Day 1 full schedule
July 08, 2021 @ -
Smart Additive Manufacturing of Ceramic Components with Functional Geometries through Dimensional Modulation in Stereolithographic Technology
In stereolithographic additive manufacturing (STL-AM), 2D cross-sectional patterns were created through photopolymerization by ultraviolet laser drawing on spread resin paste including ceramic nanoparticles, and 3D composite models were sterically printed by layer lamination through chemical bonding. The stereolithography system has been developed to obtain bulky ceramic and metal components with functionally geometric structures. An automatic collimator was newly equipped with the laser scanner to adjust beam diameter. Fine or coarse beams could realize high resolution or wide area drawings, respectively. Nanometer-sized ceramic particles were dispersed into photo-sensitive liquid resins from 40 to 60 % in volume fraction. The paste was spread on a glass substrate at 10 μm in layer thickness. An ultraviolet laser beam of 355 nm in wavelength was adjusted from 10 to 300 μm in variable diameter and scanned on the pasted resin surface. Irradiation power was changed automatically from 10 to 200 mW. The created precursor was dewaxed and sintered in an air atmosphere to obtain full metal or ceramic components. Subsequently, ultraviolet laser lithography was newly developed. 2D cross-sections were created through dewaxing and sintering by UV laser drawing on spread resin paste including ceramic nanoparticles, and 3D composite models were sterically printed by layer laminations. Irradiation power was changed automatically from 1.0 to 1.2 W for enough solidification depth for 2D layer bonding. The half wavelength of the incident ultraviolet ray should be comparable with the nanoparticles gaps in the resin paste, therefore the dewaxing and sintering will be realized through the electromagnetic waves resonations and localizations. Through the smart additive manufacture, design and evaluation (Smart MADE), bioceramic implants of dental crowns were fabricated successfully.
Heli KangasTechnology Manager
Due to ever-increasing awareness of resource sufficiency, climate change mitigation and circularity of materials, many industrial sectors are currently looking for novel solutions in replacing fossil-based materials. Cellulose as a nature-based, sustainable and versatile material is a potential replacement for many synthetic materials. In addition, cellulose has many unique inherent properties that makes it interesting for novel type of applications, beyond the obvious ones, such as paper and board. However, when considering the combination of cellulose and 3D printing, one challenge is painfully obvious: cellulose is not thermoplastic by nature. This challenge is currently being addressed in an EU funded project NOVUM, eventually targeting at building a pilot line suitable for producing components from cellulose-based materials by 3D printing for versatile applications. During the project lifetime, the process will be demonstrated for electrical insulation, marine and automotive industries. For electrical insulation components, cellulose is a common raw material but the state-of-the art production method is rather inefficient in terms of labor, time, energy and waste generation. Additive manufacturing presents an appealing technology for boosting the process. For marine industry, the use case would be something completely new - on-demand printing of outdoor decorative elements for cruise ships. For automotive industry, the key motivation is the increase in sustainability, which the replacement of fossil-based materials with bio-based ones will bring about. The thermoplastic cellulose-based materials developed in the project contain cellulose derivatives, cellulose powders and bio-based plasticizers. They have a higher cellulose content (up to 60%) than the commercial references but the material strength properties are at the same level or even better. The material properties can be tuned according to the requirements of the end use. The materials have excellent printability using commonly available printing technologies such as Fused Deposition Modelling (FDM).
Stereolithographic Additive Manufacturing of Functionally Modulated Components for Environmental Geometries
In stereolithographic additive manufacturing (STL-AM), 2-D cross sections were created through photo polymerization by UV laser drawing on spread resin paste including nanoparticles, and 3-D models were sterically printed by layer lamination. The lithography system has been developed to obtain bulky ceramic components with functional geometries. An automatic collimeter was newly equipped with the laser scanner to adjust beam diameter. Fine or coarse beams could realize high resolution or wide area drawings, respectively. As the row material of the 3-D printing, nanometer sized metal and ceramic particles were dispersed in to acrylic liquid resins at about 60 % in volume fraction. These materials were mixed and deformed to obtained thixotropic slurry. The resin paste was spread on a glass substrate at 50 μm in layer thickness by a mechanically moved knife edge. An ultraviolet laser beam of 355 nm in wavelength was adjusted at 50 μm in variable diameter and scanned on the spread resin surface. Irradiation power was changed automatically for enough solidification depth for layer bonding. The composite precursors including nanoparticles were dewaxed and sintered in the air atmosphere. In recent investigations, ultraviolet laser lithographic additive manufacturing (UVL-AM) was newly developed as a direct forming process of fine metal or ceramic components. As an additive manufacturing technique, 2-D cross sections were created through dewaxing and sintering by UV laser drawing, and 3-D components were sterically printed by layer laminations with interlayer joining. Though the computer aided smart manufacturing, design and evaluation (Smart MADE), practical materials components were fabricated to modulate energy and material transfers in potential fields between human societies and natural environments as active contributions to Sustainable Development to Goals (SDGs).
Pooja ChakrabortyForensic Odontologist
The application can create a permanent record of an object or scene that can be used as demonstrative evidence, preserving the integrity of the actual object or scene. Similarly in Forensic odontology creation of a 3d printed sample will help, keep the original sample intact and all experimental procedures and demonstrations can be carried out on the 3D printed section. In-spite of the limitless application of 3D technologies in the Forensics, it is still sometime before the court of law starts accepting such evidences. This is a comparatively newer area in Forensics and a lot of research is needed before it is given evidentiary value in the judiciary. Over all the advantages, the cost factor is one of the biggest resistance, especially for the developing countries. 3D Scanning and 3D printing requires a huge financial support, which may not be easy for the 3rd World countries to afford.
Subham BanerjeeAssistant Professor
To explore the potential of coupling fused deposition modeling (FDM) mediated 3D printing with hotmelt extrusion (HME) technology to facilitate additive manufacturing to fabricate immediate release (IR) prototypes with the aim of enhanced solubility and fast release properties to formulate IR release tablets. Drugpolymer solubility and interaction parameters were estimated by Hansen solubility parameters, ideal thermal solubility, and Hildebrand-Scott equation. The detailed in-vitro physicochemical evaluations of the developed filament through HME and its derived 3D printed tablet by FDM technique were assessed thoroughly by several analytical means such as light microscopy, DSC, XRD, ATR, SEM, etc. The obtained solubility and interaction parameters values signified drug-polymer miscibility. The average disintegration time of this developed 3D printed IR tablet was found to be 63.33 (±3.6) sec complying with the USP limit. Additionally, in-vitro dissolution study data revealed almost close correlations and both showed 100% of drug release within 15 minutes, thus complying with the definition of IR tablet. Thus, this study demonstrates the feasibility of directly using drugpolymer through the HME process without the addition of any plasticizers, organic solvents, etc. and coupling of HME with 3D printing technology allowing prototypes of IR tablet.
Toward the optimization of 3D printing process using mechanical, thermal, and rheological characteristics of 3D-printed parts
HamidReza VanaeiDoctoral Researcher
Fused filament fabrication, also known as 3D printing, comprises the construction of parts by the deposition of extruded filaments, while moving in successive X-Y planes toward Z direction to fabricate 3D parts layer-by-layer. Since the rheological characteristics such as viscosity are a function of temperature, this dependence believably could be correlated to the temperature evolution of deposited filaments. Beside, to consider the bonding of adjacent filaments, it is important to take into account the temperature evolution at the interface of filaments. To investigate the mechanical, thermal, and rheological characteristics of the 3D-printed parts through the optimization of the process, efforts have been made in employment of very small K-type thermocouples to perform the in-process monitoring of temperature profile of filaments. The obtained results was then embedded into the rheological characteristics of filaments by modeling the viscosity evolution of filaments and the influence of major process variables on it. Moreover, the coalescence criterion was implemented, using the recorded temperature data and temperature dependency viscosity, to predict whether the coalescence/sintering of adjacent filaments for the prediction and optimization of bonding under the mentioned circumstances are adequate. In total, the temperature and viscosity evolution were found to be important in consideration of bonding optimization.
Wei Ling HuangAcupuncturist
Rapid 3D printing on space/air/sea missions, where either gravitational force is missing or severe random disturbance may present continuously, is highly in demand. However, till today, there is no reliable technique for such working environments. The purpose of this study is to develop a technology for rapid 3D printing in solid state of polymeric materials to get rid of the problems in harsh working environment.
The basic concept is to cross-link by either UV-light or photo-induced-heat of polymeric materials in the solid state for rapid 3D printing. The uncross-linked parts can be removed by heating or cooling for melting, or washing away by solvent. Finally, the shape memory effect (SME) of the cross-linked polymers is applied to ensure high accuracy of the printed items.
We have successfully demonstrated this concept using a thermal gel. And we have checked the feasibility of heat-induced cross-linking of a vitrimer polyurethane.