermal Properties ◽

Amino Group ◽

Building Models ◽

Fast Processing ◽

Forming Precision ◽

Complex Structural

Photosensitive resins used in three-dimensional (3D) printing are characterized by high forming precision and fast processing speed; however, they often possess poor mechanical properties and heat resistance. In this study, we report a photocurable bismaleimide ink with excellent comprehensive performance for stereolithography (SLA) 3D printing. First, the main chain of bismaleimide with an amino group (BDM) was synthesized, and then, the glycidyl methacrylate was grafted to the amino group to obtain the bismaleimide oligomer with an unsaturated double bond. The oligomers were combined with reaction diluents and photo-initiators to form photocurable inks that can be used for SLA 3D printing. The viscosity and curing behavior of the inks were studied, and the mechanical properties and heat resistance were tested. The tensile strength of 3D-printed samples based on BDM inks could reach 72.6 MPa (166% of that of commercial inks), glass transition temperature could reach 155 °C (205% of that of commercial inks), and energy storage modulus was 3625 MPa at 35 °C (327% of that of commercial inks). The maximum values of T-5%, T-50%, and Tmax of the 3D samples printed by BDM inks reached 351.5, 449.6, and 451.9 °C, respectively. These photocured BDM inks can be used to produce complex structural components and models with excellent mechanical and thermal properties, such as car parts, building models, and pipes.

Download Full-text

A guideline for 3D printing terminology in biomedical research utilizing ISO/ASTM standards

3D Printing in Medicine ◽

10.1186/s41205-021-00098-5 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Amy E. Alexander ◽

Nicole Wake ◽

Leonid Chepelev ◽

Philipp Brantner ◽

Justin Ryan ◽

...

Keyword(s):

3D Printing ◽

Medical Literature ◽

Three Dimensional ◽

Physical Object ◽

Medical Community ◽

Layer By Layer ◽

Digital File ◽

Standardized Terminology ◽

Standard Terms ◽

The Impact

AbstractFirst patented in 1986, three-dimensional (3D) printing, also known as additive manufacturing or rapid prototyping, now encompasses a variety of distinct technology types where material is deposited, joined, or solidified layer by layer to create a physical object from a digital file. As 3D printing technologies continue to evolve, and as more manuscripts describing these technologies are published in the medical literature, it is imperative that standardized terminology for 3D printing is utilized. The purpose of this manuscript is to provide recommendations for standardized lexicons for 3D printing technologies described in the medical literature. For all 3D printing methods, standard general ISO/ASTM terms for 3D printing should be utilized. Additional, non-standard terms should be included to facilitate communication and reproducibility when the ISO/ASTM terms are insufficient in describing expository details. By aligning to these guidelines, the use of uniform terms for 3D printing and the associated technologies will lead to improved clarity and reproducibility of published work which will ultimately increase the impact of publications, facilitate quality improvement, and promote the dissemination and adoption of 3D printing in the medical community.

Download Full-text

Three-dimensionally printed polycaprolactone/multicomponent bioactive glass scaffolds for potential application in bone tissue engineering

Biomedical glasses ◽

10.1515/bglass-2020-0006 ◽

2020 ◽

Vol 6 (1) ◽

pp. 57-69

Author(s):

Amirhosein Fathi ◽

Farzad Kermani ◽

Aliasghar Behnamghader ◽

Sara Banijamali ◽

Masoud Mozafari ◽

...

Keyword(s):

Tissue Engineering ◽

3D Printing ◽

Bone Tissue Engineering ◽

Bone Tissue ◽

Three Dimensional ◽

Layer By Layer ◽

Composite Scaffolds ◽

3D Printed ◽

Co Doped

AbstractOver the last years, three-dimensional (3D) printing has been successfully applied to produce suitable substitutes for treating bone defects. In this work, 3D printed composite scaffolds of polycaprolactone (PCL) and strontium (Sr)- and cobalt (Co)-doped multi-component melt-derived bioactive glasses (BGs) were prepared for bone tissue engineering strategies. For this purpose, 30% of as-prepared BG particles (size <38 μm) were incorporated into PCL, and then the obtained composite mix was introduced into a 3D printing machine to fabricate layer-by-layer porous structures with the size of 12 × 12 × 2 mm3.The scaffolds were fully characterized through a series of physico-chemical and biological assays. Adding the BGs to PCL led to an improvement in the compressive strength of the fabricated scaffolds and increased their hydrophilicity. Furthermore, the PCL/BG scaffolds showed apatite-forming ability (i.e., bioactivity behavior) after being immersed in simulated body fluid (SBF). The in vitro cellular examinations revealed the cytocompatibility of the scaffolds and confirmed them as suitable substrates for the adhesion and proliferation of MG-63 osteosarcoma cells. In conclusion, 3D printed composite scaffolds made of PCL and Sr- and Co-doped BGs might be potentially-beneficial bone replacements, and the achieved results motivate further research on these materials.

Download Full-text

Direct Patterning and Spontaneous Self-Assembly of Graphene Oxide via Electrohydrodynamic Jet Printing for Energy Storage and Sensing

Micromachines ◽

10.3390/mi11010013 ◽

2019 ◽

Vol 11 (1) ◽

pp. 13 ◽

Cited By ~ 2

Author(s):

Bin Zhang ◽

Jaehyun Lee ◽

Mincheol Kim ◽

Naeeung Lee ◽

Hyungdong Lee ◽

...

Keyword(s):

Graphene Oxide ◽

Energy Storage ◽

Self Assembly ◽

High Performance ◽

Three Dimensional ◽

Chemical Properties ◽

Layer By Layer ◽

Energy Storage Devices ◽

Laminar Structure ◽

Jet Printing

The macroscopic assembly of two-dimensional materials into a laminar structure has received considerable attention because it improves both the mechanical and chemical properties of the original materials. However, conventional manufacturing methods have certain limitations in that they require a high temperature process, use toxic solvents, and are considerably time consuming. Here, we present a new system for the self-assembly of layer-by-layer (LBL) graphene oxide (GO) via an electrohydrodynamic (EHD) jet printing technique. During printing, the orientation of GO flakes can be controlled by the velocity distribution of liquid jet and electric field-induced alignment spontaneously. Closely-packed GO patterns with an ordered laminar structure can be rapidly realized using an interfacial assembly process on the substrates. The surface roughness and electrical conductivity of the LBL structure were significantly improved compared with conventional dispensing methods. We further applied this technique to fabricate a reduced graphene oxide (r-GO)-based supercapacitor and a three-dimensional (3D) metallic grid hybrid ammonia sensor. We present the EHD-assisted assembly of laminar r-GO structures as a new platform for preparing high-performance energy storage devices and sensors.

Download Full-text