Drawing Speed Research Articles

Experimental Determination and Calculation of the Wire Drawing Force in Monolithic Dies on Straight-Line Drawing Machines

In this article, a mathematical model has been developed for calculating the energy-power parameters of the drawing process in monolithic dies on straight-line drawing machines, and its adequacy has been validated in experimental wire drawing on a laboratory automated drawing machine. The program allows us to calculate drawing stress, drawing force, tensile strength and yield strength of the alloy after wire drawing, safety factor, and drawing power. The developed mathematical model differs in that it allows us to evaluate the uniformity of deformation over the wire section, depending on the technological parameters of the deformation zone, namely, the semi-angular die, the coefficient of friction and the degree of deformation. To select the technological parameters of the deformation zone, which ensure uniform deformation over the wire cross-section, a nomogram was compiled. The equations of hardening during nickel NP2 wire drawing are obtained. The calculation of energy-power parameters of drawing nickel NP2 (Ni 99.6) wire ∅1.8 mm from ∅4.94 mm wire rod is given. Experimental studies have been carried out to determine the energy-power parameters of nickel wire drawing on a laboratory drawing machine with an installed ring strain gauge to determine the drawing force. A change in the friction coefficient by 0.02 when drawing nickel wire leads to an increase in stress and drawing force by 20%. To improve the accuracy of the developed mathematical model, it is shown that in the future, it would be necessary to conduct experimental studies on a laboratory drawing machine to determine the effect on the energy-power parameters of the drawing process of the values of technological parameters entered into the program as constant real values, such as the friction coefficient, die half-angle, drawing speed, and back tension.

An LSTM-based adaptive prediction control model for the wire diameter control of high-precision optical fiber drawing machines

Reducing inconsistencies in fiber diameter has always been a focus of research on optical fiber drawing machines (OFDM). Based on an established mathematical model for OFDM, we adopted a long short-term memory (LSTM)-based neural network to predict fiber wire diameter and utilized these results to feedback and control the drawing speed, thereby achieving high precision control of the wire diameter. We trained the proposed network using relevant data from two different fiber drawing processes, allowing it to learn the long-term and short-term correlations in the data. Additionally, we evaluated the performance of the model using root mean square error (RMSE) and R2 as indicators. The experimental results show that network complexity has a considerable impact on the precision of fiber wire diameter prediction. We also established that two LSTM hidden layers with 64 neural units in each layer are the most suitable for the proposed network structure. The network with such a structure has the smallest RMSE value in the validation set and the largest R2 in the testing set. Subsequently, the optimal network structure was used to conduct a multi-timespan wire diameter prediction experiment. According to the experimental results, the LSTM-based wire diameter prediction model still has a satisfactory predictive effect when the time is as long as 50 s, suggesting that the precision and robustness of this network are high. When this method is applied to the actual wire drawing process, the wire diameter error can be controlled to within ± 1.8 μm when the target wire diameter is 0.66 mm, indicating that the wire diameter precision is greatly enhanced. Results indicate that using LSTM-based prediction and control effectively avoids the interference of other factors in the process of wire drawing. Therefore, we remedied the time delay issue of conventional wire diameter control methods. Also, compared with conventional methods, we achieved more precise and robust control of wire diameter.

Study and development of methods for predicting the physical and mechanical properties of thin wire and metal cord

Predicting the physical and mechanical properties of thin wire and metal cord will ensure an increase in the quality of latuned thin wire, a reduction in the number and time of technological pauses, and increase the manufacturability of metal cord twisting. Considering that the deformation manifests anisotropy of the properties of thin wire, the prediction of physical and mechanical properties and the degree of unevenness of deformation becomes an urgent task.The paper studies that an increase in the drawing speed of a thin wire leads to the acquisition of a more uniform and fine‑grained structure. The dependences of the physico‑mechanical properties of thin latuned wire after the metal cord is twisted on the speed of fine drawing are developed. The effect of the deformation rate on the microhardness of a thin steel wire is investigated. It is determined that in order to increase the productivity of metal cord twisting, it is necessary to bring the dependence of the increase in hardness and equivalent stresses in metal cord wires to a linear form by changing the speed of the twisting at its individual stages. For practical use, the dependences of the mechanical properties of a thin wire of strength class HT on the drawing speed are derived.During the analysis, the results were obtained, which are applicable in the design of new or modification of existing routes for drawing thin wire, as well as in the design of new metal cord structures.

Comparison of Temperature Distribution between TWIP and Plain Carbon Steels during Wire Drawing

The effect of the thermal properties of steels on wire drawing behavior has been investigated to understand and improve the wire drawing process. Finite element analysis and experimental tests were conducted to analyze the temperature distribution of the deformed specimens with different thermal properties. The thermal properties of twinning-induced plasticity (TWIP) steel were measured and compared with those of plain carbon steel. Based on the measurement of thermal properties, wire drawing behaviors were systematically compared with thermal conductivity of the specimen (k) using plain low-carbon steel with high k and TWIP steel with low k. The results revealed that the k of TWIP steel was approximately one third of that of low-carbon steel, and the thermal expansion coefficient of the TWIP steel was approximately 50% higher than that of low-carbon steel in the temperature range of 26-400 °C. The temperature distributions in the wire strongly depended on the k of the wire during wire drawing. TWIP steel exhibited higher maximum temperature, and took a longer time to attain the equilibrium temperature than low-carbon steel during wire drawing owing to the low k. The maximum temperature of the die increased with decreasing k of the wire, indicating that die wear can increase with decreasing k of the wire. Therefore, reducing the drawing speed is suggested for a wire with low k, such as high-alloyed metals, especially for TWIP steels.

A study of the formability of stainless steel foils during micro deep drawing

Stainless steel foils are extensively used in the manufacture of micro-metallic products for their excellent corrosion resistance, high mechanical strength and superior ductility. In the present work, stainless steel foils with 50 μm thickness were annealed at temperatures ranging from 750 to 1150 °C for 5 min and then cupped at drawing speeds ranging from 0.1 to 2 mm/min. The formability of metal foils was systematically investigated and the quality of drawn cups via micro deep drawing (MDD) was discussed. The results show that the total elongation of metal foils appears a gradual increase when annealing temperature rises from 750 to 950 °C. With a further increase of annealing temperature from 950 to 1150 °C, both the ultimate tensile strength and the total elongation decline sharply, while the scatter of stress increases. The results of MDD tests show that wrinkling problem becomes increasingly significant on the drawn cups whilst thickness distribution on the drawn cup mouth become quite nonuniform with the increase of drawing speed from 0.1 to 2 mm/min. Overall, optimal annealing temperature and drawing speed are obtained with the purpose of manufacturing high quality micro circular cups.

Detection of cognitive impairment from eSAGE cognitive data using machine learning

AbstractBackgroundAlzheimer’s disease is a neurodegenerative disease that affects many people worldwide. Many cognitive screening tests are available, with one example being eSAGE – a self‐administered exam (Scharre et al., 2017)1. eSAGE is a valid and reliable cognitive assessment tool to detect mild cognitive impairment or early dementia. It has been implemented as an app in BrainTest®, with sample screenshots in Figure 1. While eSAGE provides diagnostic results of its own, there is a potential to apply machine learning methods to the responses to obtain better diagnostic results.MethodeSAGE results1 and behavioral data from BrainTest® were obtained for 69 subjects, each with a diagnosis of normal cognition, mild cognitive impairment, or dementia. 84 metrics were extracted, including the time that subjects spent on each test page, and drawing speed and line straightness from the construction test problems (Table 1). The hypothesis was that cognitive impaired subjects would show different behavioral patterns (e.g., spend more time on questions, change answers often) compared to those of normal cognition. Different machine learning methods including logistic regression and gradient boosting are built over the metrics to classify between cognitive impairment and normal cognition.ResultLogistic regression classifies those with cognitive impairment vs normal cognition with a recall of 100% and ROC of 75.32% and classifies those with MCI vs normal cognition with a recall of 76% and ROC of 79.45% (Table 2). The most important features (those highest weighted metrics used to differentiate the diagnostic classification) for both these classifications were similar (Table 3). Individuals with normal cognition had, on average, longer connected line segments (not lifting their finger off the tablet) when performing the Modified Trails B task (Figure 1). They also spent less time completing their verbal fluency and picture naming tasks (Table 3). See Table 2 and 3 for other findings.ConclusionBehavioral features extracted from self‐administered eSAGE with the BrainTest® app are predictive of cognitive impairment diagnosis by logistic regression and gradient boosting. Important features identified suggest executive processing time lengthens as one progresses from normal to impaired cognition.Reference 1Scharre et al. (2017). Alzheimer’s Research & Therapy, 9, 44.

Effect of Colorants and Process Parameters on the Properties of Dope-Dyed Polylactic Acid Multifilament Yarns.

The color of textile fibers is typically imparted by submersion in a high-temperature dye bath. However, the treatment of the effluent is challenging and the textile industry is therefore a major source of water pollution. Current fashion trends favor biobased polymers such as polylactic acid (PLA) but exhaust dyeing at high temperatures causes hydrolytic degradation, reducing the crystallinity and tenacity of the yarn. To preserve the mechanical properties of PLA-based textiles, an alternative to exhaust dyeing called dope dyeing can be used, wherein colorants are incorporated into the polymer matrix during melt spinning. We evaluated this process by dope dyeing PLA with several colorants, then testing the thermal, physical, and mechanical properties of the yarn and the physical properties of circular-knitted fabrics. Although the colorants affected the crystallization behavior at lower cooling rates, during the melt-spinning process, the drawing speed had a greater effect on the crystallinity and mechanical properties of the dyed yarn. Scanning electron microscopy revealed that the colorants were well dispersed in the PLA matrix. We found that the colorants did not affect the physical properties of the knitted fabric. Our results can be used to develop more environmentally beneficial dope-dyed PLA yarn with improved mechanical properties.

STUDY OF DEFORMATION AND CONTACT HEATING OF WIRE DURING THE HIGH-SPEED DRAWING PROCESS IN A MONOLITHIC DIE

This article presents the results of analytical studies of the deformation and contact heating of the wire, depending on the drawing technological parameters. The analysis was carried out by the calculation method and the computer simulation method in the QForm package based on the finite element method. The increase in the temperature of the wire during drawing in a monolithic die consists of deformational heating and heating caused by sliding friction on the “wire – die” surface. In the course of the research, it was found that the half-angle of the die has an effect on the uniformity of the distribution of deformation and, as a consequence, on the deformation heating over the wire section. With an increase in the die half-angle in the surface layers, the metal heats up to higher temperatures than in the central section. The values of deformation heating obtained by calculation are consistent with the results obtained in a numerical experiment. The deformation heating in both cases does not exceed 50 °C. An increase in the drawing speed from 10 to 40 m/s leads to an increase in deformation heating by 2–4 °C. Heating of the wire due to contact sliding friction, depending on the technological parameters of drawing, can reach 300 °C. An analysis of the temperature field during wire heating due to sliding friction in computer simulation showed that the proportion of metal heated to a temperature above 150 °C does not exceed 5%. About 50% of the metal volume is heated only due to deformation, and 45% of the metal volume is heated to temperatures of 70–150 °C due to deformation and heat conduction from the surface layer heated due to sliding friction. A comparative analysis of the calculated values and the results of computer simulation showed that both methods show similar results. The advantage of computer simulation is the ability to estimate the temperature field over the wire section, and the advantage of the calculation method is the high speed of obtaining information in the evaluation calculations.

Characteristics of Drawing Process Differentiate Alzheimer's Disease and Dementia with Lewy Bodies.

Early differential diagnosis of Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) is important for treatment and disease management, but it remains challenging. Although computer-based drawing analysis may help differentiate AD and DLB, it has not been studied. We aimed to identify the differences in features characterizing the drawing process between AD, DLB, and cognitively normal (CN) individuals, and to evaluate the validity of using these features to identify and differentiate AD and DLB. We collected drawing data with a digitizing tablet and pen from 123 community-dwelling older adults in three clinical diagnostic groups of mild cognitive impairment or dementia due to AD (n = 47) or Lewy body disease (LBD; n = 27), and CN (n = 49), matched for their age, sex, and years of education. We then investigated drawing features in terms of the drawing speed, pressure, and pauses. Reduced speed and reduced smoothness in speed and pressure were observed particularly in the LBD group, while increased pauses and total durations were observed in both the AD and LBD groups. Machine-learning models using these features achieved an area under the receiver operating characteristic curve (AUC) of 0.80 for AD versus CN, 0.88 for LBD versus CN, and 0.77 for AD versus LBD. Our results indicate how different types of drawing features were particularly discriminative between the diagnostic groups, and how the combination of these features can facilitate the identification and differentiation of AD and DLB.

Random Laser Based on Ytterbium-Doped Fiber with a Bragg Grating Array as the Source of Continuous-Wave 976 nm Wavelength Radiation

A random narrow-linewidth lasing at a wavelength of 976 nm was obtained in an ytterbium-doped germanophosphosilicate fiber with an array of weakly reflecting fiber Bragg gratings (FBGs). A random laser cavity was formed by implementing the standard phase mask method of FBG inscription directly during the fiber drawing process. The UV radiation pulses of a KrF excimer laser (248 nm wavelength) synchronized with the fiber drawing speed were used to fabricate the in-fiber array of hundreds of similar FBGs. The developed laser’s slope efficiency in the backward-pumping scheme was measured as high as 33%. The stable continuous-wave operation mode of the laser was detected. The magnitude of the laser power fluctuations depends linearly on the cavity length. The random laser cavity modified with a single highlyreflected (90%) FBG demonstrates significantly better power stability and higher slope efficiency than the same one without an FBG.

The Effect of Drawing in Conventional and Hydrodynamic Dies on Structure and Corrosion Resistance of Hot-Dip Galvanized Zinc Coatings on Medium-Carbon Steel Wire.

The paper presents the impact of the drawing method on the microstructure and corrosion resistance of galvanized steel wires. The microstructural tests confirmed that, in the drawing speed range v = 5–20 m/s, the use of hydrodynamic dies creates more favorable conditions for the deformation of the soft zinc coating on the hard steel core. The increase in friction at the wire/die interface in the conventional method, as compared to the hydrodynamic method, contributed to the decrease in coating thickness and the increase in the diffusion layer, and the higher the drawing speed, the greater the differences between the analyzed drawing methods. In the conventional method, while drawing at high speeds v = 20 m/s, there was a two-way diffusion and complete remodeling of the ζ phase in δ1. In the hydrodynamic method, at the speed of 20 m/s, in the analyzed micro-areas, places showing the presence of the ζ phase, partially dispersed in the layer with pure zinc, were observed. A corrosion tests comparison between conventionally and hydrodynamically drawn wires showed an improved behavior of the latter. The greater mass in the surface layer of pure zinc, a substrate for the corrosion product in hydrodynamically drawn wires, reacted, creating insulation from the white corrosion produced. The compressive stresses in the hydrodynamic dies caused by the high pressure of the lubricant on the circumference of the wire closed the microcracks on its surface, which additionally sealed the zinc coating.

How Facial Symmetry Influences the Learning Effectiveness of Computer Graphic Design in Makeup Design

This study explored the learning effectiveness of drawing makeup designs by computer graphic design and compared the learning differences between traditional hand-drawn and computer-assisted teaching in cosmetology students at universities. The statistical analysis methods of factor analysis, descriptive statistical analysis, and paired sample t-test are used to analyze the difference in students’ learning attitudes before and after the course. It also explored students’ learning effectiveness. The subjects were 55 students from a cosmetology department of a university in Taiwan. The results showed that using a computer tool to create makeup designs improved the overall student learning effectiveness and effectively promoted students’ interest in learning. Moreover, through focus group interviews, changes in the learning effectiveness that were brought about by the use of computer graphic design tools were obtained. Among them, the mirror function could best meet the needs of students for makeup symmetry and design drawing speed and improve their satisfaction with computer graphic makeup. The results of this study are improving the learning effectiveness, maintaining a positive attitude and increasing willingness to learn, and the systematization and digitization of makeup design, and the results could promote teachers to obtain more efficient teaching quality, improve students’ professional skills, and result in better learning results.

Finite element simulations and experiments of cold drawing of stainless steel rods

Drawing is a commonly used metal forming method in the industry, it is an effective method to manufacture wires, bars or tubes with smooth surfaces and high precision in size. In this study, the effects of several forming parameters including die angle, reduction ratio, bearing ratio, friction coefficient and drawing speed on the product dimensions of AISI-316 stainless steel rods are investigated. The drawing processes are first simulated using different forming parameters, an empirical formula relating the product diameter to the forming parameters is then derived and verified by experiment. The percentage difference between the experimental, simulated and calculated results is found to be less than 1%. Using this formula, the dimensions of cold-drawn AISI-316 stainless steel can be predicted more easily and quickly. Metallographic observations and hardness tests are also conducted.

Influence of the drawing process on corrosion behaviour of hot-dip galvanised wires

The phenomenon of corrosion on wires and springs covered with an anti-corrosive zinc coating was investigated. To assess the corrosion resistance of galvanised wires, tests were carried out in the standard neutral salt spray corrosion test and in the sulphur dioxide test with general moisture condensation. The spring corrosion process depends on the wire drawing technology. The research showed that the higher the drawing speed and angle, the more dynamic the corrosion development.

Influence of dynamic inhomogeneity of the stress-strain state on the modes of wire drawing in a monolithic conical die

The study of the wire drawing speed influence in a monolithic conical die on the stressstrain state inhomogeneity and drawing modes was presented. It was shown that the nonuniformity of stresses and strains during drawing in monolithic round dies could be divided into two types: static and dynamic. When drawing a round wire in a monolithic conical die, stress-strain state inhomogeneity occurs in the deformation zone, which results in microcracks at the wire center. The destruction degree depends on the value of Δ-factor, which characterizes the shape of the deformation zone. When the drawing speed increases, an additional speed or dynamic deformation inhomogeneity arises in the deformation zone due to the resulting acceleration and an increase in stresses. This causes a significant increase in the parameter Δ and the working half-angle of die, called “dynamic”. Analytical expressions were obtained for calculating the “dynamic” die angle and its velocity part. The analytical expressions analysis was carried out, the relationships between parameter Δ and the die half-angle on the drawing speed were obtained. A graphical dependence of the change in the safe zone, which excludes the destruction of the wire, on the value of the “dynamic” die angle and the degree of single deformation at various drawing speeds was plotted. It was shown that the “safe” zone decreases in proportion to the increase in the drawing speed. Solutions were proposed that provide an “acceptable” value of the parameter Δ for high-speed drawing. For this necessary to design wire drawing schedules using the maximum possible reductions per pass, and the values of the working half-angles of the wire drawing die, providing “static” inhomogeneity, should be reduced by the value of half-angles dynamic change. Wire drawing should be carried out at minimum tensile stresses.

Polyurethane shape memory filament yarns: Melt spinning, carbon-based reinforcement, and characterization

The aim of this work was to develop and characterize polyurethane-based shape memory polymer filament yarns of a suitable diameter and thermo-mechanical performance for use in tailored multi-sectorial applications. Different polymer compositions – pure shape memory polyurethane and shape memory polyurethane composites with 0.3 and 0.5 wt.% of multi-walled carbon nanotubes or carbon black as additives – were studied. Filaments were obtained using a melt spinning process that allowed the production of the permanent and temporary shape of the shape memory polyurethane filament. Two drawing speeds (20 and 32 m/min) were studied. Characterization techniques such as the tensile test, differential scanning calorimetry, and dynamic mechanical analysis were used to investigate the shape-memory effect of the filaments. Pure and additive shape memory polyurethane filament yarns of a controlled diameter were produced. The results indicated that the pure shape memory polyurethane on the temporary shape had the highest tensile strength (234 MPa). Filaments with carbon black revealed a significant strain (335%) in the permanent shape with respect to the other filaments. The melt spinning process influenced the soft segment glass transition temperature (Tgs) significantly, with a decrease in the temporary shape (first heating) as compared to the permanent shape (second and third heating). However, only the 0.5% multi-walled carbon nanotubes additive clearly influenced the filament, increasing the Tgs by 10°C. The additives also influenced the shape-memory effect, obtaining an increased fixity ratio (up to 97%) with the multi-walled carbon nanotubes additive and an increased recovery ratio (up to 86%) with the carbon black additive.

Influence of Lanthanum-Doped Tungsten Wire Drawing Process on Microstructure and Properties.

A reasonable preparation processing of Lanthanum-doped tungsten wire plays a decisive role in the final properties of the wire. This paper gives the optimum drawing process parameters of lanthanum-doped tungsten wire with φ1.00 mm–φ0.50 mm and explains the phenomenon of coarsening of fiber-like grains in the preparation processing of tungsten wire. The final optimum process parameters of lanthanum-doped tungsten wire are given: the temperature is 950 °C (the first pass temperature is 950 °C, and the temperature decreases by about 20 °C for each pass), the compression ratio is 15%, mold temperature is 550 °C, because of the limitation of equipment conditions, the wire drawing speed is fixed at 0.19 m/s. It is found that the fiber-like grains of the tungsten wire coarsen when the temperature is too high, and it is prone to breakage when the temperature is too low during the drawing process. When the compression ratio is too high (for example, 22%), there is a negative impact on the surface quality and the straightness of the tungsten wire. When the compression ratio is too low, the processing die time is increased, and the production cost is increased.

Viscoplastic deformation of cotton fabric‐reinforced polypropylene composites

AbstractIn this work, cotton fabric‐reinforced polypropylene laminates (CFRLs) were prepared as an example to analyze the effect of viscoplastic deformation on the mechanical properties of natural fiber‐reinforced composites. Compared with neat polypropylene (PP), the tensile strength and modulus of CFRLs are significantly enhanced in all directions. However, CFRLs are more prone to plastic deformation than PP during static tensile tests. The tensile strength of CFRLs could be affected by the processing factors. As the drawing speed was reduced from 20 to 0.1 mm/min, the tensile strength of CFRLs decreased by 27%. Cyclic tensile tests were used to analyze the effect of viscoplastic deformation on the tensile strength of CFRLs, and the results showed that when the viscous deformation increased, the strain increased, leading to rapid fracture of CFRLs under cyclic tensile stress much lower than the tensile strength. By simulating the stress conditions of pressure vessels and pipes with different curved surfaces, CFRLs are shown to be more suitable for cylindrical curved structures, which has developable surface; While, they are not suitable for complex curved structures, such as spherical surfaces, that are undevelopable surface.

Investigations of Formability and Dynamic Recrystallization Development of Titanium Alloys During Dieless Wire Drawing Processes

This study investigates the formability and grain size evolution during the dieless wire drawing process of titanium alloy Ti–6Al–4V. First, thermocompression tests of Ti–6Al–4V billets are conducted to obtain their flow stresses at different temperatures and strain rates. Dynamic recrystallization (DRX)‐related constants and grain size prediction models for titanium alloy Ti–6Al–4V are established from the flow stress curves through regression analyses. Then, a finite element software DEFORM 2D coupled with the established DRX models is adopted for DRX volume fraction and grain size evolution simulations of titanium alloy Ti–6Al–4V during dieless wire drawing processes. The effects of various drawing conditions, such as drawing speed, drawing temperature, and area reduction, on the formability of the wire after the dieless drawing process are discussed. Finally, a dieless drawing machine with a high‐frequency induction heating apparatus and a cooling system is developed. A series of experiments of dieless drawing of titanium alloy Ti–6Al–4V wires at different drawing speeds, drawing temperatures, and cooling rates are conducted. The analytical forming limits of area reductions and grain sizes are compared with experimental values to validate the finite element analysis and DRX models.

Nano-Structured Ridged Micro-Filaments (≥100 µm Diameter) Produced Using a Single Step Strategy for Improved Bone Cell Adhesion and Proliferation in Textile Scaffolds.

Textile scaffolds that are either 2D or 3D with tunable shapes and pore sizes can be made through textile processing (weaving, knitting, braiding, nonwovens) using microfilaments. However, these filaments lack nano-topographical features to improve bone cell adhesion and proliferation. Moreover, the diameter of such filaments should be higher than that used for classical textiles (10–30 µm) to enable adhesion and the efficient spreading of the osteoblast cell (>30 µm diameter). We report, for the first time, the fabrication of biodegradable nanostructured cylindrical PLLA (poly-L-Lactic acid) microfilaments of diameters 100 µm and 230 µm, using a single step melt-spinning process for straightforward integration of nano-scale ridge-like structures oriented in the fiber length direction. Appropriate drawing speed and temperature used during the filament spinning allowed for the creation of instabilities giving rise to nanofibrillar ridges, as observed by AFM (Atomic Force Microscopy). These micro-filaments were hydrophobic, and had reduced crystallinity and mechanical strength, but could still be processed into 2D/3D textile scaffolds of various shapes. Biological tests carried out on the woven scaffolds made from these nano-structured micro filaments showed excellent human bone cell MG 63 adhesion and proliferation, better than on smooth 30 µm- diameter fibers. Elongated filopodia of the osteoblast, intimately anchored to the nano-structured filaments, was observed. The filaments also induced in vitro osteogenic expression, as shown by the expression of osteocalcin and bone sialoprotein after 21 days of culture. This work deals with the fabrication of a new generation of nano-structured micro-filament for use as scaffolds of different shapes suited for bone cell engineering.