Effects of 3D Printing-Line Directions for Stretchable Sensor Performances

Health monitoring sensors that are attached to clothing are a new trend of the times, especially stretchable sensors for human motion measurements or biological markers. However, price, durability, and performance always are major problems to be addressed and three-dimensional (3D) printing combined with conductive flexible materials (thermoplastic polyurethane) can be an optimal solution. Herein, we evaluate the effects of 3D printing-line directions (45°, 90°, 180°) on the sensor performances. Using fused filament fabrication (FDM) technology, the sensors are created with different print styles for specific purposes. We also discuss some main issues of the stretch sensors from Carbon Nanotube/Thermoplastic Polyurethane (CNT/TPU) and FDM. Our sensor achieves outstanding stability (10,000 cycles) and reliability, which are verified through repeated measurements. Its capability is demonstrated in a real application when detecting finger motion by a sensor-integrated into gloves. This paper is expected to bring contribution to the development of flexible conductive materials—based on 3D printing.

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Optimization of the 3D Printing Parameters for Tensile Properties of Specimens Produced by Fused Filament Fabrication of 17-4PH Stainless Steel

Materials ◽

10.3390/ma13030774 ◽

2020 ◽

Vol 13 (3) ◽

pp. 774 ◽

Cited By ~ 7

Author(s):

Damir Godec ◽

Santiago Cano ◽

Clemens Holzer ◽

Joamin Gonzalez-Gutierrez

Keyword(s):

Stainless Steel ◽

3D Printing ◽

Tensile Properties ◽

Layer Thickness ◽

Flow Rate ◽

Three Dimensional ◽

Steel Powder ◽

Extrusion Temperature ◽

Fused Filament Fabrication ◽

Printing Parameters

Fused filament fabrication (FFF) combined with debinding and sintering could be an economical process for three-dimensional (3D) printing of metal parts. In this paper, compounding, filament making, and FFF processing of feedstock material with 55% vol. of 17-4PH stainless steel powder in a multicomponent binder system are presented. The experimental part of the paper encompasses central composite design for optimization of the most significant 3D printing parameters (extrusion temperature, flow rate multiplier, and layer thickness) to obtain maximum tensile strength of the 3D-printed specimens. Here, only green specimens were examined in order to be able to determine the optimal parameters for 3D printing. The results show that the factor with the biggest influence on the tensile properties was flow rate multiplier, followed by the layer thickness and finally the extrusion temperature. Maximizing all three parameters led to the highest tensile properties of the green parts.

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3D Printing in Dentistry—State of the Art

Operative Dentistry ◽

10.2341/18-229-l ◽

2020 ◽

Vol 45 (1) ◽

pp. 30-40 ◽

Cited By ~ 14

Author(s):

A Kessler ◽

R Hickel ◽

M Reymus

Keyword(s):

3D Printing ◽

Clinical Application ◽

Industrial Revolution ◽

Rapid Development ◽

Selective Laser Sintering ◽

Three Dimensional ◽

Fused Filament Fabrication ◽

Digital Light Processing ◽

Materials Used ◽

Binder Jetting

SUMMARY Three-dimensional (3D) printing is a rapidly developing technology that has gained widespread acceptance in dentistry. Compared to conventional (lost-wax technique) and subtractive computer numeric controlled methods, 3D printing offers process engineering advantages. Materials such as plastics, metals, and ceramics can be manufactured using various techniques. 3D printing was introduced over three decades ago. Today, it is experiencing rapid development due to the expiration of many patents and is often described as the key technology of the next industrial revolution. The transition to its clinical application in dentistry is highly dependent on the available materials, which must not only provide the required accuracy but also the necessary biological and physical properties. The aim of this work is to provide an up-to-date overview of the different printing techniques: stereolithography, digital light processing, photopolymer jetting, material jetting, binder jetting, selective laser sintering, selective laser melting, and fused filament fabrication. Additionally, particular attention is paid to the materials used in dentistry and their clinical application.

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An Apparatus Designed for Coating and Coloration of Filaments Used in Fused Filament Fabrication (FFF) 3D Printing

Recent Patents on Mechanical Engineering ◽

10.2174/2212797614666210208224615 ◽

2021 ◽

Vol 14 ◽

Author(s):

Piyush Chohan ◽

Aniket Yadav ◽

Ranvijay Kumar ◽

Raman Kumar ◽

Jasgurpreet Singh Chohan

Keyword(s):

3D Printing ◽

Surface Finish ◽

Three Dimensional ◽

Layer By Layer ◽

Fused Filament Fabrication ◽

Outlet Port ◽

Inlet Port ◽

Uniform Coating ◽

Good Surface ◽

Good Surface Finish

Background: Three dimensional (3D) printing is emerging technology, capable of manufacturing a solid layer by layer. With the advancements of materials for 3D printing, this technology is applicable in almost every sector. But in accordance with the product requirements we need to modify the mechanical properties of material. To achieve good surface finish we require coating of filament. For this purpose an apparatus is designed for coating of material over a filament, which is capable of coating filaments uniformly and with automated process. Objective: The objective of present invention is directed to a filament feeding device for applying uniform coating on a filament in order to make 3D solid objects with good quality finishing, thereby eliminating the chances of strains and imperfect coating on the filament. Methods: The present invention relates to a filament feeding device, comprising a container equipped within the device for storing a chemical solution in a liquefied form, an inlet port fabricated on the container for inserting a filament inside the container, plurality of relief valves placed at a bottom portion of the container for controlling the leakage of the filaments during insertion of the filaments. A stepper motor in association with a blade equipped within the container to rotate the main extruder of a 3D printer, and an outlet port designed opposite to the inlet port for discharging the filament from the container for 3D printing of the filament in order to manufacture the solid object. Results: The apparatus makes it easy for coating and coloration of materials to make the reinforced composite filaments. As this apparatus provides uniform coating of material on the filaments, the product printed by filaments have good surface finish. Conclusion: The proposed method can reduce coating time and printing time. This work provides meaningful implication to researchers who are doing research in the domain of additive manufacturing.

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Sustainable Additive Manufacturing: Mechanical Response of Polyethylene Terephthalate Glycol over Multiple Recycling Processes

Materials ◽

10.3390/ma14051162 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1162

Author(s):

Nectarios Vidakis ◽

Markos Petousis ◽

Lazaros Tzounis ◽

Sotirios A. Grammatikos ◽

Emmanouil Porfyrakis ◽

...

Keyword(s):

Additive Manufacturing ◽

3D Printing ◽

Polyethylene Terephthalate ◽

Mechanical Response ◽

Three Dimensional ◽

Thermal Response ◽

Fused Filament Fabrication ◽

Hardness Tests ◽

Multiple Recycling ◽

A Minor

The continuous demand for thermoplastic polymers in a great variety of applications, combined with an urgent need to minimize the quantity of waste for a balanced energy-from-waste strategy, has led to increasing scientific interest in developing new recycling processes for plastic products. Glycol-modified polyethylene terephthalate (PETG) is known to have some enhanced properties as compared to polyethylene terephthalate (PET) homopolymer; this has recently attracted the interest from the fused filament fabrication (FFF) three-dimensional (3D) printing community. PET has shown a reduced ability for repeated recycling through traditional processes. Herein, we demonstrate the potential for using recycled PETG in consecutive 3D printing manufacturing processes. Distributed recycling additive manufacturing (DRAM)-oriented equipment was chosen in order to test the mechanical and thermal response of PETG material in continuous recycling processes. Tensile, flexure, impact strength, and Vickers micro-hardness tests were carried out for six (6) cycles of recycling. Finally, Raman spectroscopy as well as thermal and morphological analyses via scanning electron microscopy (SEM) fractography were carried out. In general, the results revealed a minor knockdown effect on the mechanical properties as well as the thermal properties of PETG following the process proposed herein, even after six rounds of recycling.

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Evaluation of the Mechanical Properties of Porous Thermoplastic Polyurethane Obtained by 3D Printing for Protective Gear

Advances in Materials Science and Engineering ◽

10.1155/2019/5838361 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Hyojeong Lee ◽

Ran-i Eom ◽

Yejin Lee

Keyword(s):

Tensile Strength ◽

3D Printing ◽

Thermoplastic Polyurethane ◽

Three Dimensional ◽

Protective Equipment ◽

Shock Absorption ◽

Protective Gear ◽

Compression Properties ◽

Impact Deformation ◽

3D Printed

Three-dimensional (3D) printing is an efficient and sustainable technology useful in various manufacturing fields. The aim of this study was to investigate the applicability of thermoplastic polyurethane (TPU) as a 3D printing material and the conditions related to the use of TPU as personal protective equipment. The tensile strength, shock absorption, and compressibility were evaluated for different infill and thickness conditions. An increase in the infill rate led to an increase in the tensile strength, regardless of the sample thickness. Similarly, the compression energy increased as the infill increased. Both the shock absorption and compression properties increased as the thickness decreased under identical infill conditions. The actual shock absorption test data were compared to the results of structural analyses, which confirmed the potential for predicting impact deformation through the analysis of the tensile characteristics and the basic properties of a 3D printed material.

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Processing of Polyester-Urethane Filament and Characterization of FFF 3D Printed Elastic Porous Structures with Potential in Cancellous Bone Tissue Engineering

Materials ◽

10.3390/ma13194457 ◽

2020 ◽

Vol 13 (19) ◽

pp. 4457

Author(s):

Agnieszka Haryńska ◽

Iga Carayon ◽

Paulina Kosmela ◽

Anna Brillowska-Dąbrowska ◽

Marcin Łapiński ◽

...

Keyword(s):

Tissue Engineering ◽

3D Printing ◽

Bone Tissue ◽

Cancellous Bone ◽

Thermoplastic Polyurethane ◽

Porous Structures ◽

Fused Filament Fabrication ◽

Polyester Urethane ◽

Tissue Structures

This paper addresses the potential of self-made polyester-urethane filament as a candidate for Fused Filament Fabrication (FFF)-based 3D printing (3DP) in medical applications. Since the industry does not provide many ready-made solutions of medical-grade polyurethane filaments, we undertook research aimed at presenting the process of thermoplastic polyurethane (TPU) filament formation, detailed characteristics, and 3DP of specially designed elastic porous structures as candidates in cancellous tissue engineering. Additionally, we examined whether 3D printing affects the structure and thermal stability of the filament. According to the obtained results, the processing parameters leading to the formation of high-quality TPU filament (TPU_F) were captured. The results showed that TPU_F remains stable under the FFF 3DP conditions. The series of in vitro studies involving long- and short-term degradation (0.1 M phosphate-buffered saline (PBS); 5 M sodium hydroxide (NaOH)), cytotoxicity (ISO 10993:5) and bioactivity (simulated body fluid (SBF) incubation), showed that TPU printouts possessing degradability of long-term degradable tissue constructs, are biocompatible and susceptible to mineralization in terms of hydroxyapatite (HAp) formation during SBF exposure. The formation of HAp on the surface of the specially designed porous tissue structures (PTS) was confirmed by scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) studies. The compression test of PTS showed that the samples were strengthened due to SBF exposure and deposited HAp on their surface. Moreover, the determined values of the tensile strength (~30 MPa), Young’s modulus (~0.2 GPa), and compression strength (~1.1 MPa) allowed pre-consideration of TPU_F for FFF 3DP of cancellous bone tissue structures.

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Fabrication of ABS/Graphene Oxide Composite Filament for Fused Filament Fabrication (FFF) 3D Printing

Advances in Materials Science and Engineering ◽

10.1155/2018/2830437 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 11

Author(s):

C. Aumnate ◽

A. Pongwisuthiruchte ◽

P. Pattananuwat ◽

P. Potiyaraj

Keyword(s):

Graphene Oxide ◽

3D Printing ◽

3D Model ◽

Three Dimensional ◽

Emerging Technology ◽

Layer By Layer ◽

Fused Filament Fabrication ◽

Dry Mixing ◽

Mixing Method ◽

Composite Filament

Additive manufacturing, the so-called three-dimensional (3D) printing, is a revolutionary emerging technology. Fused filament fabrication (FFF) is the most used 3D printing technology in which the melted filament is extruded through the nozzle and builds up layer by layer onto the build platform. The layers are then fused together and solidified into final parts. Graphene-based materials have been positively incorporated into polymers for innovative applications, such as for the mechanical, thermal, and electrical enhancement. However, to reach optimum properties, the graphene fillers are necessary to be well dispersed in polymers matrix. This study aims to emphasise the interest of producing ABS/graphene oxide (GO) composites for 3D printing application. The ABS/GO composite filaments were produced using dry mixing and solvent mixing methods before further melt extruded to investigate the proper way to disperse GO into ABS matrix. The ABS/GO composite filament with 2 wt.% of GO, prepared from the solvent mixing method, was successfully printed into a 3D model. By adding GO, the tensile strength and Young’s modulus of ABS can be enhanced. However, the ABS/GO composite filament that was prepared via the dry mixing method failed to print. This could be attributed to the aggregation of GO, leading to the die clogging and failure of the printing process.

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Automated draping analysis of 3D printed flexible isogrid structures for textile applications

Textile Research Journal ◽

10.1177/00405175211006210 ◽

2021 ◽

pp. 004051752110062

Author(s):

Jordan Kalman ◽

Kazem Fayazbakhsh ◽

Danielle Martin

Keyword(s):

Image Processing ◽

3D Printing ◽

Large Range ◽

Thermoplastic Polyurethane ◽

Small Scale ◽

Fused Filament Fabrication ◽

3D Print ◽

3D Printed

Fused filament fabrication (FFF) 3D printing can be used for manufacturing flexible isogrid structures. This work presents a novel draping analysis of flexible 3D printed isogrids from thermoplastic polyurethane (TPU) using image processing. A small-scale multi-camera automated draping apparatus (ADA) is designed and used to characterize draping behavior of 3D printed isogrid structures based on draping coefficient (DC) and mode. Circular specimens are designed and 3D printed that accommodate up to eight additional weights on their perimeters to enhance draping. Five infill patterns, three infill percentages, and three loading cases are explored to evaluate their impact on specimens’ draping coefficient and mode, resulting in 45 tests. The range of DCs in this study is 21.9% to 91.5%, and a large range of draping modes is observed. For the lowest infill percentage, specimen mass is not the sole contributor to the DC values and the infill pattern has a significant impact for the three loading cases. Considering draping modes, the maximum number of convex and concave nodes observed for 25% infill specimens with added weights is three. The draping behavior characterization developed in this study can be followed to design and 3D print new flexible isogrids with textile applications.

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Design of ROV Training Simulator

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.130-134.170 ◽

2011 ◽

Vol 130-134 ◽

pp. 170-174

Author(s):

Xin Ge ◽

Wei Guo ◽

Zhi Yang Li

Keyword(s):

Virtual Reality ◽

Control System ◽

Dynamic Simulation ◽

Physical Simulation ◽

Three Dimensional ◽

Training Simulator ◽

Virtual Reality Technology ◽

Sea Trial ◽

And Performance ◽

The Times

Semi-physical simulation technology and virtual reality technology in real-time three-dimensional dynamic simulation of remote operated vehicle, and a set of real ROV control system are utilized to design a ROV Training Simulator. This ROV Training Simulator can not only be used to train ROV operators, reduce the times of sea trial,but also can verify the function and performance of real ROV control system.

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A Multi-Criteria Assessment Strategy for 3D Printed Porous Polyetheretherketone (PEEK) Patient-Specific Implants for Orbital Wall Reconstruction

Journal of Clinical Medicine ◽

10.3390/jcm10163563 ◽

2021 ◽

Vol 10 (16) ◽

pp. 3563

Author(s):

Neha Sharma ◽

Dennis Welker ◽

Soheila Aghlmandi ◽

Michaela Maintz ◽

Hans-Florian Zeilhofer ◽

...

Keyword(s):

3D Printing ◽

Three Dimensional ◽

Patient Specific ◽

Fused Filament Fabrication ◽

Decision Matrix ◽

Maximum Deformation ◽

Patient Specific Implants ◽

High Durability ◽

Orbital Wall ◽

3D Printed

Pure orbital blowout fractures occur within the confines of the internal orbital wall. Restoration of orbital form and volume is paramount to prevent functional and esthetic impairment. The anatomical peculiarity of the orbit has encouraged surgeons to develop implants with customized features to restore its architecture. This has resulted in worldwide clinical demand for patient-specific implants (PSIs) designed to fit precisely in the patient’s unique anatomy. Material extrusion or Fused filament fabrication (FFF) three-dimensional (3D) printing technology has enabled the fabrication of implant-grade polymers such as Polyetheretherketone (PEEK), paving the way for a more sophisticated generation of biomaterials. This study evaluates the FFF 3D printed PEEK orbital mesh customized implants with a metric considering the relevant design, biomechanical, and morphological parameters. The performance of the implants is studied as a function of varying thicknesses and porous design constructs through a finite element (FE) based computational model and a decision matrix based statistical approach. The maximum stress values achieved in our results predict the high durability of the implants, and the maximum deformation values were under one-tenth of a millimeter (mm) domain in all the implant profile configurations. The circular patterned implant (0.9 mm) had the best performance score. The study demonstrates that compounding multi-design computational analysis with 3D printing can be beneficial for the optimal restoration of the orbital floor.

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