scholarly journals Fabrication of High-Performance CNT Reinforced Polymer Composite for Additive Manufacturing by Phase Inversion Technique

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 4007
Author(s):  
Pooyan Parnian ◽  
Alberto D’Amore
Keyword(s):  
Additive Manufacturing ◽  
Electrical Properties ◽  
Phase Inversion ◽  
High Performance ◽  
Inversion Method ◽  
Fused Filament Fabrication ◽  
Phase Inversion Technique ◽  
Key Factor ◽  
3D Printed ◽  
Thermal And Electrical Properties

Additive Manufacturing (AM) of polymer composites has enabled the fabrication of highly customized parts with notably mechanical properties, thermal and electrical conductivity compared to un-reinforced polymers. Employing the reinforcements was a key factor in improving the properties of polymers after being 3D printed. However, almost all the existing 3D printing methods could make the most of disparate fiber reinforcement techniques, the fused filament fabrication (FFF) method is reviewed in this study to better understand its flexibility to employ for the proposed novel method. Carbon nanotubes (CNTs) as a desirable reinforcement have a great potential to improve the mechanical, thermal, and electrical properties of 3D printed polymers. Several functionalization approaches for the preparation of CNT reinforced composites are discussed in this study. However, due to the non-uniform distribution and direction of reinforcements, the properties of the resulted specimen do not change as theoretically expected. Based on the phase inversion method, this paper proposes a novel technique to produce CNT-reinforced filaments to simultaneously increase the mechanical, thermal, and electrical properties. A homogeneous CNT dispersion in a dilute polymer solution is first obtained by sonication techniques. Then, the CNT/polymer filaments with the desired CNT content can be obtained by extracting the polymer’s solvent. Furthermore, optimizing the filament draw ratio can result in a reasonable CNT orientation along the filament stretching direction.

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...

scholarly journals Additive Manufacturing of Sensors for Military Monitoring Applications

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1455
Author(s):  
David T. Bird ◽  
Nuggehalli M. Ravindra
Keyword(s):  
Additive Manufacturing ◽  
High Performance ◽  
Sensor Technology ◽  
Distinct Advantage ◽  
Industrial Sectors ◽  
Sensor Fabrication ◽  
The Us ◽  
3D Printed ◽  
Maximum Protection ◽  
The Many

The US Department of Defense (DoD) realizes the many uses of additive manufacturing (AM) as it has become a common fabrication technique for an extensive range of engineering components in several industrial sectors. 3D Printed (3DP) sensor technology offers high-performance features as a way to track individual warfighters on the battlefield, offering protection from threats such as weaponized toxins, bacteria or virus, with real-time monitoring of physiological events, advanced diagnostics, and connected feedback. Maximum protection of the warfighter gives a distinct advantage over adversaries by providing an enhanced awareness of situational threats on the battle field. There is a need to further explore aspects of AM such as higher printing resolution and efficiency, with faster print times and higher performance, sensitivity and optimized fabrication to ensure that soldiers are more safe and lethal to win our nation’s wars and come home safely. A review and comparison of various 3DP techniques for sensor fabrication is presented.

scholarly journals The Surface Characterisation of Fused Filament Fabricated (FFF) 3D Printed PEEK/Hydroxyapatite Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3117
Author(s):  
Krzysztof Rodzeń ◽  
Mary Josephine McIvor ◽  
Preetam K. Sharma ◽  
Jonathan G. Acheson ◽  
Alistair McIlhagger ◽  
...  
Keyword(s):  
3D Printing ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Secondary Ion Mass Spectrometry ◽  
Fused Filament Fabrication ◽  
Surface Characterisation ◽  
X Ray ◽  
3D Printed

Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer which has found increasing application in orthopaedics and has shown a lot of promise for ‘made-to-measure’ implants via additive manufacturing approaches. However, PEEK is bioinert and needs to undergo surface modification to make it at least osteoconductive to ensure a more rapid, improved, and stable fixation that will last longer in vivo. One approach to solving this issue is to modify PEEK with bioactive agents such as hydroxyapatite (HA). The work reported in this study demonstrates the direct 3D printing of PEEK/HA composites of up to 30 weight percent (wt%) HA using a Fused Filament Fabrication (FFF) approach. The surface characteristics and in vitro properties of the composite materials were investigated. X-ray diffraction revealed the samples to be semi-crystalline in nature, with X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry revealing HA materials were available in the uppermost surface of all the 3D printed samples. In vitro testing of the samples at 7 days demonstrated that the PEEK/HA composite surfaces supported the adherence and growth of viable U-2 OS osteoblast like cells. These results demonstrate that FFF can deliver bioactive HA on the surface of PEEK bio-composites in a one-step 3D printing process.

scholarly journals Bonding between high-performance polymer processed by Fused Filament Fabrication and PEEK/carbon fiber laminate

2021 ◽  
Author(s):  
Isciane Caprais ◽  
Pierre Joyot ◽  
Emmanuel Duc ◽  
Simon Deseur
Keyword(s):  
Additive Manufacturing ◽  
Composite Structures ◽  
Composite Laminate ◽  
High Performance ◽  
Processing Conditions ◽  
Fused Filament Fabrication ◽  
Fiber Placement ◽  
High Performance Polymer ◽  
Automated Fiber Placement ◽  
The Impact

Automated fiber placement processes could be combined with additive manufacturing to produce more functionally complex composite structures with more flexibility. The challenge is to add functions or reinforcements to PEEK/carbon composite parts manufactured by automated fiber placement process, with additive manufacturing by fused filament fabrication. This consists of extruding a molten polymer through a nozzle to create a 3D part. Bonding between polymer filaments is a thermally driven phenomenon and determines the integrity and the final mechanical strength of the printed part. 3d-printing high performance polymers is still very challenging because they involve high thermal gradients during the process. The purpose of this work is to find a process window where the bonding strength is maximized between the composite laminate and the first layer of printed polymer, and inside the printed function as well. Experimental measurements of the temperature profiles at the interface between a composite substrate and 3d-printed PEI under different processing conditions were carried out. The interface was observed using microscopic sections. The methodology for studying the impact of printing parameters on the cohesion and adhesion of printed parts with a composite laminate is described. This work provides insights about the influence of processing conditions on the bond formation between high-performance polymer surfaces. It highlights the importance of controlling the thermal history of the materials all along the process.

scholarly journals Manufacturing a First Upper Molar Dental Forceps Using Continuous Fiber Reinforcement (CFR) Additive Manufacturing Technology with Carbon-Reinforced Polyamide

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2647
Author(s):  
Roland Told ◽  
Gyula Marada ◽  
Szilard Rendeki ◽  
Attila Pentek ◽  
Balint Nagy ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Medical Devices ◽  
Fiber Reinforcement ◽  
Strong Impact ◽  
Vertical Force ◽  
Continuous Fiber ◽  
Fused Filament Fabrication ◽  
Sem Images ◽  
3D Printed ◽  
Upper Molar

3D printing is an emerging and disruptive technology, supporting the field of medicine over the past decades. In the recent years, the use of additive manufacturing (AM) has had a strong impact on everyday dental applications. Despite remarkable previous results from interdisciplinary research teams, there is no evidence or recommendation about the proper fabrication of handheld medical devices using desktop 3D printers. The aim of this study was to critically examine and compare the mechanical behavior of materials printed with FFF (fused filament fabrication) and CFR (continuous fiber reinforcement) additive manufacturing technologies, and to create and evaluate a massive and practically usable right upper molar forceps. Flexural and torsion fatigue tests, as well as Shore D measurements, were performed. The tensile strength was also measured in the case of the composite material. The flexural tests revealed the measured force values to have a linear correlation with the bending between the 10 mm (17.06 N at 5000th cycle) and 30 mm (37.99 N at 5000th cycle) deflection range. The findings were supported by scanning electron microscopy (SEM) images. Based on the results of the mechanical and structural tests, a dental forceps was designed, 3D printed using CFR technology, and validated by five dentists using a Likert scale. In addition, the vertical force of extraction was measured using a unique molar tooth model, where the reference test was carried out using a standard metal right upper molar forceps. Surprisingly, the tests revealed there to be no significant differences between the standard (84.80 N ± 16.96 N) and 3D-printed devices (70.30 N ± 4.41 N) in terms of extraction force in the tested range. The results also highlighted that desktop CFR technology is potentially suitable for the production of handheld medical devices that have to withstand high forces and perform load-bearing functions.

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 Cylindrical Polyurethane Scaffold Fabricated Using the Phase Inversion Method: Influence of Process Parameters on Scaffolds’ Morphology and Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2977
Author(s):  
Aleksandra Kuźmińska ◽  
Dominika Kwarta ◽  
Tomasz Ciach ◽  
Beata A. Butruk-Raszeja
Keyword(s):  
Mechanical Properties ◽  
Polyvinyl Alcohol ◽  
Polymer Solution ◽  
Process Parameters ◽  
Phase Inversion ◽  
Young Modulus ◽  
Process Time ◽  
Inversion Method ◽  
Influence Of Process Parameters ◽  
Phase Inversion Technique

This work presents a method of obtaining cylindrical polymer structures with a given diameter (approx. 5 mm) using the phase inversion technique. As part of the work, the influence of process parameters (polymer hardness, polymer solution concentration, the composition of the non-solvent solution, process time) on the scaffolds’ morphology was investigated. Additionally, the influence of the addition of porogen on the scaffold’s mechanical properties was analyzed. It has been shown that the use of a 20% polymer solution of medium hardness (ChronoFlex C45D) and carrying out the process for 24 h in 0:100 water/ethanol leads to the achievement of repeatable structures with adequate flexibility. Among the three types of porogens tested (NaCl, hexane, polyvinyl alcohol), the most favorable results were obtained for 10% polyvinyl alcohol (PVA). The addition of PVA increases the range of pore diameters and the value of the mean pore diameter (9.6 ± 3.2 vs. 15.2 ± 6.4) while reducing the elasticity of the structure (Young modulus = 3.6 ± 1.5 MPa vs. 9.7 ± 4.3 MPa).

scholarly journals Molecularly Imprinted Polymer Pearls Obtained by Phase Inversion for the Selective Recognition of Hypericin

2019 ◽  
Vol 56 (2) ◽  
pp. 315-320
Author(s):  
Ana-Mihaela(Florea) Gavrila ◽  
Tanta-Verona Iordache ◽  
Teodor Sandu ◽  
Anamaria Zaharia ◽  
Anita-Laura Radu ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Phase Inversion ◽  
High Performance ◽  
Extraction Procedure ◽  
Inversion Method ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Wet Phase Inversion ◽  
Uv Visible ◽  
Phase Inversion Method

A facile and inexpensive approach was established to prepare spherical molecularly imprinted polymers with hypericin (H-MIPs) via the wet-phase inversion method. The H-MIPs were characterized by infrared spectroscopy and thermogravimetric analysis. High-performance liquid chromatography combined with UV-Visible spectroscopy were used to assess the efficiency of the extraction procedure and, furthermore, to investigate the recognition properties of the H-MIPs. Obtaining an imprinting factor of 3.38 for hypericin strongly indicated a successful formation of molecularly imprinted cavities onto the H-MIPs. A fair selectivity towards hypericin was tested in comparison to the interfering molecule pseudohypericin.

scholarly journals Fused Filament Fabrication, a New Fabrication Paradigm for 3D Printing Capacitive Sensors: Design, Fabrication, and Characterization for Liquid Level Measurements.

2021 ◽  
Author(s):  
Gianni Stano ◽  
Attilio Di Nisio ◽  
Anna Maria Lanzolla ◽  
Mattia Ragolia ◽  
Gianluca Percoco
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Flexible Substrate ◽  
Capacitive Sensor ◽  
Single Step ◽  
Liquid Level ◽  
Capacitive Sensors ◽  
Fused Filament Fabrication ◽  
3D Print ◽  
3D Printed

Abstract In recent years, the exploitation of Additive Manufacturing technologies for the fabrication of different kinds of sensors has abruptly increased: in particular, a growing interest for extrusion-based techniques has emerged. This research proposes the exploitation of Fused Filament Fabrication (FFF) process and two commercial materials (one flexible and one conductive) for the monolithic fabrication of a bendable, coplanar capacitive sensor. The whole sensor, consisting of a flexible substrate and two electrodes, has been fabricated in a single-step printing cycle: Design for Additive Manufacturing approach was used, setting out a methodology to direct 3D print thin and close tracks with conductive materials, in order to obtain high capacitance values measurable by common measurement instrumentations. Despite a huge exploitation of FFF technology for piezoresistive-based sensors, this manufacturing process has never been used for the fabrication of coplanar capacitive sensors since the manufacture of thin and close conductive tracks (key requirement in coplanar capacitive sensors) is a challenging task, mainly due to low manufacturability of extruded conductive beads with a high level of detail. Two versions of the sensor were developed: the first one with an embedded 3D printed coverage (ready to use) and the second one which requires a further manual post-processing to seal the electrodes. The main benefits related to the exploitation of FFF technology for these sensors are: i) the reduction of the number of different manufacturing processes employed, from at least two in traditional manufacturing approach up to one, ii) the exploitation of a cost-effective technology compared to traditional high-cost technologies employed (i.e. lithography, inkjet etc.) iii) the reduction of manual and assembly tasks (one of the proposed versions does not require any further task) , and iv) the cost-effectiveness of the sensors (in a range between 0.27 € and 0.38 €). The two developed prototypes have been tested demonstrating all their potentialities in the field of liquid level sensing, showing results consistent with the ones found in scientific literature: good sensitivity and high linearity and repeatability were proved when different liquids were employed. These 3D printed liquid level sensors have these features: i) flexible sensor, ii) the length is limited only by the machine workspace, iii) they can be either applied outside of the traditional reservoirs or embedded into the reservoirs (by 3D printing both the reservoir and sensor in the same manufacturing cycle), and iv) simple calibration.Finally, the bendability of these sensors paves the way toward their application for liquid level sensing into tanks with non-conventional shapes and for other application fields (i.e. soft robotics, non-invasive monitoring for biomedical applications).

Morphology of Micro-Porous Membrane of Waste Cigarette Butts Using Phase Inversion Method

2020 ◽  
Vol 860 ◽  
pp. 310-314
Author(s):  
Setianto ◽  
Liu Kin Men ◽  
Ayi Bahtiar ◽  
Bambang Mukti Wibawa ◽  
Darmawan Hidayat
Keyword(s):  
Phase Inversion ◽  
Surface Profile ◽  
Ultrafiltration Membrane ◽  
Raw Material ◽  
Synthesis Process ◽  
Inversion Method ◽  
Membrane Thickness ◽  
Membrane Synthesis ◽  
Cigarette Butts ◽  
Phase Inversion Technique

The separation technique in industrial processes with membrane technology is very important. Ultrafiltration membrane is one type of membrane using the principle of pressure-push force. One of the most commonly used ultrafiltration membrane materials is cellulose acetate (CA) membrane. The advantage of CA as a membrane material is that easily produced and its raw material which is a renewable source. The aim of this work is to present a simple experimental and simulation studies to illustrate the phase separation in the membrane synthesis process by the phase inversion technique. Simulation is used to determine the surface characteristics of the synthesized membrane. Two systems commonly used for the preparation of membrane synthesis are waste cigarette butts (WCB)/acetone/water. The effect of adding WCB concentrations (1 and 2 pieces) to the initial polymer casting solution was studied through simulation and compared with available experimental data. The experimental results are in accordance with the simulation was carried out. It shows that the surface profile of the membrane with the composition of the polymer film during precipitation can provide important information about the structure and substructure of the membrane formed. This also shows that the influence of CA concentration is closely related to changes in pore size on the membranes that are formed. The asymmetrical membrane structure prepared by the phase inversion process is influenced by the type and concentration of the polymer (WCB), solvent, membrane thickness and temperature and processing time.

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