scholarly journals User-Tailored Orthosis Design for 3D Printing with PLACTIVE: A Quick Methodology

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 561
Author(s):  
Betsy D. M. Chaparro-Rico ◽  
Katiuscia Martinello ◽  
Sergio Fucile ◽  
Daniele Cafolla
Keyword(s):  
3D Printing ◽  
Experimental Tests ◽  
Extrusion Process ◽  
Additive Concentration ◽  
Expert User ◽  
3D Printed

This paper proposes a methodology for user-tailored orthosis design for 3D printing that aims to give a non-expert, user-oriented tool that easily generates a customized orthosis. Additionally, this work aims to verify the biocompatibility of the PLACTIVE TM (PLACTIVE AN1TM, nano-additive concentration 1%, Copper 3D, Santiago, Chile) filament after extrusion to check its feasibility for 3D printed orthoses. A forefinger and a thumb orthosis were successfully designed applying the proposed methodology. The results showed that the proposed methodology is able to generate simple and practical orthoses through a fairly easy and intuitive procedure. Furthermore, experimental tests showed that the biocompatibility of the PLACTIVE TM filament is not affected after extrusion process, suggesting that it is a feasible material for 3D-printed orthoses.

scholarly journals The Effect of Disinfectants Absorption and Medical Decontamination on the Mechanical Performance of 3D-Printed ABS Parts

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4249
Author(s):  
Diana Popescu ◽  
Florin Baciu ◽  
Catalin Gheorghe Amza ◽  
Cosmin Mihai Cotrut ◽  
Rodica Marinescu
Keyword(s):  
3D Printing ◽  
Medical Devices ◽  
Mechanical Performance ◽  
Acrylonitrile Butadiene Styrene ◽  
Extrusion Process ◽  
Air Gaps ◽  
Safety Issues ◽  
Gas Plasma ◽  
3D Printed ◽  
Butadiene Styrene

Producing parts by 3D printing based on the material extrusion process determines the formation of air gaps within layers even at full infill density, while external pores can appear between adjacent layers making prints permeable. For the 3D-printed medical devices, this open porosity leads to the infiltration of disinfectant solutions and body fluids, which might pose safety issues. In this context, this research purpose is threefold. It investigates which 3D printing parameter settings are able to block or reduce permeation, and it experimentally analyzes if the disinfectants and the medical decontamination procedure degrade the mechanical properties of 3D-printed parts. Then, it studies acetone surface treatment as a solution to avoid disinfectants infiltration. The absorption tests results indicate the necessity of applying post-processing operations for the reusable 3D-printed medical devices as no manufacturing settings can ensure enough protection against fluid intake. However, some parameter settings were proven to enhance the sealing, in this sense the layer thickness being the most important factor. The experimental outcomes also show a decrease in the mechanical performance of 3D-printed ABS (acrylonitrile butadiene styrene) instruments treated by acetone cold vapors and then medical decontaminated (disinfected, cleaned, and sterilized by hydrogen peroxide gas plasma sterilization) in comparison to the control prints. These results should be acknowledged when designing and 3D printing medical instruments.

Exploring 3D printing techniques for the hybrid fabrication of discrete topology optimized structures

2021 ◽  
pp. 147807712110390
Author(s):  
Mauricio Morales-Beltran ◽  
Berk Selamoğlu ◽  
Kaan Çetin ◽  
Halis Arda Özdemir ◽  
Fulya Özbey
Keyword(s):  
3D Printing ◽  
Volume Fraction ◽  
Hybrid Approach ◽  
Experimental Tests ◽  
Discrete Systems ◽  
Optimization Methods ◽  
Hybrid Technique ◽  
Discrete Topology ◽  
Discrete Structures ◽  
3D Printed

The application of topology optimization methods in architecture, while useful for conceptual design explorations, seems to be limited by the practical realization of continuum-type design outcomes. One way to overcome this limitation is setting up design and fabrication techniques, through which continuum domains become discrete structures. This study investigates to which extent discrete optimized systems can be built using a hybrid approach combining 3D printing and analogue fabrication techniques. The procedure is based on an algorithm in Grasshopper (Rhinoceros) that translates continuum topologies obtained in MATLAB into discrete systems, providing alternatives depending on the targeted volume fraction, the intended surface smoothness of the structural components and building material. The study focuses on fabrication aspects and structural performance of discrete structures using 3D printed nodes. Experimental tests evaluate the compressive strength of different types of filaments with varied infill percentages. Final prototypes are fabricated using a hybrid technique involving the use of 3D printed nodes to assemble bar-arrays comprising wooden members. Results provide a critical appraisal of the limitations and potentialities of 3D printing for hybrid fabrication of real scale structures.

3D Printing Miniature Marine Structures Models for Structural Analysis Purpose: Is it Possible?

2019 ◽  
Author(s):  
Miguel Angel Calle Gonzales ◽  
Pentti Kujala
Keyword(s):  
3D Printing ◽  
Scaling Laws ◽  
Experimental Tests ◽  
Additive Manufacture ◽  
Marine Structures ◽  
Thin Walled Structures ◽  
Deformation And Fracture ◽  
Structural Responses ◽  
3D Printed ◽  
The One

Abstract In the last few years, additive manufacture techniques — also known as 3d printing — are gaining more applications in the maritime sector including the production of functional large ship components in compliance with demanded operational and quality standards. By contrast, 3d printing miniature models of marine structures with the aim to reproduce structural responses brings along a higher degree of complexity. On the one hand, miniature thin-walled structures entails different manufacturing challenges when compared with large-size ship components. On the other hand, modeling structural events that comprise extreme reduction scales (around 1:100), material deformation and fracture at high loading rates, among other aspects, require purpose-designed scaling laws to handle all these effects adequately. The aim of this work is to present a wide panorama in the development of miniature 3d printed marine structures aiming to model experimentally ship collision and grounding events in reduced scale. Some preliminary experimental tests in miniature marine structures are also presented.

scholarly journals A methodology for mould conformal cooling channels optimization exploiting 3D printing

2021 ◽  
Author(s):  
Edoardo Battista Arrivabeni ◽  
Daniele Tomasoni ◽  
Luca Giorleo ◽  
Maurizio Claudio Barbato
Keyword(s):  
3D Printing ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Experimental Tests ◽  
Conformal Cooling ◽  
Testing Procedures ◽  
Cooling Channels ◽  
Conformal Cooling Channels ◽  
Push Forward ◽  
3D Printed

With the advent of 3D printing, it is now possible to produce any part or system with an approach than makes design much deeply interlaced with production. In this scenario, CAE has gained power thanks to the possibility of thinking and then manufacture ideas that go well beyond what was possible in the past. This design approach is perfectly suitable to push forward mould conformal cooling performance. In this work, a coupling of CAD, CFD and 3D printing supported by experimental tests was applied to define a design procedure for conformal cooling channels. In particular, cooling channels for a mould were engineered via CAD, then tested via CFD and, after an initial optimization procedure, the chosen design was 3D printed in specimens suitable to be mounted on a heat exchanger (HX) experimental test rig that was especially adapted for the scope. Fluids temperature, volume flow rates and heat transfer performance were measured. A feedback loop was considered to link measurements and channels redesign. Results together with design and testing procedures are reported and commented.

scholarly journals 3D printing of PLA and PMMA multilayered model polymers: an innovative approach for a better-controlled pellet multi-extrusion process

2021 ◽  
Author(s):  
Mohamed Yousfi ◽  
Ahmed Belhadj ◽  
Khalid Lamnawar ◽  
Abderrahim Maazouz
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Processing Parameters ◽  
Extrusion Process ◽  
Thermomechanical Properties ◽  
Three Point Bending ◽  
Short Beam ◽  
Multilayered Systems ◽  
Chamber Temperature ◽  
3D Printed

The present work deals with the 3D printing of multimaterials based on PLA/PMMA multilayers directly obtained from pellets. This polymer pair was chosen for their miscibility at the melt state and synergistic properties (i.e., to improve and weather tune the temperature resistance, transparency and thermomechanical properties of their PLA-based materials). Thus, 3D-printed parts with repeating PMMA/PLA/PMMA layers in the Z building direction were successfully prepared in different numbers but maintaining the same composition. The main objective was to better understand the interface/interphase properties developed during this innovative processing. First, further physicochemical and dynamic thermomechanical characterizations were performed. Second, the effects of multi-extrusion 3D printing processing parameters on the thermal stability of PLA, PMMA and their printed specimens were analyzed by GPC. Then, the structuralrheological and mechanical properties of the multilayered systems were investigated in comparison to their equivalent blend. The effects of flow kinematics during extrusion as well as printing chamber temperature (PCT) and infill density (ID) were specifically studied and rationalized. The triggered interfaces were characterized by SEM and subjected to flexural and short-beam three-point bending experiments that proved their dramatic influence on the final mechanical properties. The ultimate aim of this study is to enable successful control of the interfaces/interphases obtained in these 3D-printed PLA/PMMA systems in comparison to other forming processes.

Biodegradable 3D Printed Polymer Microneedles for Transdermal Drug Delivery

2018 ◽  
Author(s):  
Michael A. Luzuriaga ◽  
Danielle R. Berry ◽  
John C. Reagan ◽  
Ronald A. Smaldone ◽  
Jeremiah J. Gassensmith
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Transdermal Drug Delivery ◽  
Fused Deposition Modeling ◽  
Fused Deposition ◽  
Modeling Software ◽  
Deposition Modeling ◽  
3D Printed ◽  
Microfabrication Technique ◽  
Mechanical Strengths

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.

Biomimetic Design of 3D Printed Tissue-engineered bone Constructs

2020 ◽  
Vol 16 ◽  
Author(s):  
Wei Liu ◽  
Shifeng Liu ◽  
Yunzhe Li ◽  
Peng Zhou ◽  
Qian ma
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Advanced Materials ◽  
Bionic Design ◽  
Material Interfaces ◽  
Precise Control ◽  
Cell Printing ◽  
Biomimetic Scaffolds ◽  
3D Printed

Abstract:: Surgery to repair damaged tissue, which is caused by disease or trauma, is being carried out all the time, and a desirable treatment is compelling need to regenerate damaged tissues to further improve the quality of human health. Therefore, more and more research focus on exploring the most suitable bionic design to enrich available treatment methods. 3D-printing, as an advanced materials processing approach, holds promising potential to create prototypes with complex constructs that could reproduce primitive tissues and organs as much as possible or provide appropriate cell-material interfaces. In a sense, 3D printing promises to bridge between tissue engineering and bionic design, which can provide an unprecedented personalized recapitulation with biomimetic function under the precise control of the composition and spatial distribution of cells and biomaterials. This article describes recent progress in 3D bionic design and the potential application prospect of 3D printing regenerative medicine including 3D printing biomimetic scaffolds and 3D cell printing in tissue engineering.

scholarly journals Design of a 3D-printed hand prosthesis featuring articulated bio-inspired fingers

2020 ◽  
pp. 095441192098088
Author(s):  
Juan Sebastian Cuellar ◽  
Dick Plettenburg ◽  
Amir A Zadpoor ◽  
Paul Breedveld ◽  
Gerwin Smit
Keyword(s):  
3D Printing ◽  
Design Principles ◽  
Prosthetic Hand ◽  
Hand Prosthesis ◽  
Fused Deposition ◽  
Pinch Force ◽  
Actuation System ◽  
3D Printed ◽  
Energy Dissipated ◽  
Dual Material

Various upper-limb prostheses have been designed for 3D printing but only a few of them are based on bio-inspired design principles and many anatomical details are not typically incorporated even though 3D printing offers advantages that facilitate the application of such design principles. We therefore aimed to apply a bio-inspired approach to the design and fabrication of articulated fingers for a new type of 3D printed hand prosthesis that is body-powered and complies with basic user requirements. We first studied the biological structure of human fingers and their movement control mechanisms in order to devise the transmission and actuation system. A number of working principles were established and various simplifications were made to fabricate the hand prosthesis using a fused deposition modelling (FDM) 3D printer with dual material extrusion. We then evaluated the mechanical performance of the prosthetic device by measuring its ability to exert pinch forces and the energy dissipated during each operational cycle. We fabricated our prototypes using three polymeric materials including PLA, TPU, and Nylon. The total weight of the prosthesis was 92 g with a total material cost of 12 US dollars. The energy dissipated during each cycle was 0.380 Nm with a pinch force of ≈16 N corresponding to an input force of 100 N. The hand is actuated by a conventional pulling cable used in BP prostheses. It is connected to a shoulder strap at one end and to the coupling of the whiffle tree mechanism at the other end. The whiffle tree mechanism distributes the force to the four tendons, which bend all fingers simultaneously when pulled. The design described in this manuscript demonstrates several bio-inspired design features and is capable of performing different grasping patterns due to the adaptive grasping provided by the articulated fingers. The pinch force obtained is superior to other fully 3D printed body-powered hand prostheses, but still below that of conventional body powered hand prostheses. We present a 3D printed bio-inspired prosthetic hand that is body-powered and includes all of the following characteristics: adaptive grasping, articulated fingers, and minimized post-printing assembly. Additionally, the low cost and low weight make this prosthetic hand a worthy option mainly in locations where state-of-the-art prosthetic workshops are absent.

3D-printed Futures of Manufacturing, Social Change and Technological Innovation in China and Singapore: The Ghost of a Massless Future?

2019 ◽  
Vol 24 (2) ◽  
pp. 254-270 ◽  
Author(s):  
Luke Heemsbergen ◽  
Angela Daly ◽  
Jiajie Lu ◽  
Thomas Birtchnell
Keyword(s):  
Social Change ◽  
3D Printing ◽  
Technological Innovation ◽  
First Century ◽  
Global Knowledge ◽  
Law And Technology ◽  
3D Printed ◽  
Twenty First Century ◽  
Political Economic

This article outlines preliminary findings from a futures forecasting exercise where participants in Shenzhen and Singapore considered the socio-technological construction of 3D printing in terms of work and social change. We offered participants ideal political-economic futures across local–global knowledge and capital–commons dimensions, and then had them backcast the contextual waypoints across markets, culture, policy, law and technology dimensions that help guide towards each future. Their discussion identified various contextually sensitive points, but also tended to dismiss the farthest reaches of each proposed ideal, often reverting to familiar contextual signifiers. Here, we offer discussion on how participants saw culture and industry shaping futures for pertinent political economic concerns in the twenty-first century.

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