Replicating the Kinora: 3D Modelling and Printing as Heuristics in Digital Media History

Computer development (2022)

The Kinora replica 3D model was produced in the context of the project "Doing Experimental Media Archaeology: Practice and Theory (DEMA)", funded by the Fonds National de la Recherche, Luxembourg (FNR ... [more ▼]

The Kinora replica 3D model was produced in the context of the project "Doing Experimental Media Archaeology: Practice and Theory (DEMA)", funded by the Fonds National de la Recherche, Luxembourg (FNR) (C18/SC/12703137): https://dema.uni.lu/. The Kinora replica project was the result of a collaboration between the Luxembourg Centre for Contemporary and Digital History (C2DH) and the Department of Engineering (DoE) of the University of Luxembourg. See for more information the article "Replicating the Kinora: 3D modelling and printing as heuristics in digital media history", published in the Journal of Digital History: https://journalofdigitalhistory.org/en/article/33pRxE2dtUHP [less ▲]

Practical Implementation of Functionally Graded Lattice Structures in a Bicycle Crank Arm

in 850th International Conference on Science, Technology, Engineering and Management (2020, November 25)

Functionally graded lattice structures (FGLS) were studied thoroughly for the past years, mostly focusing on specific synthetic tests in the context of additive manufacturing while rarely being actually ... [more ▼]

Functionally graded lattice structures (FGLS) were studied thoroughly for the past years, mostly focusing on specific synthetic tests in the context of additive manufacturing while rarely being actually applied outside of this specific domain. This paper examines a way to practically implement them in a commonly used appliance and study their potential for its improvement. A bicycle crank arm was chosen for this purpose, and a solid aluminium reference model (Shimano FC-R450-453) is used as a performance baseline. The novel design is composed of a hollow body containing a beam-based, non-stochastic, functionally graded lattice structure and is planned to be manufactured on a Markforged Metal X system using 17-4 PH stainless steel. It aims to increase the total stiffness under EN ISO 4210-8 norm loading conditions compared to the reference model while limiting mass and stress values to acceptable degrees. Two crank arm variants, containing a face-centred cubic (FCC) and re-entrant auxetic lattice respectively, are optimised by locally altering their beam radii in eight separate regions. The displacement at the load application point is minimised using Altair OptiStruct and HyperStudy. The reference crank, weighing 213g, exhibits a deflection magnitude of 7.1mm in the most demanding load case while the newly designed and optimised versions only showed displacements of 2.52mm (FCC lattice, 340g) and 2.58mm (re-entrant lattice, 339g) respectively. In addition, the stress distribution was significantly enhanced compared to the reference model, as the latter would not pass the fatigue tests required by the norm. This demonstrates that FGLS, in combination with high-strength materials and additive manufacturing, can increase the performance of many parts, although in this case, with a trade-off in terms of its mass. In future projects, it might be considerably reduced by utilising alternative lattice types lattices or other materials while preserving the benefits of FGLS. [less ▲]

Upcycling polymers: a revolutionary approach to promoting the circular economy

in Impact (2018), 2018(Number 9), 103-1053

The UPcycling using Additive Manufacturing (UpAM) project seeks to introduce an innovative educational and interactive framework to demonstrate the benefits of upcycling so that any individual can produce ... [more ▼]

The UPcycling using Additive Manufacturing (UpAM) project seeks to introduce an innovative educational and interactive framework to demonstrate the benefits of upcycling so that any individual can produce their own products using recycled raw materials. For years, societies have been aware that the unlimited consumption of products is unavoidably intertwined with the unlimited production of waste. This is exactly why scientists and researchers have been trying to find alternative and meaningful solutions to the Linear Economy model, a model that dictates a specific sequence of events: extracting raw materials, manufacturing products, consuming and discarding these products. Looking beyond that ‘take, make, dispose’ approach, it was in 1989 that the notion of Circular Economy (CE) was first proposed by Pearce and Turner; a concept that is restorative and regenerative and that involves reusing products, repairing, recycling and upcycling. Therefore, the core element of this innovative and environmentally-friendly model is to rely on system-wide innovative processes in order to redefine products, services and, most importantly, our way of thinking, to design waste out, thus allowing a profound transition to renewable energy sources [less ▲]

Numerical comparative study of five currently used implants for high tibial osteotomy: realistic loading including muscle forces versus simplified experimental loading

in Journal of Experimental Orthopaedics (2017), 5(28),

Background Many different fixation devices are used to maintain the correction angle after medial open wedge high tibial osteotomy (MOWHTO). Each device must provide at least sufficient mechanical ... [more ▼]

Background Many different fixation devices are used to maintain the correction angle after medial open wedge high tibial osteotomy (MOWHTO). Each device must provide at least sufficient mechanical stability to avoid loss of correction and unwanted fracture of the contralateral cortex until the bone heals. In the present study, the mechanical stability of following different implants was compared: the TomoFix small stature (sm), the TomoFix standard (std), the Contour Lock, the iBalance and the second generation PEEKPower. Simplified loading, usually consisting of a vertical load applied to the tibia plateau, is used for experimental testing of fixation devices and also in numerical studies. Therefore, this study additionally compared this simplified experimental loading with a more realistic loading that includes the muscle forces. Method Two types of finite element models, according to the considered loading, were created. The first type numerically simulated the static tests of MOWHTO implants performed in a previous experimental biomechanical study, by applying a vertical compressive load perpendicularly to the plateau of the osteotomized tibia. The second type included muscle forces in finite element models of the lower limb with osteotomized tibiae and simulated the stance phase of normal gait. Section forces in the models were determined and compared. Stresses in the implants and contralateral cortex, and micromovements of the osteotomy wedge, were calculated. Results For both loading types, the stresses in the implants were lower than the threshold values defined by the material strength. The stresses in the lateral cortex were smaller than the ultimate tensile strength of the cortical bone. The implants iBalance and Contour Lock allowed the smallest micromovements of the wedge, while the PEEKPower allowed the highest. There was a correlation between the micromovements of the wedge, obtained for the simplified loading of the tibia, and the more realistic loading of the lower limb at 15% of the gait cycle (Pearson’s value r = 0.982). Conclusions An axial compressive load applied perpendicularly to the tibia plateau, with a magnitude equal to the first peak value of the knee joint contact forces, corresponds quite well to a realistic loading of the tibia during the stance phase of normal gait (at 15% of the gait cycle and a knee flexion of about 22 degrees). However, this magnitude of the knee joint contact forces overloads the tibia compared to more realistic calculations, where the muscle forces are considered. The iBalance and Contour Lock implants provide higher rigidity to the bone-implant constructs compared to the TomoFix and the PEEKPower plates. [less ▲]

UpAM: UPCYCLING VIA ADDITIVE MANUFACTURING – HOW 3D PRINTING CAN ENHANCE CIRCULAR ECONOMY

in REVUE TECHNIQUE LUXEMBOURGEOISE (2017), 2017(2), 38

The University of Luxembourg developed the project upAM upcycling using Additive Manufacturing with the cooperation of FabLab Belval and Luxinnovation. This project was partially financed by Luxembourg ... [more ▼]

The University of Luxembourg developed the project upAM upcycling using Additive Manufacturing with the cooperation of FabLab Belval and Luxinnovation. This project was partially financed by Luxembourg National Research Fund Luxembourg (FNR). An alternative to a linear economy: extracting raw materials, producing, consuming, and discarding of a product, there is another option: Circular Economy (CE): reusing products, repairing, recycling, and upcycling. A concept of a system/process (upAM) is developed to reuse unwanted or un-functional polymers issued from existing products/ systems. Waste prints can be re-printed into new products or systems with the same / higher quality or value than products created from raw materials. The upAM project is, therefore, concentrating on upcycling according to the definition given by author” Upcycling is a process in which used materials are converted into something of a higher value and/or quality in their second life”. This definition is simple and reflects fully the meaning of the upcycling process. This idea is not new; the concept of reused materials/products giving them a new life has been present for hundreds of years as a countermeasure against the lack of raw materials. At the moment, the situation in developed countries is evolving. Society is more aware that unlimited consumption leads to unlimited production of waste. Therefore, collective consciousness of a circular economy occurs, which supports greater resources of productivity aiming to reduce waste and avoid pollution by design, and purposeful reused waste materials and unwanted products. Upcycling via additive manufacturing could be an important part of the circular economy (CE). Obviously, the CE and especially the upcycling process lead to reducing the usage of new raw materials, and it results in a reduction of energy usage, air and water pollution and even greenhouse gas emissions. The development of maker movement and democratisation of FDM technology is also strongly influencing the needs and benefits of the upcycling process. The project upAM is developed to increase this idea so that any individual can produce their products with a higher added value using recycled raw materials via the open technology of FDM 3D Printer. [less ▲]