01 Fakultät Architektur und Stadtplanung
Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/2
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Item Open Access Cross-sectional 4D-printing : upscaling self-shaping structures with differentiated material properties inspired by the large-flowered butterwort (Pinguicula grandiflora)(2023) Sahin, Ekin Sila; Cheng, Tiffany; Wood, Dylan; Tahouni, Yasaman; Poppinga, Simon; Thielen, Marc; Speck, Thomas; Menges, AchimExtrusion-based 4D-printing, which is an emerging field within additive manufacturing, has enabled the technical transfer of bioinspired self-shaping mechanisms by emulating the functional morphology of motile plant structures (e.g., leaves, petals, capsules). However, restricted by the layer-by-layer extrusion process, much of the resulting works are simplified abstractions of the pinecone scale’s bilayer structure. This paper presents a new method of 4D-printing by rotating the printed axis of the bilayers, which enables the design and fabrication of self-shaping monomaterial systems in cross sections. This research introduces a computational workflow for programming, simulating, and 4D-printing differentiated cross sections with multilayered mechanical properties. Taking inspiration from the large-flowered butterwort (Pinguicula grandiflora), which shows the formation of depressions on its trap leaves upon contact with prey, we investigate the depression formation of bioinspired 4D-printed test structures by varying each depth layer. Cross-sectional 4D-printing expands the design space of bioinspired bilayer mechanisms beyond the XY plane, allows more control in tuning their self-shaping properties, and paves the way toward large-scale 4D-printed structures with high-resolution programmability.Item Open Access Programming shape-change : integrative computational design of materials, mesostructures, and motion mechanisms for 4D-printing(Stuttgart : Institute for Computational Design and Construction, University of Stuttgart, 2024) Tahouni, Yasaman; Menges, Achim (Prof.)Shape-changing material systems are advantageous as passively actuated mechanisms for generating movement, with architectural applications ranging from adaptive building skins to the self-shaping manufacturing of building components. 4D printing, a technique that combines stimuli-responsive materials with additive manufacturing, is a promising method for the fabrication and programming of shape-changing structures. However, limitations in material responsiveness, programmability of shape-change, and the robustness of structures have constrained their functionality and real-world applicability. This dissertation introduces an integrative computational fabrication approach for the development of 4D printed hygroscopic material systems based on co-designing materials, mesostructures, and motion mechanisms. By tuning the material properties and structuring at hierarchical length scales, highly functional and precisely programmable 4D printed material systems have been developed. This material programming approach has been demonstrated through three studies, each focusing on one of the aforementioned aspects: by co-designing biobased cellulose-filled materials for 4D printing, the responsiveness of structures to target ranges of ambient relative humidity levels has been tuned; by precisely designing the mesoscale material structuring inside the 4D printed elements, their spatial and temporal shape change has been programmed; and through the development and utilization of computational fabrication workflows for 4D printing, novel motion mechanisms with enhanced functionality, such as motion amplification, have been created. The proposed material programming methodology and the developed material system have been implemented in the design and fabrication of SolarGate, a 4D printed, weather-responsive façade system installed on the LivMatS Biomimetic Shell. Consisting of 424 4D printed shading elements, the SolarGate regulates the solar heat gain of the building by providing adaptive shading in response to daily and seasonal weather cycles without consuming any operational energy. These results showcase the potential for creating an architecture that is highly functional, ecological, and in tune with the environment, being powered by and at the same time empowering the earth.Item Open Access Plants as inspiration for material-based sensing and actuation in soft robots and machines(2023) Speck, Thomas; Cheng, Tiffany; Klimm, Frederike; Menges, Achim; Poppinga, Simon; Speck, Olga; Tahouni, Yasaman; Tauber, Falk; Thielen, MarcBecause plants are considered immobile, they remain underrepresented as concept generators for soft robots and soft machines. However, plants show a great variety of movements exclusively based on elastic deformation of regions within their moving organs. The absence of gliding parts, as found in the joints of vertebrates and insects, prevents stress concentration and attrition. Since plants have no central control unit (brain), stimulus-sensing, decision-making and reaction usually take place noncentrally in the hierarchically structured materials systems of the moving organs, in what can be regarded as an example of physical intelligence. These characteristics make plants interesting models for a new group of soft robots and soft machines that differ fundamentally from those inspired by animals. The potential of such plant-inspired soft robots and machines is shown in six examples and is illustrated by examples applied in architecture and medicine.Item Open Access Weather-responsive adaptive shading through biobased and bioinspired hygromorphic 4D-printing(2024) Cheng, Tiffany; Tahouni, Yasaman; Sahin, Ekin Sila; Ulrich, Kim; Lajewski, Silvia; Bonten, Christian; Wood, Dylan; Rühe, Jürgen; Speck, Thomas; Menges, AchimIn response to the global challenge of reducing carbon emissions and energy consumption from regulating indoor climates, we investigate the applicability of biobased cellulosic materials and bioinspired 4D-printing for weather-responsive adaptive shading in building facades. Cellulose is an abundantly available natural material resource that exhibits hygromorphic actuation potential when used in 4D-printing to emulate motile plant structures in bioinspired bilayers. Three key aspects are addressed: (i) examining the motion response of 4D-printed hygromorphic bilayers to both temperature and relative humidity, (ii) verifying the responsiveness of self-shaping shading elements in lab-generated conditions as well as under daily and seasonal weather conditions for over a year, and (iii) deploying the adaptive shading system for testing in a real building facade by upscaling the 4D-printing manufacturing process. This study demonstrates that hygromorphic bilayers can be utilized for weather-responsive facades and that the presented system is architecturally scalable in quantity. Bioinspired 4D-printing and biobased cellulosic materials offer a resource-efficient and energy-autonomous solution for adaptive shading, with potential contributions towards indoor climate regulation and climate change mitigation.