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The escalating significance of 3D printing in various industries is underscored by its ability to rapidly and cost-effectively produce distinctive parts. Among the 3D printing methods, fused filament fabrication (FFF) has emerged as a highly productive and cost-effective approach. While extensive efforts have been made to enhance the qualities of FFF products, challenges persist in material availability and quality compared to traditional methods. This study provides a meticulous overview of the FFF process, delving into various 3D printing processes, polymers, and polymer composites. Despite documented efforts to augment mechanical, thermal, and electrical properties, material constraints remain a focal point. Our analysis extends to various PLA/biocomposites, shedding light on achieved improvements and potential applications. Looking forward, the future trend in FFF technology suggests a paradigm shift towards enhanced material diversity and performance. Anticipated applications span beyond traditional use cases, encompassing sustainable manufacturing, medical devices, and eco-friendly construction materials. This comprehensive review not only consolidates the current state of FFF and PLA-biocomposites but also anticipates future trends and potential applications. This research enhances the current knowledge of additive manufacturing and sets a standard for assessing developments in FFF technology by comparing them to previous works. [ABSTRACT FROM AUTHOR]

Currently, there is a notable attraction within the industry towards biocomposites, driven by the increasing fascination with natural fiber-reinforced composites (NFRCs). These NFRCs offer remarkable benefits, including cost-effectiveness, biodegradability, eco-friendliness, and favorable mechanical properties. As a result, the manufacturing processes of natural fiber reinforced polymer (NFRP) composites have garnered attention from both industrial professionals and scientists. The emergence of these eco-friendly materials in the automotive and aerospace industries has sparked interest in understanding their production techniques. However, the machining processes of NFRP composites pose significant challenges due to the complex structure of natural fibers, necessitating thorough studies to address these issues effectively. This research paper presents a comprehensive investigation on surface roughness during the milling process of Alfa/epoxy biocomposites. A set of 100 experimental trials was conducted to test the surface roughness, and analysis of variance (ANOVA) was used to assess the impact of cutting parameters and chemical treatment on surface quality. To develop a predictive model for surface roughness, a hybrid approach called ANN-GA (artificial neural networks-genetic algorithms) is proposed in this research. This approach combines ANN and GA to determine an optimal neural network architecture. The performance of the ANN-GA model is compared to the Levenberg–Marquardt backpropagation (LM) algorithm. ANOVA results show that the feed per revolution have a significant influence on surface roughness, followed by the chemical treatment of fibers, while machining direction has a smaller effect. The ANN-GA model demonstrates good accuracy in surface roughness prediction compared to the LM algorithm. [ABSTRACT FROM AUTHOR]

The key challenge in tissue engineering is to develop structures with sufficient characteristics that will replicate the natural extracellular matrix (ECM) to promote tissue regeneration. Copper and manganese minerals substituted hydroxyapatite (CuMn-HA)/chitosan (CTS)–polyvinyl pyrrolidone (PVD) were fabricated by sol–gel and solvent casting techniques, respectively. Fabricated biocomposites have been identified by the use of Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) for the analysis of functional groups, crystalline phases and surface morphology. The XRD and FTIR spectra of the biocomposite revealed the existence of functional groups and crystalline phases in the biocomposites. The SEM images revealed biocomposite and inclusion of CuMn-HA in rough morphology. Physicochemical characteristics such as swelling and compressive strength have been examined in the preparation of biocomposite materials. Biocomposites (10, 20, 30 wt% of CuMn-HA biocomposite) exhibited great material characteristics where 30% displayed the minimum swelling and a compressive property of 71 MPa was tested. It displayed the highest inhibition zone towards bacteria population and was also found to be blood-compatible with a haemolytic value of only about 2.5% relative to other compounds. Finally, in-vitro cell cultures were performed in biocomposite scaffolds to determine the effects of CuMn-HA on the proliferation of osteoblast cells, resulting in biocomposites contrast to pristine PVD/CTS. [ABSTRACT FROM AUTHOR]

In the present paper, we describe how a robust and fundamental methodology was developed for extraction and determination of a principal natural toxin compound, simplexin, from a series of bulk biocomposites. These complex matrices were fabricated by direct encapsulating either ground plant particles or an ethanolic crude extract of the Australian toxic pasture plant Pimelea trichostachya in the biodegradable polymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Proton nuclear magnetic resonance spectroscopy was initially employed to examine the chemical compositions of these complicated systems. Then, a more sensitive strategy was developed and validated by combining solid-phase extraction and ultrahigh-performance liquid chromatography hyphenated with a quadrupole Orbitrap mass spectrometer for the quantification of simplexin embedded in different biocomposites. Satisfactory linearity (R2 > 0.99) and recovery ranges (86.8–116%) with precision (relative standard deviations) of between 0.2 and 13% (n = 3) were achieved from seven biocomposites. The established protocol was further shown to be accurate and reliable in confirming the homogeneous distribution of the simplexin in different biocomposite formulations. A limited mass transfer of simplexin (< 3.5%) from one of the biocomposites into a simulated but sterilized in vitro rumen environment after a 10-day incubation was also revealed by utilizing the method. This quantitative analysis of targeted natural product within plant material-integrated polymeric platforms has potential application when controlled release is required in the bovine rumen and other biological systems. [ABSTRACT FROM AUTHOR]

New biocomposites are increasingly being developed and applied in engineering and manufacturing. The reinforcement type used in biocomposite is one of the major factors that greatly affect the machinability of biocomposite. This study investigated the drilling of two biocomposites (polypropylene-based biocomposite reinforced with biocarbon M1 (30 wt% biocarbon + PP/POE/MAPP) and chopped miscanthus fibers M2 (30 wt% miscanthus + PP/POE/MAPP)). A full factorial design was used for this study. The effects of drilling parameters and reinforcement types on surface roughness, thrust force, specific cutting energy, fine particles, and ultrafine particle generation were measured and analyzed. The results show that the thrust force and specific cutting energy during drilling of biocomposite M1 is bigger than that of biocomposite M2 under the same cutting conditions. However, the surface roughness and fine dust emitted when drilling biocomposite M1 are smaller than those from biocomposite M2, respectively. The reinforcement types of biocomposite, cutting parameters and drill diameter greatly affected fine particles emission. Meanwhile, the cutting conditions are not statistically significant for ultrafine particle generation during dry drilling of both biocomposites. [ABSTRACT FROM AUTHOR]

Owing to its viscoelastic nature, axon exhibits a stress rate-dependent me- chanical behavior. An extended tension-shear chain model with Kelvin-Voigt viscoelas- ticity is developed to illustrate the micromechanical behavior of the axon under dynamic torsional conditions. Theoretical closed-form expressions are derived to predict the de- formation, stress transfer, and failure mechanism between microtubule (MT) and tau protein while the axon is sheared dynamically. The results obtained from the present an- alytical solutions demonstrate how the MT-tau interface length, spacing between the tau proteins, and loading rate affect the mechanical properties of axon. Moreover, it is found that the MTs are more prone to rupture due to the contributions from the viscoelastic effects. Under the torsional force, the MTs are so long that the stress concentrates at the loaded end where axonal MTs will break. This MT-tau protein dynamics model can help to understand the underlying pathology and molecular mechanisms of axonal injury. Additionally, the emphasis of this paper is on the micromechanical behavior of axon, whereas this theoretical model can be equally applicable to other soft or hard tissues, owning the similar fibrous structure. [ABSTRACT FROM AUTHOR]

Nano-hydroxyapatite (nHA) based polymer biocomposites have been widely used in biomedical industry because of biocompatibility and improved mechanical properties. The goal of this study was to produce ultra high molecular weight (UHMW) polyethylene/nHA composite via heat-assisted friction stir processing and to investigate the effects of process parameters on composite’s microstructure and tensile characteristics. The process parameters include rotational speed (ω), feed rate (f), volume fraction of nHA (v), and shoulder temperature (T). ANOVA was performed to identify the significant process parameters. Moreover, empirical models for tensile properties were developed and validated. Microscopic analysis revealed that the process parameters substantially affect the dispersion of reinforcing particles, formation of defects, and mixing of materials. Low levels of ω and T and high levels of f and v lead to defects (agglomeration of reinforcing particles, voids, and channels). Five percent volume of nHA with medium levels of other process parameters resulted in better material mixing, minimum defects, and better mechanical properties (10% increase in strength with only 1% reduction in percent elongation, relative to the parent material). [ABSTRACT FROM AUTHOR]

Open-porous titanium scaffolds have been widely investigated for orthopaedic and dental applications because of their ability to form composites via bone ingrowth into pores and promote implant fixation with mother bone. In this work, porous titanium scaffolds coated with a diamond-like carbon were produced, and their ability to form biocomposites was evaluated through in vivo experiments. Three types of the open-porous scaffolds made of spongy titanium granules (porosity 0.3, 0.4 and 0.5, Young's modulus 4.4, 3.5 and 0.6 GPa) were implanted into a bone defect of sheep. Time dependences of the Young's modulus of titanium scaffold-bone tissue biocomposites were determined through the measurement of Young's modulus of the extracted scaffolds after 4, 8, 24 and 52 weeks of surgery. The Young's modulus of biocomposite is dependent not only on the time of composite formation but also on the porosity of scaffold. [ABSTRACT FROM AUTHOR]

A 3D-matrix is obtained on the basis of sintered composite material from bioactive glass and dicalcium phosphate. The effect of the component ratio of the mix and the firing temperature of the blanks on the phase composition, porosity, strength, and dissolution kinetics of sintered samples is determined. It is shown that directed formation is possible in sintered composites of highly resorbable phases. 3D-Modeling is used to obtain a personalized implant. [ABSTRACT FROM AUTHOR]

This work is part of a project aimed at developing a new biocomposite material that can be used for thermal insulation purposes. This material is mainly composed of sunflower stem chips. A chitosan-based biomatrix is used as binder between them. We focus here only on the mechanical response of this biocomposite. The goal is to investigate experimentally the link between its macroscopic response and phenomena which occur at the scale of the constituents, namely the bark and pith chips. The grid method, which is one of the full-field measurement systems employed in experimental mechanics to measure displacement and strain fields, is employed because of the very heterogeneous nature of this material. This heterogeneity is not only due to the contrast in rigidity between bark and pith, but also to the presence of voids within the material. These voids, as well as the presence of pith, lead us to develop and employ a specific marking procedure for the specimen surface under investigation. Two values for the mass percent fraction of chitosan are investigated, to observe the influence of this parameter on the global stiffness of the material and on local phenomena that occur in its bulk. The full-field measurement technique employed here leads us to detect and quantify significant heterogeneities in the strain fields, which are closely related to the material heterogeneities themselves. [ABSTRACT FROM AUTHOR]

A resorbable composite which acts as a active barrier in guided bone regeneration was fabricated using chitosan, demineralized bone matrix and bone ash. Its potential to form bone like apatite in simulated body fluid was assessed in this study. The mechanical strength of these composites was correlated with bone ash ratios and composites with better tensile strength were studied for their acellular bioactivity by incubating in simulated body fluid for 21 days. Composites without bone ash did not show acellular bioactivity which was confirmed by thermogravimetric analysis. In case of biocomposites with bone ash, there was an increase in residual weight indicating the mineralization of the composite. The composite containing bone ash has shown the peaks related to phosphate vibrations in its Fourier-transform infrared spectrum. Scanning micrographs revealed formation of apatite like crystals on its surface. Ca/P ratio was found to be 1·7 which is nearer to that of natural bone. Thus, prepared composites can be used as resorbable biocomposite in maxillofacial and oral defects. [ABSTRACT FROM AUTHOR]

A series of composite materials based on dicalcium phosphate dihydrate and bioactive glass 50S25N5P with physiologically safe pH and compression strength from 4 to 22 MPa has been developed. The composites obtained are resorbable and can be used in trauma treatment and bone tissue disease. [ABSTRACT FROM AUTHOR]

The results of wet two-stage synthesis of tricalcium phosphate followed by high-temperature treatment are reported. The effect of incorporating tricalcium silicate and alkaline silicate glasses in formation of biocomposite materials based on dicalcium phosphate dihydrate (DCPD) was examined. It was found that use of the bioactive glass 50S25N5P in the amount of up to 10% of the mass content increases the compressive strength and pH to a physiologically safe level in the composite material in comparison to unmodified DCPD. The composite obtained ensures formation of osteoid tissue for 30 days. [ABSTRACT FROM AUTHOR]

Impedance spectroscopy is a rapidly developing technique for the transduction of biosensing events at the surface of an electrode. The immobilization of biomaterial as DNA strands on the electrode surface alters the capacitance and the interfacial electron transfer resistance of the conductive electrodes. The impedimetric technique is an effective method of probing modifications to these interfacial properties, thus allowing the differentiation of hybridization events. In this work, an avidin bulk-modified graphite–epoxy biocomposite (Av-GEB) was employed to immobilize biotinylated oligonucleotides as well as double-stranded DNA onto the electrode surface. Impedance spectra were recorded to detect the change in the interfacial electron transfer resistance ( R et) of the redox marker ferrocyanide/ferricyanide at a polarization potential of +0.17 V. The sensitivity of the technique and the good reproducibility of the results obtained with it confirm the validity of this method based on a universal affinity biocomposite platform coupled with the impedimetric technique. [ABSTRACT FROM AUTHOR]