Investigation of Porosity Relationship in Additive Manufactured Novel Bone Scaffold

2014 ◽  
Vol 592-594 ◽  
pp. 836-841
Author(s):  
Kishore A. Arul ◽  
Begum S. Rashia ◽  
G. Arumaikkannu

Additive manufacturing (AM) is one the advanced process for building up a component layer by layer, with one layer of material was bonded to the previously laid layer using a 3D design data. In the field of medical science AM is very much useful in the development of Bone Scaffolds. The bone scaffold needs the good level of porosity for the cultivation of cells. In this work, an algorithm for a novel structure with the theme of flexible porosity was introduced. Scaffold models were developed using CATIA V5 for four different porosities. The novel structures made of Poly Amide (PA 2200) material were fabricated using a commercially available Selective Laser Sintering machine (SLS). The differences in scaffold theoretical and experimental porosities were investigated and the percentage of error was discussed.

Author(s):  
S Rashia Begum ◽  
M Saravana Kumar ◽  
M Vasumathi ◽  
Muhammad Umar Farooq ◽  
Catalin I Pruncu

Additive manufacturing is revolutionizing the field of medical sciences through its key application in the development of bone scaffolds. During scaffold fabrication, achieving a good level of porosity for enhanced mechanical strength is very challenging. The bone scaffolds should hold both the porosity and load withstanding capacity. In this research, a novel structure was designed with the aim of the evaluation of flexible porosity. A CAD model was generated for the novel structure using specific input parameters, whereas the porosity was controlled by varying the input parameters. Poly Amide (PA 2200) material was used for the fabrication of bone scaffolds, which is a biocompatible material. To fabricate a novel structure for bone scaffolds, a Selective Laser Sintering machine (SLS) was used. The displacement under compression loads was observed using a Universal Testing Machine (UTM). In addition to this, numerical analysis of the components was also carried out. The compressive stiffness found through the analysis enables the verification of the load withstanding capacity of the specific bone scaffold model. The experimental porosity was compared with the theoretical porosity and showed almost 29% to 30% reductions when compared to the theoretical porosity. Structural analysis was carried out using ANSYS by changing the geometry. Computational Fluid Dynamics (CFD) analysis was carried out using ANSYS FLUENT to estimate the blood pressure and Wall Shear Stress (WSS). From the CFD analysis, maximum pressure of 1.799 Pa was observed. Though the porosity was less than 50%, there was not much variation of WSS. The achievement from this study endorses the great potential of the proposed models which can successfully be adapted for the required bone implant applications.


2019 ◽  
Vol 1 (5) ◽  
pp. 63-68 ◽  
Author(s):  
A. A. Dolgalev ◽  
D. S. Svyatoslavov ◽  
V. A. Put ◽  
I. V. Rzhepakovsky ◽  
D. S. Eldashev ◽  
...  

According to the pre-made patterns of 3D-design and prototyping patterns during the experiment, defects of the lateral portion of the ram's lower jaw were created using the piezosurgical technique. The defects were replaced by plastic implants obtained by the method of layer-by-layer melting of FDM-printing (fusing deposition modeling, FDM) and fixing titanium screws to the jaw body. In the time interval, plastic implants are replaced by titanium ones, obtained using SLS technology -selective laser sintering using a 3D-printer. In order to study the processes of reparative osteogenesis, microsamples of tissues of the periimplantation zone were analyzed. As a result, signs of osteo- and fibro-osseointegration were identified. The data obtained are regarded as a prerequisite for further clinical trials of the developed protocols for the sequential replacement of defects of the jaws using 3D-printing.


Nanoscale ◽  
2018 ◽  
Vol 10 (25) ◽  
pp. 11881-11893 ◽  
Author(s):  
Jianglong Mu ◽  
Hui Miao ◽  
Enzhou Liu ◽  
Juan Feng ◽  
Feng Teng ◽  
...  

The novel structure exhibits high-efficiency PEC water splitting performance as a result of enhanced light harvesting, accelerated carrier transportation and effective carrier separation.


2019 ◽  
Vol 25 (11) ◽  
pp. 1249-1264 ◽  
Author(s):  
Amoljit Singh Gill ◽  
Parneet Kaur Deol ◽  
Indu Pal Kaur

Background: Solid free forming (SFF) technique also called additive manufacturing process is immensely popular for biofabrication owing to its high accuracy, precision and reproducibility. Method: SFF techniques like stereolithography, selective laser sintering, fused deposition modeling, extrusion printing, and inkjet printing create three dimension (3D) structures by layer by layer processing of the material. To achieve desirable results, selection of the appropriate technique is an important aspect and it is based on the nature of biomaterial or bioink to be processed. Result & Conclusion: Alginate is a commonly employed bioink in biofabrication process, attributable to its nontoxic, biodegradable and biocompatible nature; low cost; and tendency to form hydrogel under mild conditions. Furthermore, control on its rheological properties like viscosity and shear thinning, makes this natural anionic polymer an appropriate candidate for many of the SFF techniques. It is endeavoured in the present review to highlight the status of alginate as bioink in various SFF techniques.


2013 ◽  
Vol 694-697 ◽  
pp. 497-502
Author(s):  
Jiang Tao Gai ◽  
Shou Dao Huang ◽  
Guang Ming Zhou ◽  
Yi Yuan

In order to search after a new way of the propulsion system of tracked vehicle, a novel structure form of electro-mechanical transmission was developed in this paper, through analyzing the advantages and disadvantages of existing projects of electric drive system for tracked vehicle. It could increase the rate of power exertion obviously and synthesize the mechanical and electrical strongpoint. And based on the structure form, an electro-mechanical transmission was designed with double electromotor added planetary mechanism of steering power coupling and gearshift, considering engineering realization. And then straight-line driving and steering performances of the transmission were calculated which proved that the novel electro-mechanical transmission could meet the requirement of tracked vehicle propulsion well.


Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 488
Author(s):  
Hujun Jia ◽  
Mengyu Dong ◽  
Xiaowei Wang ◽  
Shunwei Zhu ◽  
Yintang Yang

A novel 4H-SiC MESFET was presented, and its direct current (DC), alternating current (AC) characteristics and power added efficiency (PAE) were studied. The novel structure improves the saturation current (Idsat) and transconductance (gm) by adding a heavily doped region, reduces the gate-source capacitance (Cgs) by adding a lightly doped region and improves the breakdown voltage (Vb) by embedding an insulated region (Si3N4). Compared to the double-recessed (DR) structure, the saturation current, the transconductance, the breakdown voltage, the maximum oscillation frequency (fmax), the maximum power added efficiency and the maximum theoretical output power density (Pmax) of the novel structure is increased by 24%, 21%, 9%, 11%, 14% and 34%, respectively. Therefore, the novel structure has excellent performance and has a broader application prospect than the double recessed structure.


2019 ◽  
Vol 1 (1) ◽  
pp. 43-56
Author(s):  
Siti Rukiyah

This study discusses in depth about the moral values of responsibility in the novel Laskar Pelangi. Furthermore, the proposed related to the socio-cultural background of the authors in the creation of novel Laskar Pelangi effect on moral values. In addition, also discussed the author's view of the world related to the teachings of the value of responsibility. This research uses a qualitative approach with content analysis method. The results showed that the value of responsibility based on the novel structure consisting of man's relationship to himself, namely in terms of character and characterization. The characters are displayed Andrea Hirata bring the characters responsible for the thoughts, attitudes, and behavior. From a review of genetic structuralism, the value of responsibility based on social and cultural background, knowledge systems also influence the social and cultural life. Belitung people's livelihood systems are revealed also shape the character responsible. The author's world view of morals includes the value of self-existence, self-esteem, self-confidence, fear, longing, and responsibility.


2014 ◽  
Vol 1064 ◽  
pp. 89-94
Author(s):  
Mohammed Ibrahim Mohamed

In this paper, the novel structure of carbon nanocoils were synthesized successfully by catalytic thermal decomposition of acetylene in CVD reactor under inert atmospheric pressure. Fe as a catalyst coated alumina beads used as substrate , both were placed inside a cylindrical shape stainless steel mesh SSC and located at the mid of CVD reactor. Preliminary study of application of prepared carbon nanocoil in synthesis of photodiode showed that the photodiode has a good rectification and the forward current obeys to tunneling-recombination model.


2021 ◽  
Author(s):  
Danning Fu ◽  
Ruibin Wang ◽  
Rendang Yang

Abstract Cellulose-based composites with superior mechanical and electrical properties are highly desirable for a sustainable and multifunctional substrate of flexible electronics. However, their practical application is hindered by the lack of superflexible cellulose-based composites to fabricate ingenious flexible electronics with considerable robustness. Here, cellulose derived from underutilized biomass (Edgewo-rthia chrysantha Lindi, ERCL) was composited with highly-conductive silver nanowires (AgNWs) through a general papermaking process. Benefiting from the interactions between cellulose and AgNWs including hydrogen bonding and van der Waals force, the composite presented superb electrical conductivity (> 27000 S/m) and flexibility (folding times ≥1110). By employing it as the substrate of flexible pressure sensors (FPSs) through layer-by-layer assembly, improved sensitivity (Gauge Factor=846.4), rapid response (0.44 s), and excellent stability (≥2000 folding cycles) were demonstrated. Impressively, the novel FPS could monitor human motions, including finger bending, elbow flexion, speaking, and pulse, suggesting its great potentials in emerging flexible electronics.


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