Investigating Approaches to Three-Dimensional Printing of Hydroxyapatite Scaffolds for Bone Regeneration

This study investigated the feasibility of manufacturing hydroxyapatite (HA)-based scaffolds using 3D printing technology by incorporating different binding additives, such as maltodextrin and polyvinyl alcohol (PVOH), into the powder formulation. Different grades of PVOH were evaluated in terms of their impact on the printing quality. Results showed that scaffolds with high architectural accuracy in terms of the design and excellent green compressive strength were obtained when the PVOH (high viscosity) was used as the binding additive for HA.

Mechanical properties of structures 3D printed with cementitious powders

The three dimensional (3D) printing technology has undergone rapid development in the last few years and it is now possible to print engineering structures. This paper presents a study of the mechanical behavior of 3D printed structures using cementitious powder. Microscopic observation reveals that the 3D printed products have a layered orthotropic microstructure, in which each layer consists of parallel strips. Compression and flexural tests were conducted to determine the mechanical properties and failure characteristics of such materials. The test results confirmed that the 3D printed structures are laminated with apparent orthotropy. Based on the experimental results, a stress-strain relationship and a failure criterion based on the maximum stress criterion for orthotropic materials are proposed for the structures of 3D printed material. Finally, a finite element analysis was conducted for a 3D printed shell structure, which shows that the printing direction has a significant influence on the load bearing capacity of the structure.

3D-printed and CNC milled flow-cells for chemiluminescence detection

Herein we explore modern fabrication techniques for the development of chemiluminescence detection flow-cells with features not attainable using the traditional coiled tubing approach. This includes the first 3D-printed chemiluminescence flow-cells, and a milled flow-cell designed to split the analyte stream into two separate detection zones within the same polymer chip. The flow-cells are compared to conventional detection systems using flow injection analysis (FIA) and high performance liquid chromatography (HPLC), with the fast chemiluminescence reactions of an acidic potassium permanganate reagent with morphine and a series of adrenergic phenolic amines.

Impressoras 3D: o direito da propriedade intelectual precisará alcançar novas dimensões?

A presente monografia tem como objeto a análise dos possíveis impactos causados no campo da Propriedade Intelectual oriundos do desenvolvimento da tecnologia de impressão 3D. Este trabalho se estrutura em torno de três grandes seções. A primeira visa à apresentação das impressoras 3D ao leitor, descrevendo um pouco de sua história e, também, suas aplicações. A segunda expõe os principais contornos jurídicos que caracterizam a Propriedade Intelectual e os direitos dela decorrentes, relacionando-os com a impressão 3D. Na última seção, por fim, realiza-se uma reflexão quanto aos desafios apresentados no decorrer do texto e, também, a apresentação de situações que indicam possíveis rumos para a interação entre a tecnologia em questão e a Propriedade Intelectual.

Dos bytes aos átomos: reflexões e experimentações artísticas sobre o universo da impressão 3D

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Um processo para utilizar a tecnologia de impressão 3D na construção de instrumentos didáticos para o ensino de Ciências

Pós-graduação em Educação para a Ciência - FC

Von der Idee bis zum fertigen Produkt - 3D-Drucken mit der PolyJetTM -Technologie von OBJECT

Um mit den immer kürzer werdenden Produkteinführungszeiten Schritt halten zu können, die der harte Wettbewerb heute vorgibt, setzt die produzierende Industrie mehr und mehr auf das 3D-Drucken von Prototypen. Mit dieser Produktionsmethode lassen sich technische Probleme schon in der frühen Entwicklungsphase lösen. Dies spart Kosten und beschleunigt die Entwicklungsschritte. Die innovative PolyJetTM-Technologie von Objet setzt neue Maßstäbe im 3D-Drucken. 
Die Besonderheit: Modelle aus hauchdünnen Materialschichten. So können mit der 
PolyJetTM-Technologie detailgetreue Modelle extrem schnell, einfach und sauber realisiert werden – und das mit hervorragender Oberflächenqualität

3D-Druck von Kunststoff-Medizinprodukten

Das Additive Manufacturing gewinnt im Bereich der Medizintechnik zur Herstellung von Prototypen bis hin zu Endprodukten zunehmend an Bedeutung. Ein großes Hemmnis stellen allerdings die relativ hohen Fertigungskosten dar. Hier bietet der verstärkte Einsatz der 3D-Drucktechnologie (3D Printing) ein erhebliches Potential zur Reduktion der Kosten. Aus dieser Motivation heraus wurde ein 3D-Druckverfahren zur Herstellung biokompatibler, sterilisierbarer Kunststoffmodelle entwickelt. Beim 3D-Druck-Verfahren handelt es sich um einen pulverbasierten Prozess zur schichtweisen Herstellung von Modellen direkt aus Computerdaten. Dabei werden dünne Schichten eines Pulvers auf eine Grundplatte aufgebracht, die dann durch gezielte Binderzugabe entsprechend des aktuellen Bauteilquerschnitts verfestigt werden. Ausgangsmaterial für diesen Prozess ist ein Granulatgemisch auf Basis von PMMA (Polymethylmethacrylat). Als Binderflüssigkeit wird ein Lösungsmittel eingesetzt. Die 3D gedruckten Modelle werden nach einer entsprechenden Trocknungszeit im Pulverbett entpackt und warmgelagert, um das Abdampfen des Lösungsmittels zu beschleunigen. Der Nachweis der Biokompatibilität der hergestellten Modelle erfolgte durch einen Test nach DIN EN ISO 10993-5. In Kooperation mit Anwendern wurden verschiedene Anwendungsbeispiele wie Bohrschablonen, Otoplastiken, Gebissmodelle und Modelle für die präoperative Planung realisiert und charakterisiert.

3D Drucken und die Anwendungen

Eine zunehmende Anzahl von Artikeln in Publikumszeitschriften und Journalen rückt die direkte Herstellung von Bauteilen und Figuren immer mehr in das Bewusstsein einer breiten Öffentlichkeit. Leider ergibt sich nur selten ein einigermaßen vollständiges Bild davon, wie und in welchen Lebensbereichen diese Techniken unseren Alltag verändern werden. Das liegt auch daran, dass die meisten Artikel sehr technisch geprägt sind und sich nur punktuell auf Beispiele stützen. Dieser Beitrag geht von den Bedürfnissen der Menschen aus, wie sie z.B. in der Maslow’schen Bedürfnispyramide strukturiert dargestellt sind und unterstreicht dadurch, dass 3D Printing (oder Additive Manufacturing resp. Rapid Prototyping) bereits alle Lebensbereiche erfasst hat und im Begriff ist, viele davon zu revolutionieren.

La stampante 3D DELTA WASP 3MT - Verso la fabbricazione personale

La tesi segue il progetto della Delta WASP 3MT, stampante 3D di grandi dimensioni. Il lavoro parte da una analisi del contesto che incontra i temi dell'artigianato digitale e dell'autoproduzione. Successivamente viene fatta una analisi dei requisiti e delle soluzioni tecniche implementabili sulla macchina per soddisfarli. A questa segue una illustrazione degli interventi sulle varie parti della macchina. Infine si espongono brevemente i punti chiave elaborati per la comunicazione della macchina, dal naming alla strategia nei punti vendita.

A 3D printed electromagnetic nonlinear vibration energy harvester

A 3D printed electromagnetic vibration energy harvester is presented. The motion of the device is in-plane with the excitation vibrations, and this is enabled through the exploitation of a leaf isosceles trapezoidal flexural pivot topology. This topology is ideally suited for systems requiring restricted out-of-plane motion and benefits from being fabricated monolithically. This is achieved by 3D printing the topology with materials having a low flexural modulus. The presented system has a nonlinear softening spring response, as a result of designed magnetic force interactions. A discussion of fatigue performance is presented and it is suggested that whilst fabricating, the raster of the suspension element is printed perpendicular to the flexural direction and that the experienced stress is as low as possible during operation, to ensure longevity. A demonstrated power of ~25 μW at 0.1 g is achieved and 2.9 mW is demonstrated at 1 g. The corresponding bandwidths reach up-to 4.5 Hz. The system's corresponding power density of ~0.48 mW cm−3 and normalised power integral density of 11.9 kg m−3 (at 1 g) are comparable to other in-plane systems found in the literature.

The Effect of Architecture and Shear Stress on Endothelialization of 3D Printed Vascular Networks

Despite significant progress in the field of tissue engineering within the last decade, a number of unsolved problems still remain. One of the most relevant issues is the lack of proper vascularization that limits the size of engineered tissues to smaller than clinically relevant dimensions. In particular, the growth of engineered tissue in vitro within bioreactors is plagued with this challenge. Specifically, the tubular perfusion system bioreactor has been used for large scale bone constructs; however these engineered constructs lack inherent vasculature and quickly develop a hypoxic core, where no nutrient exchange can occur, thus leading to cell death. Through the use of 3D printed vascular templates in conjunction with a tubular perfusion system bioreactor, we attempt to create an endothelial cell monolayer on 3D scaffolds that could potentially serve as the foundation of inherent vasculature within these engineered bone grafts.

Investigation into the Influence of Build Parameters on Failure of 3D Printed Parts

Additive manufacturing, including fused deposition modeling (FDM), is transforming the built world and engineering education. Deep understanding of parts created through FDM technology has lagged behind its adoption in home, work, and academic environments. Properties of parts created from bulk materials through traditional manufacturing are understood well enough to accurately predict their behavior through analytical models. Unfortunately, Additive Manufacturing (AM) process parameters create anisotropy on a scale that fundamentally affects the part properties. Understanding AM process parameters (implemented by program algorithms called slicers) is necessary to predict part behavior. Investigating algorithms controlling print parameters (slicers) revealed stark differences between the generation of part layers. In this work, tensile testing experiments, including a full factorial design, determined that three key factors, width, thickness, infill density, and their interactions, significantly affect the tensile properties of 3D printed test samples.

3D printed biocompatible enclosures for an implantable DBS microdevice

A number of methods have been used to make electronic medical microdevices biocompatible. This paper presents a novel approach for design and fabrication of biocompatible silicone enclosures for implantable medical microdevices. The approach involves design and formation of a 3D model of the enclosure using a computer-aided design software tool, followed by 3D printing of the enclosures using a bioplotter. Three different implantable enclosure designs are presented. The fabrication of the three enclosures is given. An evaluation of the suitability of the enclosures for implantation of a deep brain stimulation microdevice is discussed through submersion and operation tests. The evaluation results are presented and discussed.

Performance evaluation of 3D printed miniature electromagnetic energy harvesters driven by air flow

As a renewable and non-polluting energy source, wind is used to produce electricity via large-diameter horizontal or vertical axis wind turbines. Such large wind turbines have been well designed and widely applied in industry. However, little attention has been paid to the design and development of miniature wind energy harvesters, which have great potential to be applied to the HVAC (heating, ventilating and air conditions) ventilation exhaust systems and household personal properties. In this work, 10 air-driven electromagnetic energy harvesters are fabricated using 3D printing technology. Parametric measurements are then conducted to study the effects of (1) the blade number, (2) its geometric size, (3) aspect ratio, presence or absence of (4) solid central shaft, (5) end plates, and (6) blade orientation. The maximum electrical power is 0.305 W. To demonstrate its practical application, the electricity generated is used to power 4 LED (light-emitting diode) lights. The maximum overall efficiency ηmax is approximately 6.59%. The cut-in and minimum operating Reynolds numbers are measured. The present study reveals that the 3D printed miniature energy harvesters provide a more efficient platform for harnessing ‘wind power’.