Fabricating Porous Structures using Robotic Hotwire Cutting

Vučić, M., Jovanović, M. and Raković, M., 2023. Fabricating porous structures using robotic hotwire cutting. Nexus Network Journal, 25(4), pp.849-866.

Abstract: With an increasing interest in fabricating complex structures in architectural design,
the concept of porosity has become a vital topic, opening up new avenues for tectonic
thinking and functional demands in architecture. Porous structures typically
consist of minute interstices or modular structural grids that allow fluids to pass
through and are typically present on a micro scale. By adopting a biomimetic approach,
which moves from the micro to the macro scale, the application of digital
tools has enabled the design of functional building elements. For example, the 30 St
Mary Axe tower by Foster and Partners imitates the shape and porosity of a Venus
Flower Basket Sponge, resulting in enhanced endurance capabilities. Furthermore,
porous structures can improve the building’s thermal, light, and air circulation conditions.
However, porous structures have a highly complex topology that poses a
challenge for the fabrication process, and is primarily limited to 3D printing and
CNC milling manufacturing approaches, with the addition of casting and chemical
processes depending on the material. In this research, we propose a novel design
and manufacturing approach for porous structure fabrication that uses a hot knife
tool with an industrial robot to cut expanded polystyrene materials. This approach
offers a faster and more efficient way to fabricate porous structures than additive
or milling techniques, with an integrated design approach that enables a range of
design scenarios to be explored. Additionally, our method provides hands-on experience
and practical testing of a large-scale prototype.