Fused Deposition Modeling Research Articles

Influence of Printing Parameters to optimize mechanical properties in additive manufacturing – A Review

Abstract Additive manufacturing (3D printing) is a revolutionary technology with widespread applications among various industries. It is a cost effective and fast prototyping technology of 20th century, the parts produced by 3D printing are not only used for pre-production samples but also for replacement of functional parts in various applications. Various methods of 3D printing technologies viz., Fused Deposition, Resin printing etc., are available, however Fused Deposition Modelling (FDM) technique is very popular since it is promising and cost effective. There are two major aspects needs to be considered in preparing a sample from 3D printing, i.e., selection of material and printing parameter. With the advancement of material technology from time to time, the efficient and quality products that are produced with this technology. The present study explores the impact of various parameters that affect mechanical properties of 3D printed Polylactic Acid (PLA) in horizontal orientation.

Melting and solution mixing in the production of photocatalytic filaments for 3D printing

3D printing is a fast-growing technology with benefits like rapid prototyping and versatile design capabilities. However, Fused Deposition Modeling (FDM) needs improvement due to limited material options. This study proposes a method for producing photocatalytic prototypes using 3D printing/FDM, focusing on environmental applications like contaminant degradation. Key steps included filament production through melt and solution mixing, defining geometries, 3D printing functional prototypes, and characterizing materials chemically, thermally, microscopically, and mechanically. The photocatalytic capacity was evaluated via tetracycline degradation, showing 45–60% efficiency for ZnO filaments and up to 65% for TiO2 filaments. ZnO-functionalized parts maintained 80% removal capacity after 10 reuse cycles without activation, indicating reduced leaching and photo corrosion. This study advances 3D printing/FDM research for environmental applications, providing a methodology for producing effective photocatalytic prototypes.

The development and characterisation of 3D-printed multi-material thermistor

This paper introduces a multi-material, low-cost, and highly sensitive thermistor concept developed for body temperature monitoring. The designed thermistor employs poly(3,4-ethylenedioxythophene):poly(4-styrenesulfonate) (PEDOT:PSS) for the temperature sensing layer, silver (Ag) for the contact electrodes, and polycarbonate (PC) as the substrate. In contrast to traditional printed electronics substrates used in thermistor development, the utilisation of Material Extrusion via Fused Deposition Modelling (FDM) for the manufacture of PC substrates is the distinct feature of the work. For the manufacture of multi-material thermistors two different Additive Manufacturing (AM) methods: FDM for substrates and micro dispensing for PEDOT:PSS sensing layer and Ag electrodes, were utilised. Two thermistors with varying sensing areas, namely D1 and D2, were designed and fabricated. The thermistors demonstrated a high degree of linearity and repeatability within the temperature range of 25–45°C with a viable hysteresis maximum around 3%. The measurement sensitivity of thermistors was assessed based on Temperature Coefficient of Resistance (TCR) values, which were –0.68 ±0.057% and –0.49 ±0.078% per °C for the D1 design and –0.53 ±0.078% and –0.40 ±0.069% per °C for the D2 design, during heating and cooling, respectively. Comparable average response and recovery times to the literature were also acquired, which were 31.47 ±1.02 and 54.42 ±0.70seconds for D1 and 27.38 ±0.96 and 48.45 ±1.69seconds for D2, during heating and cooling, respectively. It was evident that the sensing area had an impact on thermistor TCR as well as response and recovery times, where higher TCR and faster response and recovery times were recorded with the small sensing area. It was also observed that humidity had a significant impact on thermistor reliability, exhibiting a normalised resistance change of ∼12% and ∼9% of the initial measurement at 50 and 75% RH, respectively. When compared to PEDOT:PSS-based thermistors reported in the literature, the obtained results in this research have demonstrated that our multi-material thermistor concept is a promising candidate for the low-cost and highly sensitive multi-material thermistor that can be manufactured in a fully additive manner using AM technologies.

Investigating the mechanical properties and crashworthiness of hybrid PLA/GFRP composites fabricated using FDM-filament winding

The failure and crashworthiness performance of hybrid Polylactide (PLA)/Glass Fiber Reinforced Polymer (GFRP) composite tubes subjected to axial and radial quasistatic compression loads were investigated in the present study. The composite tubes are fabricated using hand lay-up and Fused Deposition Modeling (FDM)-filament winding processes. The crashworthiness performance was studied using parameters such as the peak load, energy absorption, crush load, crushing load efficiency, and specific energy absorption. The highest peak loads from the compression test results in the axial and radial directions are calculated using variations in the filament winding PLA/GFRP (FPG) specimen, whose values were 16130.50 N and 12077.33 N, respectively. The highest mean crush load is found in the material variation with the FPG specimen, which is 5734.43 J/mm for axial loading and 4886.75 J/mm for radial loading. The highest energy absorption (EA) value is found in the material variation with the FPG specimen, which is 262.18 J for axial direction loading and 94.02 J for radial direction loading. The highest specific energy absorption (SEA) value is found in the material variation with the specimen Filament Winding PLA/GFRP, which is 16.92 J/g for axial loading and 10.98 J/g for radial loading. There are three main types of failure of the composite: matrix cracking, fiber damage, and folding. The study showed that by combining Additive Manufacturing and composite lamination, the hybrid PLA/GFRP specimen outperformed the existing structures.

Structural integrity of polymers processed by additive manufacturing techniques using residual strength diagrams

Motivated by the increasingly important role that polymers have in structural applications, this study aims to analyse the structural integrity of polymers through residual strength diagrams. The polymers analysed have been thermoplastics, Polylactic acid (PLA), Polyethylene terephthalate glycol-modified (PET-G) and Polyamide 12 (PA-12), as well as a thermosetting resin, processed through different additive manufacturing techniques: Fused Deposition Modelling (FDM) in the case of PLA, PET-G, Selective Laser Sintering (SLS) for PA-12 and Digital Light Processing (DLP) for the thermosetting resin. In addition, PA-12 manufactured by injection moulding was also included in this study. To obtain the residual strength diagrams, mechanical tests have been carried out on smooth specimens and on specimens with cracks of different lengths. From the analysis of the results, a prediction has been obtained by fitting a semi-empirical model that describes the structural integrity in the areas of microstructurally short cracks, long cracks and physically short cracks.

Direct Ink Writing 3D Printing Elastomeric Polyurethane Aided by Cellulose Nanofibrils.

3D printing of a flexible polyurethane elastomer is highly demandable for its potential to revolutionize industries ranging from footwear to soft robotics thanks to its exceptional design flexibility and elasticity performance. Nevertheless, conventional methods like fused deposition modeling (FDM) and vat photopolymerization (VPP) polyurethane 3D printing typically limit material options to thermoplastic or photocurable polyurethanes. In this research, a water-borne polyurethane ink was synthesized for direct ink writing (DIW) 3D printing through the incorporation of cellulose nanofibrils (CNFs), enabling direct printing of complex, monolithic elastomeric structures at room temperature that can maintain the designed structure. Additionally, a solvent-induced fast solidification (SIFS) method was introduced to facilitate room-temperature curing and enhance mechanical properties. The 3D-printed WPU structures demonstrated strong interfacial adhesion, exhibiting high ultimate tensile strength of up to 22 MPa and an elongation at break of 951%. The 3D-printed WPU structures also demonstrated outstanding resilience and durability, capable of enduring more than 100 cycles of compression and tension as well as withstanding vehicle crushing and heavy lifting. This method also shows suitability for 3D printing complex structures such as a vase and an octopus.

An experimental analysis of mechanical properties for a dissimilar pattern structure in the 3-D printing of a PLA5F filament using the Taguchi method

Abstract Many automobile components and machine parts can be fabricated using the Fused Deposition Modeling (FDM) process with materials such as Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate Glycol (PET-G), and polymeric composite materials (e.g., PLA with carbon fiber, PLA with glass fiber). In this study, a new polymeric composite material was fabricated using Polylactic Acid and natural flax fiber was analysed for tensile stress, elongation, and impact load resistance using Taguchi Analysis. This analysis optimized the printing parameters, including layer thickness (0.15, 0.25, 0.35 mm), nozzle movement speed (80, 100, 120 mm s−1), filling structure (Lines - a, Triangular - b, and Octet - c), and occupancy rate (20%, 40%, 60%). The American Society for Testing and Materials (ASTM) standards for tensile strength (ASTM D638) and impact strength (ASTM D256) were used for evaluation. As a result, layer thickness was found to be the most effective variable for improving tensile characteristics, compared to extruder temperature, occupancy rate, or filling structure pattern. Mechanical properties including a layer thickness of 0.25 mm, an occupancy ratio of 20% for the bottom of the 2nd layer and 40% for the top of the 4th layer, triangular and octet filling structures, a nozzle speed of 100 mm s−1, and an extruder temperature of 200 °C are considered the most appropriate parameters for producing automotive parts in Three Dimensional (3D) Printing. Due to its tensile properties and impact strength resistance, these settings can be utilized in potential application in a wide variety of machine parts and vehicle components.

A human-centered intelligent platform for holographic control and management of 3D printers

Under the wave of emerging human-centric concepts such as Industry 5.0 and Human-Centered Intelligent Manufacturing, Mixed Reality (MR) has emerged as a pivotal enabling technology with profound impacts on human–machine interaction. Simultaneously, the affordability of Fused Deposition Modeling (FDM) 3D printers has expanded their accessibility beyond industrial applications to homes and public spaces. However, the operational and management complexities of different 3D printers and their varying human–machine interfaces (HMI) present challenges for users, especially beginners. In this paper, we presented a human-centered intelligent platform for FDM 3D printer control and management enabled by Mixed Reality. A flexible system architecture is developed in the paper with two essential communication protocols, MQTT and WebSocket, for stable data transfer. In addition, a task-oriented HMI is explored on the MR headset to simplify the operation procedure with little training effort and allow parallel supervision of multiple machines. By leveraging the advantages of our architecture, real-time monitoring, failure detection, and hologram visualization were able to be integrated into our platform for intelligent operation and management. Importantly, the flexibility of the architecture via a holographic interface enables our platform to easily expand to various machining operations in the future.

Circulation process of methyl ester production from pretreated sludge palm oil using CaO/ABS catalytic static mixer coupled with an ultrasonic clamp

This study investigates the potential of fused deposition modeling (FDM) three-dimensional (3D) printing techniques for manufacturing catalytic static mixers during biodiesel synthesis. The printed catalytic mixing elements comprises acrylonitrile butadiene styrene (ABS) plastic with 15 wt% calcium oxide (CaO) as a solid catalyst. When the reactants flowed through the CaO/ABS mixing device, the blending and acceleration processes were both significantly impacted. Moreover, their characteristics, performance in biodiesel production, reusability, and economy were analyzed. The effects of methanol to oil (M:O) molar ratio, circulation time, and sonication time on methyl ester (ME) purity were also examined. The results showed that CaO crystals were distributed on the CaO/ABS mixer’s surface, which is crucial for catalytic purposes. During circulation process of ME from pretreated sludge palm oil (PSPO), catalytic static mixer (CSM) and CSM coupled with ultrasound (CSM/US) reactors were employed. The full ultrasonic power of CSM/US reactor of 16 × 400 W (total 6400 W) was operated at 20 kHz frequency. Moreover, the continuous and pulse ultrasonic modes of CSM/US reactor were compared to determine the ME purity and electricity consumption for ME production. For the CSM reactor, 12:1 M:O molar ratio and 8.5 h circulation time were recommended to realize 94.2 wt% ME purity. For the CSM/US reactor, 12:1 M:O molar ratio and 2.25 h circulation time were recommended to achieve 96.5 wt% ME purity. Under the pulsed mode operation, ME purity of 95.09 wt% was achieved, with a reduction in electricity consumption by approximately 37.6 % compared to continuous mode operation. Furthermore, the CaO/ABS catalytic static mixer was determined to be reusable for up to three cycles in both CSM and CSM/US reactors. Thus, CaO/ABS catalytic static mixers assure high purity ME production through FDM 3D printing technology with a CaO solid catalyst.

Functional Silsesquioxanes-Tailoring Hydrophobicity and Anti-Ice Properties of Polylactide in 3D Printing Applications.

To explore the tailoring of hydrophobicity in 3D-printed polylactide (PLA) composites for advanced applications using additive manufacturing (AM), this study focuses on the use of Fused Deposition Modeling (FDM) 3D printing. PLA, a material derived from renewable sources, is favored for its eco-friendliness and user accessibility. Nonetheless, PLA's inherent hydrophilic properties result in moisture absorption, negatively affecting its performance. This research aims to modify PLA with organosilicon compounds to enhance its hydrophobic and anti-icing properties. Incorporating fluorinated siloxane derivatives led to significant increases in water contact angles by up to 39%, signifying successful hydrophobic modification. Mechanical testing demonstrated that the addition of organosilicon additives did not compromise the tensile strength of PLA and, in some instances, improved impact resistance, especially with the use of OSS-4OFP:2HEX:2TMOS, which resulted in an increase in the tensile strength value of 25% and increased impact strength by 20% compared to neat PLA. Differential scanning calorimetry (DSC) analysis indicated that the modified PLA exhibited reduced cold crystallization temperatures without altering the glass transition or melting temperatures. These results suggest that organosilicon-modified PLA has the potential to expand the material's application in producing moisture and ice-resistant 3D-printed prototypes for various industrial uses, thereby facilitating the creation of more durable and versatile 3D-printed components.

Stereolithography-assisted sodium alginate-collagen hydrogel scaffold with molded internal channels

Fabricating internal vascular networks within a hydrogel scaffold is essential for facilitating the supply of nutrients, oxygen, and metabolism exchange required by the encapsulated cells. The challenges in current hydrogel scaffold fabrication involve the difficulty of building adequate internal channels, poor scaffold geometry precision, and low cell viability caused by the fabrication process and polymer material properties. Stereolithography (SLA) stands out as a 3D printing technique distinguished by its superior production efficiency, advanced precision, and remarkable resolution in crafting intricate custom geometries. These attributes establish it as an innovative approach for templates in scaffold fabrication, potentially surpassing the fused deposition modeling (FDM)-based template strategy. Meanwhile, it exerts less shear stress on the cells compared to the direct bioprinting process. This novel strategy enables the fabrication of hydrogel vascular structure within the precision of 500 µm in both channel diameter and wall thickness. In this paper, various sodium alginate and collagen (SA-Col) composite hydrogels with varying collagen concentrations have been investigated to identify the optimal ratio for fabricating hydrogel scaffolds with channels.

Real-time monitoring of the spatiotemporal thermal state of fused filament fabrication process for shape memory polymers

This study investigates a multi-sensor approach to estimate the surface thermal fields of Fused Filament Fabrication (FFF), an additive manufacturing process, at high spatial (4 μm) and temporal (0.1 msec) resolutions. The current state-of-the-art methods for quantifying the thermal, mechanical, and chemical state of the FFF processes are categorized into two main groups: numerical simulations and in-process thermal monitoring. Although numerical simulations can precisely estimate the process state for simple components, they are computationally demanding, become less accurate when complexity increases, and are therefore not suitable for real-time monitoring. In-process thermal monitoring, on the other hand, is becoming vital to track the process’ state, and offers a means to discern the underlying phenomena. While the current thermal sensors offer sub-mm scale spatial resolutions, their temporal resolutions (at best 1 msec) do not allow tracking of the thermal gradients necessary to determine the build geometry, microstructure, and the properties of the components. They are also limited by the cost and size, and need custom fixtures for mounting to a printer. The study proposes an approach based on pairing a primary high-tech thermal sensor with a secondary small footprint vibration sensor using a machine learning model to reconstruct the thermal fields at high time-resolutions from vibration signals. The key steps of this novel ML pipeline consisted of a singular value decomposition (SVD) of the ground truth of the thermal images and a time–frequency transformation with fast Fourier of the vibration signal. The overall model was able to make inferences and predict with 91.36 % accuracy the thermal state of the process using only vibration data as input. In addition, the ML pipeline filtered part of the experimental error contained in the ground truth data.

Study on the refrigeration performance of a miniature pulse tube cryocooler driven by a gas bearing compressor

Recent advancements in long-term space exploration, maintenance-free miniature-satellites and drone infrared detections have created a large demand for highly reliable and miniaturized cryocoolers working at 77–150 K. The pulse tube cryocooler (PTC) has no moving part at the cold end, and if driven by a gas bearing linear compressor which has no mechanical fatigue risk, a refrigeration system with high reliability and compactness will be generated. However, very few researches on the cooling performance of PTC driven by gas bearing linear compressor have been reported. In this study, a miniature PTC and gas bearing compressor are developed, with a weight of the whole refrigeration system about 0.97 kg. The maximum cooling capacity reaches 1.73 W at 77 K with input electric power of 66 W. The cooling capacity per unit weight for this cryocooler is 1.78 W/kg at 77 K, which is the highest compared to those of the existing typical miniature cryocoolers, showing its remarkable lower mass for refrigeration. In addition, the influence of the hot end heat dissipation temperature on the cooling performance is studied. It is found that the heat dissipation temperature of the hot end has a significant effect on the cooling performance. For every 10 K decrease in the hot end temperature, the maximum cooling capacity at 77 K increases by 3.45 % to 13.28 %, the relative Carnot efficiency rises by 4.38 % to 12.59 %. Besides, in the miniature PTC, the cooling performance is very sensitive to the length of the inertance tube, even a small change of 10–20 mm on the length of the inertance tube will lead to obvious effect on the optimum frequency and cooling performance of the system. These results will be helpful for the further research and development of the miniature pulse tube cryocoolers.

Analysis of Metal Fused Filament Fabrication process chain for 316L stainless steel

Metal Fused Filament Fabrication (MFFF) has emerged as a prominent technology in Additive Manufacturing (AM), characterized by its cost-effectiveness, versatility in creating intricate geometries using diverse materials, and widespread availability of AM machines. However, the intricate processes of making filament, printing, debinding, and sintering in MFFF pose unique challenges, with a vast number of parameters influencing each stage. Specialized companies handle these stages for research purposes, yet detailed information on the processes remains limited. The objective of this research is to conduct a meticulous examination of the parameters governing the printing, debinding, and sintering of 316L stainless steel—a material widely employed in various industries. The goal is to provide researchers and manufacturers with a comprehensive understanding, enabling them to achieve high-density metal parts that rival those produced through Selective Laser Melting (SLM). This research employs a systematic approach in producing flawless metal parts through fine-tuning parameters such as printing speed, nozzle diameter, extruder and construction table temperatures, heating rate, nitric acid injection during debinding, and sintering atmosphere and temperature. Despite advancements in MFFF parameters in this study, a comparative analysis with SLM reveals superior mechanical properties and density in SLM-produced parts. Because, the robust bonding facilitated by a powerful energy source (laser) in SLM minimizes porosities, whereas MFFF relies solely on molten filament adherence, potentially leading to small gaps between layers. This research contributes valuable insights for achieving dense, defect-free metal parts through Metal Fused Filament Fabrication (MFFF). It sheds light on the persistent advantages of Selective Laser Melting (SLM) in terms of mechanical performance and density. The comprehensive understanding of parameters provided in this study empowers researchers and manufacturers to optimize MFFF processes for 316L stainless steel, narrowing the gap between the two technologies (MFFF and SLM) and enhancing the competitiveness of MFFF in producing high-quality metal parts.

Quantum machine learning for additive manufacturing process monitoring

Machine learning is useful for analyzing and monitoring complex manufacturing processes. However, it has several limitations including the curse-of-dimensionality and lack of training data. In this paper, we propose a quantum machine learning strategy to tackle these challenges. Quantum support vector machine is applied to identify the states of machines in fused filament fabrication process based on acoustic emission data. Quantum convolutional neural network is used to detect spatters in laser powder bed fusion process based on coaxial optical images. Our results show that quantum machine learning can achieve the similar accuracy levels of predictions by classical machine learning counterparts, but with exponentially fewer parameters.

A 3D printing-based hybrid manufacturing method for high-strength polymeric medical implant fabrication

This paper presents a novel 3D printing-based hybrid manufacturing method to fabricate high-strength polymeric medical implants. Poly-ether-ether-ketone (PEEK) and polyether sulfone (PES) are blended to make filament for use with the fused filament fabrication technique to print custom designed implants. After printing and annealing, PES is removed by leaching to create interconnected porous PEEK structure with suitable pore size and porosity for bone tissue ingrowth. The proposed method provides a versatile approach to fabricating medical implants that are both mechanically strong and microstructurally inducive to osseointegration. The polymeric implants are also X-ray transparent to allow post-surgery evaluations using an imaging method. An intervertebral spacer implant example is used to demonstrate the proposed fabrication method.

3D-printed gradient conductivity and porosity structure for enhanced absorption-dominant electromagnetic interference shielding

The application of 3D printing for the development of electromagnetic interference (EMI) shielding materials is currently constrained by a limited range of material options and design schemes. In this work, we developed conductivity-modulated polylactic acid (PLA)-MXene composite filaments for fused deposition modeling (FDM) 3D printing, demonstrating excellent printability and durability. Utilizing these filaments, we propose a design scheme focused on absorption-dominant EMI shielding materials. Our design features non-conductive PLA with larger pores at the incident surface, transitioning to layers with increasing conductivity and decreasing pore sizes. This gradient structure minimizes reflection by providing impedance matching and enhances absorption by extending the propagation path of EM waves through multiple reflections and scattering within the pores. Additionally, interfacial polarization effects between air, PLA, and MXene nanoflakes strengthen the absorption mechanisms. Both simulation and experimental results confirm that the combined gradient conductivity and pore size structures significantly improve EMI shielding effectiveness (EMI SE) and absorptivity, achieving an EMI SE of 65 dB and an absorptivity of 0.76 in the X-band. Our findings underscore its potential to create adaptable, high-performance EMI shields suitable for complex geometries and reducing secondary interference.

Research on ultra-high temperature sensor and cold end compensation error

Abstract An ultra high temperature sensor and cold end compensation error are proposed. Aiming at the ultra-high temperature and relatively complex harsh environment of spacecraft, a sensor probe structure which can withstand the high temperature of 2500°C is presented in this paper. According to the practical application characteristics of the sensor with high measurement accuracy, the author proposed a high-precision cold end compensation method. Through this compensation technology, the ultra-high temperature sensor maintains high-precision temperature measurement in the full temperature range. The simulation analysis of the sensor structure and temperature test show that the sensor can not only realize temperature measurement at ultra-high temperature, but also control the nonlinear error to 0.6% of the full scale. The accuracy of the whole temperature range is controlled within 0.92% of the full scale, which meets the practical requirements.

Simulation analysis and optimization of thermoelectric refrigeration and air conditioning

Abstract Thermoelectric refrigeration technology is mainly through the Peltier effect to achieve refrigeration, thermoelectric refrigeration air conditioning needs to be combined with a certain air flow rate to realize the separation of cold and heat, and make full use of the cold end to realize the refrigeration function, or else the refrigeration efficiency is seriously affected. Based on the ICEPAK simulation platform of ANSYS, we analyze the influence of structure and parameter settings on the conversion efficiency of thermoelectric refrigeration air conditioning fan under the established boundary conditions, establish the relationship between air flow rate and temperature drop value, and put forward the optimization of the product structure design scheme, and the results of the optimization scheme show that there is a peak in the operating current at a certain heat dissipation efficiency; and lengthening the length of the air ducts through the optimization of the structure can enhance the refrigeration effect of the air conditioner.

Fabrication and evaluation of a CMOS-based energy harvesting chip integrating photovoltaic and thermoelectric energy harvesters

This study explores the development of an energy harvesting chip (EHC) using a complementary metal oxide semiconductor (CMOS) process, addressing the need for efficient micro-scale energy harvesters in modern electronics. The EHC integrates a thermoelectric energy harvester (TEH) and a photovoltaic energy harvester (PEH) to maximize energy conversion efficiency. A key challenge in TEH design is enhancing power output, which is addressed by suspending the cold ends of 41 thermocouples within the TEH structure through post-processing. Experimental methods were employed to assess the performance of the TEH, revealing an output voltage of 21.4 mV and a maximum output power of 9.32 nW under a 3 K temperature difference. The TEH demonstrated a voltage factor of 8.9 mV/(mm2·K) and a power factor of 1.3 nW/(mm2·K2). The PEH was designed with novel patterned p-n junctions, integrating lightly doped n-type regions with interdigitated p-type doping to increase junction density, resulting in high conversion efficiency. The experimental results confirm the effectiveness of the EHC design, showcasing its potential in energy harvesting applications.