Additive Manufacturing of Variable-Density Ceramics, Photocatalytic and Filtering Slats Pavel Aguilar 1 , Luis Borunda 2 , Cristina Pardal 3 1,3 Polytechnic University of Catalonia 2 Polytechnic University of Madrid 1,3 {pavel.aguilar|cristina.pardal}@upc.edu 2 lborunda.eco@etsav.cat Additive Manufacturing (AM) offers the potential development of novel architectural applications of ceramic building components that can be engineered at the level of material to the extent of designing its performance and properties by density variations. This research presents a computational method and fabrication technique emulating complex material behavior via AM of intricate geometries and presents components with photocatalytic and climatic properties. It proposes an innovative application of AM of ceramic components in architecture to explore potential bioclimatic and antipollution performative use. Lattices are defined and manufactured with density variation gradients by tracing rectilinear clay deposition toolpaths that induce porosity intended for fluid filtering and to maximize sun exposure. The design method for photocatalytic, particle filtration and evaporative cooling local characterization introduced by complex patterning elements in architectural envelope slat components processed with radiation analysis influenced design are validated by simulation and experimental testing on specimens manufactured by paste extrusion. Keywords: Ceramic 3D Printing, Paste Extrusion, Photocatalytic Filter, Performative Design 1 BACKGROUND Initially intended for Rapid Prototyping, Additive Manufacturing (AM) technologies are increasingly being adapted to functional component production (Sass, Oxman 2006). Its application in architecture has been quickly growing (Malé 2016, Bock 2015) since the public release of patents of the most popu- lar AM technique, Fused Deposition Modelling (FDM) (Ngo, Kashani et al. 2018). The process of 3D printing is founded on the principle of stacking increasingly in height layer upon layer of a given fluid material, typically thermoplastic, deposited through a numerically controlled mech- anism. Typically, FDM systems work by applying pressure to extrude a fused thermoplastic and sub- sequent vitrification along an addition of discrete planes with continuous toolpaths, each toolpath consisting of concatenated coordinates and electro- magnetic commands (gCode) to approximate a 3D modeled component by layers. Translating the vir- tual model into a stacked set of toolpaths is called “slicing” where, for purpose of rigidity, the interior of the model is infilled with a constant geometrical pat- tern (Kulkarni, Marsan et al. 2000). D1.T2.S1. HEALTH AND MATERIALS IN ARCHITECTURE AND CITIES - Volume 1 - eCAADe 38 | 97