Beyond developable: computational design and fabrication with auxetic materials

We present a computational method for interactive 3D design and rationalization of surfaces via auxetic materials, i.e., flat flexible material that can stretch uniformly up to a certain extent. A key motivation for studying such material is that one can approximate doubly-curved surfaces (such as the sphere) using only flat pieces, making it attractive for fabrication. We physically realize surfaces by introducing cuts into approximately inextensible material such as sheet metal, plastic, or leather. The cutting pattern is modeled as a regular triangular linkage that yields hexagonal openings of spatially-varying radius when stretched. In the same way that isometry is fundamental to modeling developable surfaces, we leverage conformal geometry to understand auxetic design. In particular, we compute a global conformal map with bounded scale factor to initialize an otherwise intractable non-linear optimization. We demonstrate that this global approach can handle non-trivial topology and non-local dependencies inherent in auxetic material. Design studies and physical prototypes are used to illustrate a wide range of possible applications

Raising new opportunities for the Next Economy by exploring variable user needs for Computational Co-Design

Digital Fabrication promises to revolutionize manufacturing, bringing both economic, social and environmental benefits. Combined with Computational CoDesign it can raise the creative potential of both designers and users. However, today the productive use of Digital Fabrication and Computational Design requires significant effort and specialised know-how, so valorising these practices calls for the identification of the application fields that benefit the most from them. This paper presents a tool for helping the discovery of design opportunities across comprehensive, ramified lists of product categories, where designers can identify possible points of intervention. The web-based tool allows the rapid evaluation of numerous product categories according to an extendable set of factors and inspiring questions related to the necessity of personalization, aiming to stimulate designers to consider unexpected frontiers of innovation. Beyond the scope of the research project, this tool has the potential to assist designers in finding applications also for other emerging technologies in a structured and scalable wa

Transferring Unit Cell Based Tissue Scaffold Design to Solid Freeform Fabrication

Designing for the freeform fabrication of heterogeneous tissue scaffold is always a challenge in Computer Aided Tissue Engineering. The difficulties stem from two major sources: 1) limitations in current CAD systems to assembly unit cells as building blocks to form complex tissue scaffolds, and 2) the inability to generate tool paths for freeform fabrication of unit cell assemblies. To overcome these difficulties, we have developed an abstract model based on skeletal representation and associated computational methods to assemble unit cells into an optimized structure. Additionally we have developed a process planning technique based on internal architecture pattern of unit cells to generate tool paths for freeform fabrication of tissue scaffold. By modifying our optimization process, we are able to transfer an optimized design to our fabrication system via our process planning technique.Mechanical Engineerin

Proceedings of the 2021 DigitalFUTURES

This open access book is a compilation of selected papers from 2021 DigitalFUTURES—The 3rd International Conference on Computational Design and Robotic Fabrication (CDRF 2021). The work focuses on novel techniques for computational design and robotic fabrication. The contents make valuable contributions to academic researchers, designers, and engineers in the industry. As well, readers encounter new ideas about understanding material intelligence in architecture

Computational Capacity and Energy Consumption of Complex Resistive Switch Networks

Resistive switches are a class of emerging nanoelectronics devices that exhibit a wide variety of switching characteristics closely resembling behaviors of biological synapses. Assembled into random networks, such resistive switches produce emerging behaviors far more complex than that of individual devices. This was previously demonstrated in simulations that exploit information processing within these random networks to solve tasks that require nonlinear computation as well as memory. Physical assemblies of such networks manifest complex spatial structures and basic processing capabilities often related to biologically-inspired computing. We model and simulate random resistive switch networks and analyze their computational capacities. We provide a detailed discussion of the relevant design parameters and establish the link to the physical assemblies by relating the modeling parameters to physical parameters. More globally connected networks and an increased network switching activity are means to increase the computational capacity linearly at the expense of exponentially growing energy consumption. We discuss a new modular approach that exhibits higher computational capacities and energy consumption growing linearly with the number of networks used. The results show how to optimize the trade-off between computational capacity and energy efficiency and are relevant for the design and fabrication of novel computing architectures that harness random assemblies of emerging nanodevices

Parametric Design Optimization and Robotic Fabrication of Joints forIrregular Grid-based Structure

This paper describes the abilities of parametric iterative design with collaboration of robotic fabrication workflow in structural optimization of the nodes (joints) of special grid-based structure. Experimental structure built in robotic fabrication workshop – (the Dynamo-BUILD workshop at the 2016 International Conference on Robotic Fabrication in Architecture, Art, and Design Conference in Sydney, Australia) - is taken as a case study. In this study, the complexity of structure form combined of joints and members is resolved and developed through parametric design algorithms. Focusing on joints, the case gives workflow structure methods of design and fabrication that transfer the level of mass simplicity production to iterative complexity production .Furthermore, these methods also respect the manufacturing processes and material properties of nodes. The structure was fabricated using robotic fabrication techniques after design optimization using parametric computationally driven manufacturing processes. In order to move from the computational design environment to joint fabrication, custom robotically process was developed to assemble making full structure series of nodes which saved time; cost; and exerted effort if compared to the traditional mass production processes

Mitigation of welding distortion and residual stresses via cryogenic CO2 cooling - a numerical investigation

Fusion welding remains the most common and convenient fabrication method for large, thinplate welded structures. However, the resulting tendency to out-of-plane distortion exacts severe design and fabrication penalties in terms of poorer buckling performance, lack of fairness in external appearance, poor fit-up and frequent requirements for expensive rework. There are several ways to mitigate welding distortion and this study concentrates on the use of cryogenic CO2 cooling to reduce distortion. A feasible combination of welding process and cooling parameters, was investigated computationally and the resulting effects on final deformation were predicted. Three different computational strategies were developed and applied to butt-welding and fillet-welding processes, with and without the inclusion of cryogenic cooling. In the first method, a fully transient, uncoupled thermo-elastoplastic model was investigated. This method is comprehensive but not readily applicable to predict welding distortions in complex, industrial-scale, welded structures, due to the large computational requirement. More computationally efficient models are needed therefore and two further models of this type are suggested in this study. The results show good agreement between the different models, despite substantial differences in computational budget. In butt-welded plates, a significant decrease in out-of-plane distortion is obtained when cryogenic cooling is applied. In fillet-welded plates, cooling had much less effect on welding distortion. This was largely due to the size and configuration of the test case assemblies and the fact that the attached stiffener greatly increased the overall stiffness and resistance to contraction forces

Synthetic biology—putting engineering into biology

Synthetic biology is interpreted as the engineering-driven building of increasingly complex biological entities for novel applications. Encouraged by progress in the design of artificial gene networks, de novo DNA synthesis and protein engineering, we review the case for this emerging discipline. Key aspects of an engineering approach are purpose-orientation, deep insight into the underlying scientific principles, a hierarchy of abstraction including suitable interfaces between and within the levels of the hierarchy, standardization and the separation of design and fabrication. Synthetic biology investigates possibilities to implement these requirements into the process of engineering biological systems. This is illustrated on the DNA level by the implementation of engineering-inspired artificial operations such as toggle switching, oscillating or production of spatial patterns. On the protein level, the functionally self-contained domain structure of a number of proteins suggests possibilities for essentially Lego-like recombination which can be exploited for reprogramming DNA binding domain specificities or signaling pathways. Alternatively, computational design emerges to rationally reprogram enzyme function. Finally, the increasing facility of de novo DNA synthesis—synthetic biology’s system fabrication process—supplies the possibility to implement novel designs for ever more complex systems. Some of these elements have merged to realize the first tangible synthetic biology applications in the area of manufacturing of pharmaceutical compounds.