scholarly journals 3D printing orthopedic scoliosis braces: a test comparing FDM with thermoforming

2020 ◽  
Vol 111 (5-6) ◽  
pp. 1707-1720
Author(s):  
Davide Felice Redaelli ◽  
Valentina Abbate ◽  
Fabio Alexander Storm ◽  
Alfredo Ronca ◽  
Andrea Sorrentino ◽  
...  

Abstract In recent years, 3D printing gained considerable attention in the orthopedic sector. This work evaluates the feasibility of producing orthopedic scoliosis braces by 3D printing, comparing performance and costs with classical thermoforming procedures. Critical parameters, such as manufacture time, mechanical properties, weight, and comfort are carefully considered. Polyethylene terephthalate glycol-modified (PETG) was selected among the several filaments materials present on the market. Printed samples were analyzed with electronic microscope, tensile, and impact tests and compared with thermoformed polyethylene (PE) and polypropylene (PP) samples. Moreover, a cost analysis was carried out for the specific application. The thermoformed brace of a volunteer patient affected by scoliosis was reproduced using reverse-engineering techniques. The model was then printed as a single piece and postprocessed by an expert orthotist. Subsequently, the patient wore the brace in a pilot case to compare comfort and mechanical effectiveness. Results show that the 3D printing fabrication method is able to provide a valid alternative to the current fabrication methods, being also very competitive in terms of costs. The morphological analysis does not show critical defects in 3D printed samples, while the mechanical tests highlighted their anisotropy, with an overall brittleness of PETG samples in the direction orthogonal to the fibers. However, in terms of mechanical stresses, a back brace should never reach the polymer yield stress, otherwise the shape would be modified and the therapeutic effect could be compromised. Finally, the patient reported the perception of improved support and no significant comfort differences compared with the thermoformed brace.

2020 ◽  
Vol 13 (1) ◽  
pp. 45-65 ◽  
Author(s):  
Anna V. Nielsen ◽  
Michael J. Beauchamp ◽  
Gregory P. Nordin ◽  
Adam T. Woolley

Traditional microfabrication techniques suffer from several disadvantages, including the inability to create truly three-dimensional (3D) architectures, expensive and time-consuming processes when changing device designs, and difficulty in transitioning from prototyping fabrication to bulk manufacturing. 3D printing is an emerging technique that could overcome these disadvantages. While most 3D printed fluidic devices and features to date have been on the millifluidic size scale, some truly microfluidic devices have been shown. Currently, stereolithography is the most promising approach for routine creation of microfluidic structures, but several approaches under development also have potential. Microfluidic 3D printing is still in an early stage, similar to where polydimethylsiloxane was two decades ago. With additional work to advance printer hardware and software control, expand and improve resin and printing material selections, and realize additional applications for 3D printed devices, we foresee 3D printing becoming the dominant microfluidic fabrication method.


2021 ◽  
Author(s):  
Hannah B. Musgrove ◽  
Megan A. Catterton ◽  
Rebecca R. Pompano

Stereolithographic (SL) 3D printing, especially digital light processing (DLP) printing, is a promising rapid fabrication method for bio-microfluidic applications such as clinical tests, lab-on-a-chip devices, and sensor integrated devices. The benefits of 3D printing lead many to believe this fabrication method will accelerate the use of bioanalytical microfluidics, but there are major obstacles to overcome to fully utilize this technology. For commercially available printing materials, this includes challenges in producing prints with the print resolution and mechanical stability required for a particular design, along with cytotoxic components within many SL resins and low optical compatibility for imaging experiments. Potential solutions to these problems are scattered throughout the literature and rarely available in head-to-head comparisons. Therefore, we present here principles for navigation of 3D printing techniques and systematic tests to inform resin selection and optimization of the design and fabrication of SL 3D printed bio-microfluidic devices.


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2037
Author(s):  
Guangxue Chen ◽  
Xiaochun Wang ◽  
Haozhi Chen ◽  
Chen Chen

The powder-based 3DP (3D printing) technique has developed rapidly in creative and customized industries on account of it’s uniqueness, such as low energy consumption, cheap consumables, and non-existent exhaust emissions. Moreover, it could actualize full-color 3D printing. However, the printing time and size are both in need of upgrade using ready printers, especially for large-size 3D printing objects. Given the above issues, the effects of height and monolayer area on printing time were explored and the quantitative relationship was given in this paper conducted on the specimens with a certain gradient. On this basis, an XYX rotation method was proposed to minimize the printing time. The mechanical tests were conducted with three impregnation types as well as seven printing angles and combined with the characterization of surface structure based on the scanning electron microscope (SEM) digital images to explore the optimum parameters of cutting-bonding frame (CBF) applied to powder-based 3D printing. Then, four adhesives were compared in terms of the width of bonded gap and chromatic aberration. The results revealed that ColorBond impregnated specimens showed excellent mechanical properties which reached maximum when printed at 45° to Z axis, and α-cyanoacrylate is the most suitable adhesive to bond full-color powder-based models. Finally, an operation technological process was summarized to realize the rapid manufacturing of large-size full-color 3D printed objects.


Author(s):  
Zhe Chen ◽  
Xiaohong Sun ◽  
Yunpeng Shang ◽  
Kunzhou Xiong ◽  
Zhongkai Xu ◽  
...  

AbstractThree-dimensional (3D) printing technology is becoming a promising method for fabricating highly complex ceramics owing to the arbitrary design and the infinite combination of materials. Insufficient density is one of the main problems with 3D printed ceramics, but concentrated descriptions of making dense ceramics are scarce. This review specifically introduces the principles of the four 3D printing technologies and focuses on the parameters of each technology that affect the densification of 3D printed ceramics, such as the performance of raw materials and the interaction between energy and materials. The technical challenges and suggestions about how to achieve higher ceramic density are presented subsequently. The goal of the presented work is to comprehend the roles of critical parameters in the subsequent 3D printing process to prepare dense ceramics that can meet the practical applications.


Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 298 ◽  
Author(s):  
Zeraatkar ◽  
Filippini ◽  
Percoco

A wide variety of 3D printing technologies have been used for the fabrication of lab-on-a-chip (LOC) devices in recent years. Despite the large number of studies having examined the use of 3D printing technologies in microfluidic devices, the effect of the fabrication method on their performance has received little attention. In this paper, a comparison is shown between unibody-LOC micro-mixers, a particular type of monolithic design for 3D printed LOCs, fabricated in polyjet, stereolithography (SLA) and fused deposition modelling (FDM or FFF) platforms, paying particular attention to the inherent limitations of each fabrication platform and how these affect the performance of the manufactured devices.


2017 ◽  
Vol 2 (2) ◽  
pp. 135 ◽  
Author(s):  
Angus P Fitzpatrick

<p>3D printing is a manufacturing technique by which the material is added layer by layer to create a physical three-dimensional object. This manufacturing technique had primarily found uses in academic and commercial sectors for prototyping and product realization purposes. However, more recently the home consumer market has seen a surge in low cost printers bringing this capability to the masses. More recently 3D printing has seen considerable interest from the clinical sector, where alongside the synergistic use with medical imaging data, a whole generation of patient specific implantable technologies, splints/casts and resection guides can be created. Predominantly, clinical applications have focused on the use of 3D printing for bone replacement, however with the advent of more sophisticated multi-material printers, interest has now begun to move to applications in orthotics and orthopedic casting.</p><p>This study is to review and evaluate the feasibility of designing and realizing a more patient specific orthopedic cast to surpass current limitation with traditional fiberglass/plaster casts, through the use of advanced 3D modelling and printing techniques. To directly compare the efficacy of the traditional and 3D printed casts, we shall investigate critical parameters such as the time for manufacture, the overall weight of the final product, the accuracy off the cast relative to the patient’s unique anatomy and additional user-centric metrics (comfort, aesthetics, etc.). The design examined made use of advanced mesh structures throughout the bulk of the cast, such that the device would require less material (by weight) during fabrication, could allow for tunable weight and mechanical properties and allow for air penetration to the person skin, thereby reducing discomfort due to prolonged moisture exposure (chaffing, bad smells, etc.). As the primary focus of this study is the design and product realization phases and we shall not assess metrics relating to patient recover time or experience.</p><p>Overall it was found that the 3D printed cast was significantly lighter, with improved water repellent and air circulation properties, as compared to a traditional cast. Through the use of high precision design/manufacturing techniques, the final device could be accurately reproduced to match the test patient’s unique anatomy, thereby optimizing the orientation of the patient’s bones during post fracture recovery. It was however found that the manufacturing time for the 3D printed cast was slower than traditional casting methods owing to the additional time during the design phase. In future work we aim to address this limitation and to devise a streamlined methodology such that a generic cast design can be adapted to patient specific anatomical data through parametric design algorithms.</p><p>Ultimately, it was found that through the use of advanced design techniques, patient specific data and 3D printing, a custom orthopedic cast could be realized and with significant potential to augment current use of this technology for surgical intervention and improve patient outcomes. The use of advanced manufacturing in the medical field will likely enable more patient specific/user-centric treatment in the near future.</p>


2021 ◽  
Vol 1025 ◽  
pp. 47-52
Author(s):  
Denesh Mohan ◽  
Mohd Shaiful Sajab ◽  
Saiful Bahari Bakarudin ◽  
Rasidi Bin Roslan ◽  
Hatika Kaco

3D printing allows industries to scale the development from rapid prototyping to mass production in an easier manner. However, a typical photopolymers resin for stereolithography 3D printing possesses lower mechanical properties which incapable to meet certain industrial requirements for high impact applications. Hence, 0.1 to 2.0 wt.% of graphene nanoplatelets (GnP) were incorporated into photo-curable polyurethane (PU) based resin through digital light processing (DLP) 3D printing to evaluate its reinforcement effect. FTIR spectrum proves that significant characteristics of PU were still dominant upon the addition of GnP, indicating there was no chemical interaction between PU and GnP. The interfacial adhesion and the homogeneity of GnP in PU matrix were investigated through morphological analysis and the strength and stiffness of the 3D-printed composites. Results shows, tensile strength and Young’s Modulus of the PU/1%GnP composite had an increment of 21% and 24%, respectively when compared to neat PU resin. However, further increment of GnP reduced the mechanical properties because of interruption in UV curing during printing, hence leading to interfacial voids and defects on the printed specimens.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 727
Author(s):  
Rebeca Leu Alexa ◽  
Horia Iovu ◽  
Jana Ghitman ◽  
Andrada Serafim ◽  
Cristina Stavarache ◽  
...  

The development of materials for 3D printing adapted for tissue engineering represents one of the main concerns nowadays. Our aim was to obtain suitable 3D-printed scaffolds based on methacrylated gelatin (GelMA). In this respect, three degrees of GelMA methacrylation, three different concentrations of GelMA (10%, 20%, and 30%), and also two concentrations of photoinitiator (I-2959) (0.5% and 1%) were explored to develop proper GelMA hydrogel ink formulations to be used in the 3D printing process. Afterward, all these GelMA hydrogel-based inks/3D-printed scaffolds were characterized structurally, mechanically, and morphologically. The presence of methacryloyl groups bounded to the surface of GelMA was confirmed by FTIR and 1H-NMR analyses. The methacrylation degree influenced the value of the isoelectric point that decreased with the GelMA methacrylation degree. A greater concentration of photoinitiator influenced the hydrophilicity of the polymer as proved using contact angle and swelling studies because of the new bonds resulting after the photocrosslinking stage. According to the mechanical tests, better mechanical properties were obtained in the presence of the 1% initiator. Circular dichroism analyses demonstrated that the secondary structure of gelatin remained unaffected during the methacrylation process, thus being suitable for biological applications.


Author(s):  
Michael A. Luzuriaga ◽  
Danielle R. Berry ◽  
John C. Reagan ◽  
Ronald A. Smaldone ◽  
Jeremiah J. Gassensmith

Biodegradable polymer microneedle (MN) arrays are an emerging class of transdermal drug delivery devices that promise a painless and sanitary alternative to syringes; however, prototyping bespoke needle architectures is expensive and requires production of new master templates. Here, we present a new microfabrication technique for MNs using fused deposition modeling (FDM) 3D printing using polylactic acid, an FDA approved, renewable, biodegradable, thermoplastic material. We show how this natural degradability can be exploited to overcome a key challenge of FDM 3D printing, in particular the low resolution of these printers. We improved the feature size of the printed parts significantly by developing a post fabrication chemical etching protocol, which allowed us to access tip sizes as small as 1 μm. With 3D modeling software, various MN shapes were designed and printed rapidly with custom needle density, length, and shape. Scanning electron microscopy confirmed that our method resulted in needle tip sizes in the range of 1 – 55 µm, which could successfully penetrate and break off into porcine skin. We have also shown that these MNs have comparable mechanical strengths to currently fabricated MNs and we further demonstrated how the swellability of PLA can be exploited to load small molecule drugs and how its degradability in skin can release those small molecules over time.


Author(s):  
Y. R. Kim ◽  
S. W. Lee ◽  
J. H. Kim ◽  
J. W. Kwon ◽  
S. K. Lee

Sign in / Sign up

Export Citation Format

Share Document