Investigation of future 3D printed brace design parameters: evaluation of mechanical properties and prototype outcomes

2019 ◽  
Vol 3 (4) ◽  
pp. 171-184
Author(s):  
Kenwick JL Ng ◽  
Kajsa Duke ◽  
Edmond Lou
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Treatment Effectiveness ◽  
Design Parameters ◽  
Wear Comfort ◽  
Polypropylene Material ◽  
Spinal Brace ◽  
3D Printed ◽  
Opening And Closing

Aim: Spinal brace wear time affects treatment effectiveness of adolescent idiopathic scoliosis but remains challenging with the brace’s bulkiness. This study aims to determine the appropriate material and thickness to improve wear comfort. Materials & methods: Thirty-one specimens were tested with 13 ULTEM1010 and 13 Nylon12 potential materials and 5 standard polypropylene material in 2.5, 3.25 and 4 mm thicknesses to evaluate mechanical properties. Donning tests of ULTEM1010 and Nylon12 printed braces were conducted. Results: Nylon12 with 2.5–3.25 mm thickness had higher flexibility and the closest mechanical characteristics as 4-mm thick polypropylene. ULTEM1010 brace fractured after 615-times and Nylon12 brace handled 2920-times of opening and closing. Conclusion: Nylon12, 2.5–3.25 mm are appropriate design parameters. Further clinical study can validate long term brace effectiveness.

scholarly journals A Facile Method to Fabricate Anisotropic Extracellular Matrix with 3D Printing Topological Microfibers

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3944 ◽  
Author(s):  
Zhen Gu ◽  
Zili Gao ◽  
Wenli Liu ◽  
Yongqiang Wen ◽  
Qi Gu
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Mechanical Characteristics ◽  
Fiber Direction ◽  
Gelatin Matrix ◽  
Simple Method ◽  
Elongation At Break ◽  
Anisotropic Mechanical Properties ◽  
The Matrix ◽  
3D Printed

Natural tissues and organs have different requirements regarding the mechanical characteristics of response. It is still a challenge to achieve biomaterials with anisotropic mechanical properties using an extracellular matrix with biological activity. We have improved the ductility and modulus of the gelatin matrix using 3D printed gelatin microfibers with different concentrations and topologies and, at the same, time achieved anisotropic mechanical properties. We successfully printed flat microfibers using partially cross-linked gelatin. We modified the 10% (w/v) gelatin matrix with microfibers consisting of a gelatin concentration of 14% (w/v), increasing the modulus to about three times and the elongation at break by 39% in parallel with the fiber direction. At the same time, it is found that the microfiber topology can effectively change the matrix ductility, and changing the modulus of the gelatin used in the microfiber can effectively change the matrix modulus. These findings provide a simple method for obtaining active biological materials that are closer to a physiological environment.

Pemanfaatan Edible Film Dari Limbah Nasi Aking Sebagai Bahan Pelapis Dalam Pengawetan Buah

2021 ◽  
Vol 1 ◽  
pp. 75-79
Author(s):  
Mubarokah N Dewi ◽  
Iqbal Maulana ◽  
Gariza Fadha ◽  
Michelle S Sesira
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Food Additives ◽  
Edible Films ◽  
Edible Film ◽  
Edible Coatings ◽  
Food Ingredients ◽  
Percent Elongation ◽  
Fruit Preservation

The use of synthetic coatings as Food Additives consumed in the long term can damage human health. These horrible effects have paved the way for the development of edible films and natural edible coatings. One of the edible film ingredients is scorched rice which can be used as a coating in fruit preservation. However, the use of this edible film on food ingredients has some problems, especially its mechanical properties which tend to be fragile (not flexible). This article examines the mechanical characteristics of scorched rice with variations in the concentration of glycerol and carrageenan. Based on these results, it was concluded that the higher the volume of glycerol used, the percent elongation increased. The greatest elongation was obtained in the ratio of 3 g of carrageenan with 8 ml of glycerol. However, the addition of glycerol volume causes the biodegradable plastic to tear more easily. The greatest tensile strength value was obtained with a ratio of 5 g of carrageenan and 4 ml of glycerol. The edible film can prevent the spoilage of apples tested for 10 days.

scholarly journals 3D printing of composites: design parameters and flexural performance

2020 ◽  
Vol 26 (4) ◽  
pp. 699-706
Author(s):  
Feras Korkees ◽  
James Allenby ◽  
Peter Dorrington
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Design Parameters ◽  
Content Type ◽  
Flexural Performance ◽  
3D Printed ◽  
Strength And Stiffness

Purpose 3D printing of composites has a high degree of design freedom, which allows for the manufacture of complex shapes that cannot be achieved with conventional manufacturing processes. This paper aims to assess the design variables that might affect the mechanical properties of 3D-printed fibre-reinforced composites. Design/methodology/approach Markforged Mark-Two printers were used to manufacture samples using nylon 6 and carbon fibres. The effect of fibre volume fraction, fibre layer location and fibre orientation has been studied using three-point flexural testing. Findings The flexural strength and stiffness of the 3D-printed composites increased with increasing the fibre volume fraction. The flexural properties were altered by the position of the fibre layers. The highest strength and stiffness were observed with the reinforcement evenly distributed about the neutral axis of the sample. Moreover, unidirectional fibres provided the best flexural performance compared to the other orientations. 3D printed composites also showed various failure modes under bending loads. Originality/value Despite multiple studies available on 3D-printed composites, there does not seem to be a clear understanding and consensus on how the location of the fibre layers can affect the mechanical properties and printing versatility. Therefore, this study covered this design parameter and evaluated different locations in terms of mechanical properties and printing characteristics. This is to draw final conclusions on how 3D printing may be used to manufacture cost-effective, high-quality parts with excellent mechanical performance.

scholarly journals Long-term cyclic use of a sample collector for toilet-based urine analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikail Temirel ◽  
Bekir Yenilmez ◽  
Savas Tasoglu
Keyword(s):  
Health Monitoring ◽  
Urine Analysis ◽  
Geometric Parameters ◽  
Design Parameters ◽  
Sample Collection ◽  
3D Printed ◽  
Continuous Health Monitoring

AbstractUrine analysis via a toilet-based device can enable continuous health monitoring, a transformation away from hospital-based care towards more proactive medicine. To enable reliable sample collection for a toilet-attached analyzer, here a novel sample collector is proposed. The applicability of the proposed sample collector is validated for long-term use. Geometric parameters of the 3D-printed sample collector are optimized. The collected and leftover volumes are quantified for a range of urination speeds and design parameters. For long-term cyclic use, the protein concentrations of samples are quantified and the effectiveness of washing the sample collector is assessed.

scholarly journals Development of Weather-Resistant 3D Printed Structures by Multi-Material Additive Manufacturing

2020 ◽  
Vol 4 (3) ◽  
pp. 94 ◽  
Author(s):  
Arash Afshar ◽  
Roy Wood
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Structural Integrity ◽  
Low Cost ◽  
Acrylonitrile Butadiene Styrene ◽  
Outdoor Environments ◽  
3D Printed ◽  
Novel Method ◽  
Structural Surface

Additive manufacturing, or 3D printing, has had a big impact on the manufacturing world through its low cost, material recyclability, and fabrication of intricate geometries with a high resolution. Three-dimensionally printed polymer structures in aerospace, marine, construction, and automotive industries are usually intended for service in outdoor environments. During long-term exposures to harsh environmental conditions, the mechanical properties of these structures can be degraded significantly. Developing coating systems for 3D printed parts that protect the structural surface against environmental effects and provide desired surface properties is crucial for the long-term integrity of these structures. In this study, a novel method was presented to create 3D printed structures coated with a weather-resistant material in a single manufacturing operation using multi-material additive manufacturing. One group of specimens was 3D printed from acrylonitrile-butadiene-styrene (ABS) material and the other group was printed from ABS and acrylic-styrene-acrylonitrile (ASA) as a substrate and coating material, respectively. The uncoated ABS specimens suffered significant degradation in the mechanical properties, particularly in the failure strain and toughness, during exposure to UV radiation, moisture, and high temperature. However, the ASA coating preserved the mechanical properties and structural integrity of ABS 3D printed structures in aggressive environments.

Mechanical characteristics and surface elemental composition of a Yasargil titanium aneurysm clip after long-term implantation

2010 ◽  
Vol 112 (6) ◽  
pp. 1260-1262 ◽  
Author(s):  
Yasunari Otawara ◽  
Kuniaki Ogasawara ◽  
Hiroshi Kashimura ◽  
Yoshitaka Kubo ◽  
Akira Ogawa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Mechanical Characteristics ◽  
Bending Test ◽  
Corrosion Resistant ◽  
Aneurysm Clip ◽  
Before And After ◽  
Long Time ◽  
And Control

The mechanical properties of titanium-alloy aneurysm clips after long-term implantation in the human cranium are unclear. The characteristics of a Yasargil titanium aneurysm clip were evaluated after long-term implantation for 12 years in a patient with a cerebral aneurysm. The closing forces of the retrieved clip before and after implantation were approximately equal. The bending test showed no differences between the retrieved and control clips. Titanium oxide and calcium were identified on the surface of the retrieved clip, which indicated the formation of corrosion-resistant layers. Titanium-alloy clips retain their mechanical properties in the human cranium for a long time.

Long-Term Creep and Impact Strength of Biocompatible 3D-Printed PLA-Based Scaffolds

2017 ◽  
Vol 13 ◽  
pp. 15-20 ◽  
Author(s):  
Kirill V. Niaza ◽  
Fedor S. Senatov ◽  
Andrey Stepashkin ◽  
Natalia Yu. Anisimova ◽  
Mikhail V. Kiselevsky
Keyword(s):  
Mechanical Properties ◽  
Charpy Impact ◽  
Bone Defects ◽  
Porous Scaffolds ◽  
Fabrication Method ◽  
Fused Filament Fabrication ◽  
3D Printed ◽  
Term Creep ◽  
Small Bone

In the present work porous scaffolds for trabecular bone defects replacement were studied. PLA and PLA/HA сomposites were obtained by extrusion. Scaffolds were obtained by 3D-printing by fused filament fabrication method. Long-term creep and Charpy impact tests show that PLA/HA scaffolds with the maximum force for destruction at impact of 119 N can function under a load of up to 10 MPa without shape changing and loss of mechanical properties. In vivo tests were used to investigate biocompatibility of scaffolds. The scaffolds may be used as implants for unloaded small bone defects replacement

Applying the Hashin–Shtrikman bounds to predict stiffness of multicomponent 3D printed structures: Towards regenerative orthopaedic medicine

2019 ◽  
Vol 54 (16) ◽  
pp. 2173-2183
Author(s):  
Georgio A Katsifis ◽  
David R McKenzie ◽  
Natalka Suchowerska
Keyword(s):  
Mechanical Properties ◽  
Polymer Materials ◽  
Isotropic Composite ◽  
Metallic Implants ◽  
Three Phase ◽  
Implant Size ◽  
3D Printed ◽  
Orthopaedic Medicine ◽  
Lower Limits

Customised orthopaedic implants made from polymer materials would have advantages over metallic implants, if the mechanical properties could be matched more closely to bone. Here, the Hashin–Shtrikman bounds for isotropic composites are used to examine the feasibility of using scaffolds made from 3D printed polyether–etherketone (PEEK) that may adequate modulus immediately after printing, but when integrated and mineralised could approach the modulus of bone. The ability to predict the mechanical properties of 3D printed objects is essential for skeletal implants that require both immediate and long-term strength, such as the mandible and the femur. However, there is no method for predicting the change in mechanical properties due to the effect of ossification of bone scaffolds. Our aim was to calculate the upper and lower limits of the elastic moduli of polymer composites using the Hashin–Shtrikman bounds for isotropic composite solids and use them to compare the pre- and post-ossification properties for a range of scaffolds. We describe 3D printed PEEK as a composite of fully dense PEEK and air, water or bone. We confirm, by mechanically testing three designs, that our 3D printed scaffolds lie within the Hashin–Shtrikman bounds for PEEK–air composites. Improvements in strength achieved by integrating the PEEK scaffold with bone are predicted by calculating the Hashin–Shtrikman bounds for a three-phase composite and show the feasability of reaching bone equivalence. These predictions can be implemented for orthopaedic applications, customising the implant such that it can provide the appropriate immediate and long-term mechanical support for a specific implant size.

Numerical Simulation and Application of Pre-Stress Tubular Pile for the Foundation Pit Engineering

2011 ◽  
Vol 261-263 ◽  
pp. 985-988 ◽  
Author(s):  
Xiang Qiu Wang ◽  
Wen Tian Liu ◽  
Zhi Guo Zhou ◽  
Yu Hong Zhang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Beam Element ◽  
Design Parameters ◽  
Interface Element ◽  
Engineering Practice ◽  
Foundation Pit ◽  
Retaining Structure ◽  
Straight Beam ◽  
Surrounding Soil

Methods of design and technological demands of construction are expounded for the structure with pre-stress tubular pile and anchor in the engineering of foundation pit. The design parameters for the pit are demonstrated by the means of FEM, and its feasibility is proved by the engineering practice. In the model of FEM, some pressure forces are imposed on the middle beam to simulate the anchor’s real mechanical properties. Taking into account the top ring beam and pre-stress tubular pile embedded each other very well, the straight beam element is adopted to simulate mechanical properties both of them. And the non-thickness interface element is also adopted to simulate the mechanical characteristics between the surrounding soil and the retaining structure, These experiences of design have important denotation for other similar foundation pit engineering.

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