scholarly journals Radial Compressive Property and the Proof-of-Concept Study for Realizing Self-expansion of 3D Printing Polylactic Acid Vascular Stents with Negative Poisson’s Ratio Structure

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1357 ◽  
Author(s):  
Zichao Wu ◽  
Ji Zhao ◽  
Wenzheng Wu ◽  
Peipei Wang ◽  
Bofan Wang ◽  
...  
Keyword(s):  
3D Printing ◽  
Polylactic Acid ◽  
Deformation Temperature ◽  
Compressive Property ◽  
Recovery Ratio ◽  
Vascular Stent ◽  
Vascular Stents ◽  
3D Printed ◽  
Stent Diameter ◽  
Recovery Temperature

Biodegradable stents offer the potential to reduce the in-stent restenosis by providing support long enough for the vessel to heal. The polylactic acid (PLA) vascular stents with negative Poisson’s ratio (NPR) structure were manufactured by fused deposition modeling (FDM) 3D printing in this study. The effects of stent diameter, wall thickness and geometric parameters of arrowhead NPR structure on radial compressive property of 3D-printed PLA vascular stent were studied. The results showed that the decrease of stent diameter, the increase of wall thickness and the increase of the surface coverage could enhance the radial force (per unit length) of PLA stent. The radial and longitudinal size of PLA stent with NPR structure decreased simultaneously when the stent was crimped under deformation temperature. The PLA stent could expand in both radial and longitudinal direction under recovery temperature. When the deformation temperature and recovery temperature were both 65 °C, the diameter recovery ratio of stent was more than 95% and the maximum could reach 98%. The length recovery ratio was above 97%. This indicated the feasibility of utilizing the shape memory effect (SME) of PLA to realize the expansion of 3D-printed PLA vascular stent under temperature excitation.

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...

Mechanical Properties of 3D-Printed Wood-Plastic Composites

2018 ◽  
Vol 777 ◽  
pp. 499-507 ◽  
Author(s):  
Ossi Martikka ◽  
Timo Kärki ◽  
Qing Ling Wu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
3D Printing ◽  
Impact Strength ◽  
Polylactic Acid ◽  
Wood Plastic Composite ◽  
Wood Plastic Composites ◽  
Plastic Composite ◽  
Plastic Composites ◽  
3D Printed

3D printing has rapidly become popular in both industry and private use. Especially fused deposition modeling has increased its popularity due to its relatively low cost. The purpose of this study is to increase knowledge in the mechanical properties of parts made of wood-plastic composite materials by using 3D printing. The tensile properties and impact strength of two 3D-printed commercial wood-plastic composite materials are studied and compared to those made of pure polylactic acid. Relative to weight –mechanical properties and the effect of the amount of fill on the properties are also determined. The results indicate that parts made of wood-plastic composites have notably lower tensile strength and impact strength that those made of pure polylactic acid. The mechanical properties can be considered sufficient for low-stress applications, such as visualization of prototypes and models or decorative items.

scholarly journals DESIGN OF A 3D-PRINTED THREE-CLAW ROBOTIC GRIPPER END-EFFECTOR

2021 ◽  
Vol 11 (4) ◽  
pp. 70-79
Author(s):  
Dino Dominic Forte Ligutan ◽  
Argel Alejandro Bandala ◽  
Jason Limon Española ◽  
Richard Josiah Calayag Tan Ai ◽  
Ryan Rhay Ponce Vicerra ◽  
...  
Keyword(s):  
3D Printing ◽  
Polylactic Acid ◽  
Grip Force ◽  
Thermoplastic Polyurethane ◽  
Robotic Arm ◽  
End Effector ◽  
Design Considerations ◽  
3D Printed ◽  
Materials Used ◽  
Metal Work

The development of a novel 3D-printed three-claw robotic gripper shall be described in this paper with the goal of incorporating various design considerations. Such considerations include the grip reliability and stability, grip force maximization, wide object grasping capability. Modularization of its components is another consideration that allows its parts to be easily machined and reusable. The design was realized by 3D printing using a combination of tough polylactic acid (PLA) material and thermoplastic polyurethane (TPU) material. In practice, additional tolerances were also considered for 3D printing of materials to compensate for possible expansion or shrinkage of the materials used to achieve the required functionality. The aim of the study is to explore the design and eventually deploy the three-claw robotic gripper to an actual robotic arm once its metal work fabrication is finished.

Enhancement of the Compressive Strength of 3D-Printed Polylactic Acid(PLA) by Controlling Internal Pattern

2021 ◽  
Vol 1023 ◽  
pp. 75-81
Author(s):  
Aappo Mustakangas ◽  
Atef Hamada ◽  
Antti Järvenpää
Keyword(s):  
Compressive Strength ◽  
3D Printing ◽  
Polylactic Acid ◽  
Optical Microscope ◽  
Fused Filament Fabrication ◽  
Loading Direction ◽  
Compressive Flow ◽  
3D Printed ◽  
Cost Efficient ◽  
Loading Axis

Cost-efficient 3D-printing can create a lot of new opportunities in engineering as it enables rapid prototyping of models and functional parts. In the present study, Polylactic acid (PLA) cubic specimens with different types of infill patterns (IPs), rectilinear, grid and cuboid, were additively manufactured by Fused Filament Fabrication 3D-printing. The PLA cubes are fabricated with one perimeter and different IPs density (10, 20, and 30%). Subsequently, the compressive strengths of the PLA materials were measured in two loading directions, i.e., the layers building direction is parallel (PD) to the loading axis and perpendicular (ND) to the loading direction. An optical microscope was used to examine the deformed IPs in both loading directions. The compressive flow stress curves of the PLA cubes infilled with rectilinear and grid patterns exhibited strong fluctuations with lower compressive strengths in the loading direction along ND. The PLA with 30% grid IP revealed a superior strength of ~12 kN in the loading direction along PD. On the contrary, the same material exhibited a worst compressive strength 3 kN along ND.

scholarly journals Effect of Porosity and Crystallinity on 3D Printed PLA Properties

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1487 ◽  
Author(s):  
Yuhan Liao ◽  
Chang Liu ◽  
Bartolomeo Coppola ◽  
Giuseppina Barra ◽  
Luciano Di Maio ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Polylactic Acid ◽  
Complex Geometry ◽  
Fused Filament Fabrication ◽  
3D Printed ◽  
Physical Changes ◽  
Crystalline Forms

Additive manufacturing (AM) is a promising technology for the rapid tooling and fabrication of complex geometry components. Among all AM techniques, fused filament fabrication (FFF) is the most widely used technique for polymers. However, the consistency and properties control of the FFF product remains a challenging issue. This study aims to investigate physical changes during the 3D printing of polylactic acid (PLA). The correlations between the porosity, crystallinity and mechanical properties of the printed parts were studied. Moreover, the effects of the build-platform temperature were investigated. The experimental results confirmed the anisotropy of printed objects due to the occurrence of orientation phenomena during the filament deposition and the formation both of ordered and disordered crystalline forms (α and δ, respectively). A heat treatment post-3D printing was proposed as an effective method to improve mechanical properties by optimizing the crystallinity (transforming the δ form into the α one) and overcoming the anisotropy of the 3D printed object.

scholarly journals Preparation and 3D-printing of highly conductive polylactic acid/carbon nanotube nanocomposites via local enrichment strategy

RSC Advances ◽  
2019 ◽  
Vol 9 (51) ◽  
pp. 29980-29986 ◽  
Author(s):  
Shaohong Shi ◽  
Yinghong Chen ◽  
Jingjing Jing ◽  
Lu Yang
Keyword(s):  
Carbon Nanotube ◽  
3D Printing ◽  
Polylactic Acid ◽  
3D Printed ◽  
Local Enrichment ◽  
Enrichment Strategy

A novel local enrichment strategy was adopted to fabricate the highly conductive carbon nanotube/polylactic acid 3D-printed parts.

scholarly journals Printability and properties of 3D-printed poplar fiber/polylactic acid biocomposite

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 2774-2788
Author(s):  
Zhaozhe Yang ◽  
Xinhao Feng ◽  
Min Xu ◽  
Denis Rodrigue
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Rheological Properties ◽  
Layer Thickness ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Longitudinal Stripe ◽  
3D Printed ◽  
First Time ◽  
Printing Parameters

To efficiently and economically utilize a wood-plastic biocomposite, an eco-friendly biocomposite was prepared using modified poplar fiber and polylactic acid (PLA) via 3D printing technology for the first time. First, the effects of poplar fiber (0, 1, 3, 5, 7, and 9%) on the mechanical and rheological properties of the printed biocomposites were investigated. Subsequently, the printing parameters, including printing temperature, speed, and layer thickness, were optimized to obtain the biocomposite with superior properties. Finally, four printing orientations were applied to the biocomposite based on the optimized printing parameters to study the effect of filament orientation on the properties of the biocomposite. Favorable printability and mechanical properties of the biocomposite were obtained at 5% poplar fiber. The optimal printing temperature of 220 °C, speed of 40 mm/s, and layer thickness of 0.2 mm were obtained to produce the desired mechanical properties of the biocomposite with the printing orientation in a longitudinal stripe. However, the printing parameters should be chosen according to the applications, where different physical and mechanical properties are needed to achieve efficient and economical utilization of the biocomposites.

scholarly journals 3D-printed monolithic biofilters based on a polylactic acid (PLA) – hydroxyapatite (HAp) composite for heavy metal removal from an aqueous medium

RSC Advances ◽  
2021 ◽  
Vol 11 (51) ◽  
pp. 32408-32418
Author(s):  
Natalia Fijoł ◽  
Hani Nasser Abdelhamid ◽  
Binsi Pillai ◽  
Stephen A. Hall ◽  
Nebu Thomas ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Phase Separation ◽  
3D Printing ◽  
Polylactic Acid ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Three Dimensional ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
3D Printed

Water purification filters based on polylactic acid functionalised with hydroxyapatite were prepared by solvent-assisted blending and thermally induced phase separation (TIPS), extruded into filaments and processed via three-dimensional (3D) printing.

scholarly journals 3D printed PLA Army-Navy retractors when used as linear retractors yield clinically acceptable tolerances

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Joshua V. Chen ◽  
Alexis B. C. Dang ◽  
Carlin S. Lee ◽  
Alan B. C. Dang
Keyword(s):  
3D Printing ◽  
Polylactic Acid ◽  
Low Cost ◽  
Optimal Designs ◽  
Material Cost ◽  
Resource Poor ◽  
3D Printed ◽  
Strength Material ◽  
Printing Parameters ◽  
Printing Time

Abstract Background Modern low-cost 3D printing technologies offer the promise of access to surgical tools in resource scarce areas, however optimal designs for manufacturing have not yet been established. We explore how the optimization of 3D printing parameters when manufacturing polylactic acid filament based Army-Navy retractors vastly increases the strength of retractors, and investigate sources of variability in retractor strength, material cost, printing time, and parameter limitations. Methods Standard retractors were printed from various polylactic acid filament spools intra-manufacturer and inter-manufacturer to measure variability in retractor strength. Printing parameters were systematically varied to determine optimum printing parameters. These parameters include retractor width, thickness, infill percentage, infill geometry, perimeter number, and a reinforced joint design. Estimated retractor mass from computer models allows us to estimate material cost. Results We found statistically significant differences in retractor strength between spools of the same manufacturer and between manufacturers. We determined the true strength optimized retractor to have 30% infill, 3 perimeters, 0.25 in. thickness, 0.75 in. width, and has “Triangle” infill geometry and reinforced joints, failing at more than 15X the threshold for clinically excessive retraction and costs $1.25 USD. Conclusions The optimization of 3D printed Army-Navy retractors greatly improve the efficacy of this instrument and expedite the adoption of 3D printing technology in many diverse fields in medicine not necessarily limited to resource poor settings.

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