For Fused Deposition Modeling Research Articles

Performance of bioresorbable peptide incorporated polymers produced for fused deposition modelling (FDM)

The use of biomaterials in additive manufacturing (AM) of medical devices has gained significant attention over the years, especially in areas such as wound care and orthopedics. This study aims to investigate the performance of bioresorbable peptide-incorporated polymers produced for fused deposition modelling (FDM) process. Herein, we report FDM 3D Printing process of bioactive polymers comprising polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA) or polylactic acid (PLA) or blended with peptide–containing brush copolymers bearing similar synthetic polymer side chains. Mechanical, thermal and rheological properties of the materials were carried out and we report that the incorporation of bioactive polymers into these biodegradable polymers does not result in significant changes to glass transition temperature, melt temperature, tensile properties of the base polymers. However, it was observed that flexural and rheological properties altered significantly. This study provides an insight into the thermomechanical performance of bioresorbable peptide-incorporated polymers for FDM utilization which allows for their use potential in medical device fabrication.

Recent development of poly (lactic acid) blends with a thermoplastic elastomer compatibilised for fused deposition modelling (FDM) 3D printing

Recent development of poly (lactic acid) blends with a thermoplastic elastomer compatibilised for fused deposition modelling (FDM) 3D printing

Silk-inspired architectured filament with enhanced stiffness and toughness for Fused deposition modelling (FDM)

Architectured materials, those capable of manipulating the spatial configurations of two or more material phases, have recently gained substantial attention, primarily due to their unprecedented material properties (e.g., exceptional strength-to-weight ratio and intriguing negative Poisson's ratio). Most architectured materials draw inspiration from the microstructure of natural solutions. One of fascinating examples are spider silk and cocoon silk. Their multimaterial core-shell fibrous structure exhibits remarkable mechanical properties—high stiffness, strength, and toughness. In this study, silk-inspired dual-phase Core-Shell Architectured Filament (CSAF), which combines a rigid Polylactic Acid (PLA) core with a soft Thermoplastic Polyurethane (TPU) shell, was developed as feedstock for additive manufacturing. The mechanical testing of dual-phase CASF printed samples reveal intriguing results. Notably, the optimized CASF in this study, whose volume fraction of rigid core was set as 52 %, was observed a substantial improvement of the printed specimens in initial stiffness and energy absorption capacity—up to a remarkable 14-fold increase in initial stiffness and a ∼9 % enhancement in energy absorption when compared to the pure TPU filament. To gain a deeper understanding of the synergistic effects arising from geometrical and material configurations on the structure's damage mechanism, a theoretical model of this core-shell structure was developed. Computational models have been built to validate theoretical model, and the results from finite element analysis are in excellent agreement with experimental results. These discoveries offer valuable insights to enhance mechanical performance of the feedstock for additive manufacturing.

Influence of Hydroxyapatite Particle Size on the Flowability of PLA/HA Filament

Advanced bioactive ceramic materials, Hydroxyapatite (HA) and Polylactic Acid (PLA) are common in bone regeneration implants. As demand for customised implant products increases, research increasingly focuses on developing composite filament manufacturing technology. However, creating PLA/HA composite filament faces challenges, including clumping HA particles and uneven flowability. The brittleness of the filament properties makes it unsuitable for Fused Deposition Modelling (FDM) printing, causing inconsistent extrusion and reduced filament strength. The purpose of this study is to compare the effectiveness of microHAs (m-HAs) and nanoHAs (n-HAs) in the production of filament composite fibers, based on the flowability assessment. The particle size of the micro-HA was reduced to nano by a ball mill process using 4 mL ethanol and the ball-powder ratio of 5:1, which was verified by the particle size analyzer. The feedstock comprises 79.5 wt.% PLA, 19.5 wt.% HA and 1 wt.% impact modifier (IMK) was mixed and rheological tested (130 ℃ to 150 ℃, shear rate: 20-1000 s-1) to achieve pseudoplastic behaviour (n<1). The rheological tests showed that both feedstocks exhibited pseudoplastic behaviour (n<1) across all temperatures studied. The properties of the feedstock were observed by scanning electron microscopy (SEM), and tensile tests evaluated the filament strength. The investigation found that nano-sized HA filament has 24% higher strength than micro-sized PLA/HA filament.

Influence of SiC and ZnO Doping on the Electrical Performance of Polylactic Acid-Based Triboelectric Nanogenerators.

Polylactic acid (PLA) is one of the most widely used materials for fused deposition modeling (FDM) 3D printing. It is a biodegradable thermoplastic polyester, derived from natural resources such as corn starch or sugarcane, with low environmental impact and good mechanical properties. One important feature of PLA is that its properties can be modulated by the inclusion of nanofillers. In this work, we investigate the influence of SiC and ZnO doping of PLA on the triboelectric performance of PLA-based tribogenerators. Our results show that the triboelectric signal in ZnO-doped PLA composites increases as the concentration of ZnO in PLA increases, with an enhancement in the output power of 741% when the ZnO concentration in PLA is 3 wt%. SiC-doped PLA behaves in a different manner. Initially the triboelectric signal increases, reaching a peak value with enhanced output power by 284% compared to undoped PLA, when the concentration of SiC in PLA is 1.5 wt%. As the concentration increases to 3 wt%, the triboelectric signal reduces significantly and is comparable to or less than that of the undoped PLA. Our results are consistent with recent data for PVDF doped with silicon carbide nanoparticles and are attributed to the reduction in the contact area between the triboelectric surfaces.

Composite PCL Scaffold With 70% β-TCP as Suitable Structure for Bone Replacement

The purpose of this work was to optimise printable polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP) biomaterials with high percentages of β-TCP endowed with balanced mechanical characteristics to resemble human cancellous bone, presumably improving osteogenesis. PCL/β-TCP scaffolds were obtained from customised filaments for fused deposition modelling (FDM) 3D printing with increasing amounts of β-TCP. Samples mechanical features, surface topography and wettability were evaluated as well as cytocompatibility assays, cell adhesion and differentiation. The parameters of the newly fabricated materila were optimal for PCL/β-TCP scaffold fabrication. Composite surfaces showed higher hydrophilicity compared with the controls, and their surface roughness sharply was higher, possibly due to the presence of β-TCP. The Young's modulus of the composites was significantly higher than that of pristine PCL, indicating that the intrinsic strength of β-TCP is beneficial for enhancing the elastic modulus of the composite biomaterials. All novel composite biomaterials supported greater cellular growth and stronger osteoblastic differentiation compared with the PCL control. This project highlights the possibility to fabricat, through an FDM solvent-free approach, PCL/β-TCP scaffolds of up to 70 % concentrations of β-TCP. overcoming the current lmit of 60 % stated in the literature. The combination of 3D printing and customised biomaterials allowed production of highly personalised scaffolds with optimal mechanical and biological features resembling the natural structure and the composition of bone. This underlines the promise of such structures for innovative approaches for bone and periodontal regeneration.

Fused Deposition Modeling of Isotactic Polypropylene/Graphene Nanoplatelets Composites: Achieving Enhanced Thermal Conductivity through Filler Orientation.

High-performance thermally conductive composites are increasingly vital due to the accelerated advancements in communication and electronics, driving the demand for efficient thermal management in electronic packaging, light-emitting diodes (LEDs), and energy storage applications. Controlling the orderly arrangement of fillers within a polymer matrix is acknowledged as an essential strategy for developing thermal conductive composites. In this study, isotactic polypropylene/GNP (iPP/GNP) composite filament tailored for fused deposition modeling (FDM) was achieved by combining ball milling with melt extrusion processing. The rheological properties of the composites were thoroughly studied. The shear field and pressure field distributions during the FDM extrusion process were simulated and examined using Polyflow, focusing on the influence of the 3D printing processing flow field on the orientation of GNP within the iPP matrix. Exploiting the unique capabilities of FDM and through strategic printing path design, thermally conductive composites with GNPs oriented in the through-plane direction were 3D printed. At a GNP content of 5 wt%, the as-printed sample demonstrated a thermal conductivity of 0.64 W/m · K, which was 1.5 times the in-plane thermal conductivity for 0.42 W/m · K and triple pure iPP for 0.22 W/m · K. Effective medium theory (EMT) model fitting results indicated a significantly reduced interface thermal resistance in the through-plane direction compared to the in-plane direction. This work shed brilliant light on developing PP-based thermal conductive composites with arbitrarily-customized structures.

Development of 3D Printing Filaments from Recycled PLA Reinforced with Nanoclay

This study focused on the development of 3D printing filaments suitable for fused deposition modeling (FDM) by recycling expired polylactic acid (PLA) filaments. The 3D printing filaments were processed into pellets by incorporating montmorillonite (MMT) nanoclay into the expired PLA filaments through twin-screw extrusion with varying concentrations of 1%, 3%, and 5 wt.%. These composite pellets were reprocessed to filaments through a filament extruder with a diameter of 1.75 mm. These filaments underwent different characterization techniques to test its mechanical and thermal properties. The thermal properties showed increasing values in the glass transition temperature, crystallization temperature, and melting temperature with a decrease in the specific heat upon incorporating increasing amount of MMT nanoclay. Furthermore, thermogravimetric analysis (TGA) showed a positive impact with better thermal stability when the MMT content was incorporated. In terms of mechanical properties, the study showed that the addition of 1 wt% MMT nanoclay, provided an increase in both the tensile strength and elastic modulus comparable to the virgin 3D printing PLA filament.

Effect of Nano-Alumina (Al<sub>2</sub>O<sub>3</sub>) Loading on the Thermo-Mechanical Properties of Poly(Lactic Acid) for Fused Deposition Modeling 3D Printing Applications

This research focused on the development of filament composite materials for fused deposition modeling (FDM) 3D printing applications. The main objective of this study was to fabricate and characterize poly (lactic acid) (PLA) filaments with varying amounts of alumina (Al2O3) nanopowder (0, 2.5, 5.0, and 10.0 wt.%). The resulting PLA/Al2O3 filament blends were produced using hot-melt extrusion. The filament blends were subjected to different characterization techniques and mechanical testing. The results indicate that the thermal stability of the filaments increased with increasing filler content. Furthermore, PLA with 5.0 wt.% nanoAl2O3 exhibited 55.84%, 66.14%, and 45.84% improvement in tensile strength, elastic modulus, and toughness, respectively.

Polyvinyl Alcohol, a Versatile Excipient for Pharmaceutical 3D Printing.

Three-dimensional (3D) printing in the pharmaceutical field allows rapid manufacturing of a diverse range of pharmaceutical dosage forms, including personalized items. The application of this technology in dosage form manufacturing requires the judicious selection of excipients because the selected materials must be appropriate to the working principle of each technique. Most techniques rely on the use of polymers as the main material. Among the pharmaceutically approved polymers, polyvinyl alcohol (PVA) is one of the most used, especially for fused deposition modeling (FDM) technology. This review summarizes the physical and chemical properties of pharmaceutical-grade PVA and its applications in the manufacturing of dosage forms, with a particular focus on those fabricated through FDM. The work provides evidence on the diversity of dosage forms created using this polymer, highlighting how formulation and processing difficulties may be overcome to get the dosage forms with a suitable design and release profile.

Direct ink writing of polymer matrix composite with carbon for driving a flexible thermoelectric actuator of shape memory polymer

Carbon nanomaterials and polymer composites that possess excellent electrical and mechanical properties for soft robots have been investigated over decades in multidisciplinary research fields. As considering the incorporation of carbon into polymer composite, several major concerns include the electrical conductivity, elastic module, and manufacturing flexibility that can enable them to satisfy various functions such as actuation and sensing. In this paper, we report a comprehensive study on how to design and fabricate a soft gripper based on carbon polymer matrix composite and multilayer structure through multistep processes of 3D printing on paper. Using commercial conductive additives of graphene and carbon nanotube with polydimethylsiloxane (PDMS), a polymer matrix composite (PMC) was prepared for the ink of direct ink writing (DIW) with percolation conductivity. Additionally, a shape memory polymer (SMP) was utilized for fused deposition modeling (FDM) of a thermal actuator. Incorporating the DIW of PMC with the FDM of SMP on paper, a soft gripper with four fingers was designed and fabricated to show remarkable thermoelectrical actuation for grasping a 50 mm-diameter 10 g-weight spherical ball. In the future, it would provide an alternative approach for the fields of science and engineering, such as nanomaterials and nanotechnology, space applications, sustainable soft robots, and flexible autonomous systems.

Customizable Three-Dimensional Printed Earring Tap for Treating Affections Caused by Aesthetic Perforations.

This work aimed to develop a three-dimensional (3D) wearable drug-loaded earring tap to treat affections caused by aesthetic perforations. The initial phase involved a combination of polymers to prepare filaments for fused deposition modeling (FDM) 3D printing using a centroid mixture design. Optimized filament compositions were used in the second phase to produce 3D printed earring taps containing the anti-inflammatory naringenin. Next, samples were assessed via physicochemical assays followed by in vitro skin permeation studies with porcine ear skin. Two filament compositions were selected for the study's second phase: one to accelerate drug release and another with slow drug dissolution. Both filaments demonstrated chemical compatibility and amorphous behavior. The use of the polymer blend to enhance printability has been confirmed by rheological analysis. The 3D devices facilitated naringenin skin penetration, improving drug recovery from the skin's most superficial layer (3D device A) or inner layers (3D device B). Furthermore, the devices significantly decreased transdermal drug delivery compared to the control containing the free drug. Thus, the resulting systems are promising for producing 3D printed earring taps with topical drug delivery and reinforcing the feasibility of patient-centered drug administration through wearable devices.

Comparative study of evolutionary machine learning approaches to simulate the rheological characteristics of polybutylene succinate (PBS) utilized for fused deposition modeling (FDM)

Comparative study of evolutionary machine learning approaches to simulate the rheological characteristics of polybutylene succinate (PBS) utilized for fused deposition modeling (FDM)

3D printing of MAX/PLA filament: Electrochemical in-situ etching for enhanced energy conversion and storage

Two-dimensional (2D) MXenes are promising materials for a variety of sustainable energy-related applications such as photoelectrochemical water splitting and energy storage devices. Among the MXene family, the Ti3C2Tx is mostly prepared by selective etching of Al from the Ti3AlC2 MAX phase using hydrofluoric acid (HF) or in-situ produced HF as an etchant. However, the severe toxicity, handling of HF acid as well as the oxidation and degradation of freshly synthesized MXenes when stored as aqueous suspensions obstruct the large-scale production of MXenes. 3D printing is an innovative and versatile technology utilized for a plethora of applications in the field of energy applications. Thus, integration of 3D printing technology with the synthesis procedure of MXene will provide a new outlook for large-scale production and the long-storing capability of MXene. Herein, we fabricated a novel MAX (Ti3AlC2)/polylactic acid (PLA) filament for fused deposition modeling (FDM) 3D printing followed by etching of the 3D-printed MAX/PLA electrode into 3DP-etched-MAX employing chronoamperometry technique consecutively in 9 M HCl and 4 M NaOH as electrolytes. The 3D printed electrochemically etched MAX (3DP-etched-MAX) electrode shows promising behaviour for the photoelectrochemical hydrogen evolution reaction (HER) and capacitive performance. In general, this work demonstrates a path of production of large-scale manufacturing of MAX/PLA filament and 3DP-etched-MAX electrodes without using toxic HF for energy conversion and energy storage applications. This work paves the way to fabricate other novel MAX filaments and electrodes for several applications beyond energy conversion and storage.

A Biologically Degradable and BioseniaticTM Feedstock for the High-Quality 3D Printing of Anatomical Models.

A Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) -based filament was evaluated as an alternative feedstock for Fused Deposition Modeling (FDM) of instructional and clinical medical specimens. PHBHHx-based prints of domestic cat vertebrae, skull bone, and an aortic arch cast were found comparable to conventional materials. PHBHHx-based filament and extrudate samples were evaluated for biological degradability, to meet the BioseniaticTM standard, defined by the University of Georgia New Materials Institute. Both samples achieved more than 90% mineralization within 32 days in industrial composting conditions.

Study on Recyclebot with 3D Printing Wastes for Circular Economy

Plastic is widely used today. Plastic-made items and components have limited lifespans and are quickly disposed of in landfills. Finding new pathways for plastic waste recycling has become a critical focus of sustainability efforts, especially within additive manufacturing (AM) . This paper evaluates the feasibility of producing filaments from the waste plastics using recyclebot for fused deposition modeling (FDM), a widely used AM technique. An indigenous recyclebot was designed and developed. Trial studies have been carried out using ABS (Acrylonitrile Butadiene Styrene) pellets. Dimensional quality tests were performed on the extruded filaments. Effects of moisture content on the dimensional quality are evaluated. Additionally, the filaments exhibited good flexibility and consistent density. This study establishes that by incorporating recyclebots with existing FDM techniques will significantly reduce the plastic waste within manufacturing and can easily incorporate with circular economy model.

Mechanical and tribological properties of FDM-printed polyamide

As one of the most important raw materials for fused deposition modeling (FDM) 3D printing, polyamide (PA) is widely used in many fields because of its excellent properties. For PA FDM, the parameters are highly important to the performance of the printed parts without doubt. Herein, the effect of two main printing parameters (nozzle temperature and layer thickness) on the mechanical properties and tribological properties of FDM-printed PA were investigated. Results show that the mechanical properties of PA increase yet the wear rate reduces with the increase of nozzle temperature from 240 °C to 260 °C, while the friction coefficient (COF) shows few variation. With the increase of layer thickness from 0.1 mm to 0.3 mm, the mechanical properties decline, while the COF increases. Surprisingly, polishing of the 3D printed PA increases the COF to the range of 0.40 to 0.60 from about 0.05 of unpolished, which is attributed to the disappearance of the smooth and hard surface layer caused by extrusion after polishing. For demonstrate, planetary gears were manufactured with the optimized parameters of nozzle temperature of 260 ℃ and layer thickness of 0.1 mm, found running stably at 200 rpm/min without any noise.

Synergistic effect of CaCO3 addition and cold atmospheric plasma treatment on the surface evolution, mechanical properties, and in-vitro degradation behavior of FDM-printed PLA scaffolds

The ease of processing and biocompatibility of polylactic acid (PLA) have made it a widely used material for fused deposition modeling (FDM)-based 3D printing. In spite of this, PLA suffers from some limitations for its extensive use in tissue engineering applications, including poor wettability, low degradation rate, and insufficient mechanical properties. To address the previously mentioned limitations, this study examined how combining in-process cold atmospheric plasma treatment with the inclusion of CaCO3 influences the properties of FDM-printed PLA scaffolds. Differential scanning calorimetry results showed that by incorporating CaCO3 micro-particles into the PLA matrix, heterogeneous nucleation promoted the matrix's crystalline content. Scanning electron microscopy analysis revealed that the surface of the PLA-CaCO3 scaffold exhibited increased roughness and improved interlayer bonding after undergoing plasma treatment. Atomic force microscopy revealed a significant (up to 80-fold) increase in the roughness value of PLA scaffolds after the incorporation of CaCO3 and subsequent cold plasma treatment. Furthermore, X-ray photoelectron spectroscopy analysis indicated that atmospheric plasma treatment substantially increased the presence of oxygen-containing bonds, leading to a significant reduction in the water contact angle, which decreased from 89° to 37°. According to the tensile test, the tensile modulus (634.1 MPa) and ultimate tensile strength (25.4 MPa) of PLA were markedly increased and reached 914.3 and 37.2 MPa, respectively, for the plasma-treated PLA-CaCO3 (PT-PLA-CaCO3). Additionally, the in-vitro degradation test showed that PT-PLA-CaCO3 scaffold exhibited higher degradation rate compared to the PLA-CaCO3 sample. Based on the obtained results, it appears that in-process cold atmospheric plasma treatment could serve as an efficient and straightforward method to enhance the properties of 3D-printed composite parts, particularly for tissue engineering applications.

Investigation of micro lattice spiral wound membrane structures availing DLP and FDM techniques for water treatment

This study addressed the challenge of reducing water contaminants using Spiral Wound Membrane (SWM) units in desalination and water treatment. Through additive manufacturing, we developed complex micro-lattice feed-spacer structures using FlexBLK 20, Pro-BLK10, ToughBLK 20, PLA, PETG, and ABS materials. The AHPTOPSIS statistical method indicated an ideal solution with Digital Light Processing (DLP) conditions showing a 20 μm layer thickness, FlexBLK-20 material, diamond structure, and for Fused Deposition Modeling (FDM) conditions, a 0.1 mm layer thickness, PLA material, and gyroid structure. Significant findings include a decrease in surface roughness by 79.67%–85.25% for DLP, an elongation increase of 50%–91.67%, and tensile strength improvement between 0.07%–40.83%. DLP printed feed spacers showcased better surface distributions than FDM, attributed to finer layers and higher density printing. Additionally, DLP printing resulted in a 32.02% increase in residual stress, suggesting superior compressive resistance. In thermal analyses, both DLP and FDM materials showed thermal stability up to 380 °C–450 °C. This research indicates that DLP printed feed spacers, with their enhanced properties, are potentially more efficient for water purification systems, providing smoother surface, better filtration, and increased durability.

On 3D printed polyvinylidene fluoride-based smart energy storage devices

Polyvinylidene fluoride (PVDF) is one of the established thermoplastics with inherent piezoelectric characteristics. In the past two decades, a lot of work has been reported on the use of virgin Polyvinylidene fluoride thermoplastics for sensing applications. But hitherto little has been reported on 3D printing of secondary (2°) recycled Polyvinylidene fluoride as a smart energy storage device (ESD). This work is focused on exploring the possibilities for 3D printing of smart energy storage device comprising of Polyvinylidene fluoride having (melt flow index (MFI) 30 g/(10 min) as per ASTM D 1238) reinforced with MnO2, graphite, ZnCl2, and N [Formula: see text] Cl in different weight proportions to form a feedstock filament for fused deposition modeling (FDM) in the first stage. The MFI of Polyvinylidene fluoride composites reinforced with MnO2, graphite, ZnCl2, and N [Formula: see text] Cl (34.095, 8.480, 42.982, 11.807 g/(10 min) respectively) was ascertained for possible 3D printing on FDM. The results suggest that even with an acceptable MFI of prepared 2° recycled Polyvinylidene fluoride, the same was not printable. Further for possible 3D printing on FDM, low-density polyethylene (LDPE) was blended in a Polyvinylidene fluoride matrix, and successful 3D printing-based energy storage device was prepared in the second stage. The study also highlights the mechanical, and morphological properties of Polyvinylidene fluoride composites have been improved after processing with a twin-screw extruder (TSE) by using different input parameters (screw temperature (T), screw speed (S), and load (L)). Overall, the study suggests that the proportion of LDPE, MnO2, graphite, ZnCl2, and N [Formula: see text] Cl has a significant effect on the rheological, mechanical, and morphological properties. The results have been supported with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Fourier-transformed infrared spectroscopy (FTIR) analysis.