Research

Craft-Inspired Digital Fabrication: A study of interactive robotic clay carving

A study of interactive robotic clay carving

   Digital fabrication protocols typically require precise linear programming. In a typical workflow, material is considered as a passive body onto which a design is imposed. This typical approach to digital fabrication separates design and making: Design ideation ends before making/fabrication begins. As a result, designers often miss the opportunity to design with the material and to incorporate in their designs intricate material expressions that can only emerge through an enactive and embodied process. Knowing that the enactive and embodied acquisition of making knowledge forms the cornerstone of craft, this study investigates how digital fabrication can gain craft-like qualities by allowing material expressions to be gradually discovered and mastered. We developed an interactive fabrication system by integrating force feedback into a robotic clay carving process. Based on the real-time force feedback, manual interactions with a robotic end-effector enable continuous carving of clay on-the-fly. The results of our experiments showed that intricate material expressions serendipitously appeared during this continuous carving, thereby, inspire new design ideas to form and gradually develop. Accordingly, our contributions are as follows: 1) an embodied interaction modality that continuously regenerates a fabrication action sequence so that its design space can be gradually learned, and then applied; 2) a craft-inspired digital fabrication workflow that supports design ideation through sketch, isolation, and composition of an intricate material expression; 3) a collection of critical considerations that relate our results to current discussions in interactive digital fabrication and material-driven digital fabrication. This study broadens digital fabrication in terms of adding improvisation, serendipity, and reflection.

Tokac, I., Gursoy, B., Bruyninckx, H., & Vande Moere, A. (2022, October 26). Craft-Inspired Digital Fabrication: A Study of Interactive Robotic Clay Carving. In Symposium on Computational Fabrication (SCF ’22), October 26–28, 2022, Seattle, WA, USA. https://doi.org/10.1145/3559400.3562003

Transforming unpredictable material effects into aesthetic expressions via sensor-informed fabrication grammars

Prototypes of cladding elements and artworks via formative clay carving: (a) Decorative cladding tiles with gradual textures were designed through fabrication by applying grammatical instantiations, that determine the size and height of the drop-shaped clay effects. (b) The drop-shaped effects were gradually morphed into serrated effects generating intricate textures onto a vase design. (c) Sculptural earings were designed through robotic fabrication via controlling emergent curl-like effects. 

A growing practice of robotics in architecture considers materiality as an active generator of design ideas.They argue that certain material behaviours, including eventual imprecisions or flaws, can lead to unique material textures that cannot be digitally modelled a priori. However, most of their technological advancements still require an iterative process of manual experimentation, that is later replicated via custom robotic implementations. This limits the design opportunities to material-specific application domains that simulate rather than capture material agency via feedback loops. In this series of artwork realisations, I demonstrate how fabrication grammar, a programming language grammar, allows controlling and composing aesthetic material expressions/textures with material agency. These textures were generatively fabricated based on a) a basic vocabulary of operational transformations; b) the sensed material conditions under which these transformations should take place; and c) the composition of these transformation and sensing rules to create a semi-controlled physical outcome. These realisations show how this grammatical approach enables controlling of unmodellable expressions due to material characteristics in the context of corrugated cardboard cutting and formative clay carving. The presented works also point to the potential towards sharing or combining semantically meaningful fabrication operations instead of their geometrical outcomes, which also opens the opportunity to produce fully unique material-sensitive customised products.

Robotically cut corrugated cardboard wall panels:  (a) The emergent frizzle effects was controlled to compose a pattern of curved lines crossing each other (top panels) and this pattern was enlarged by 2 times (bottom panels). (b) The pattern of curved lines (upper rows of the cardboard) was morphed into a pattern of polka dots (lower rows), of which was also composed by the frizzle effects. (c) Changing the morhing rule was resulted in fabrication of unpredictable patterns in between the curved lines (upper rows of the cardboard) and polka dots (lower rows). 

Celikyay, I. T., Philips, J., Bruyninckx, H., & Moere, A. V. (2021, October). Transforming unpredictable material effects into aesthetic expressions via sensor-informed fabrication grammars. IROS2021 IEEE/ Robotic Fabrication Workshop: Sensing in Additive Construction.

Fabrication Grammars: Bridging design and robotics to control emergent material expressions


(a) As the robotic arm was incrementally deforming the PETG plastic sheet (b) deeper with a spherical-tipped end-effector, (c) an emergent material expression is coined as a “fold’’. The robotic action sequence is defined in a “fold action rule” . (d) This action rule is combined with a transformation rule that gradually “enlarges” the fold expresssion by way of controlling the action parameters. 
The successive interim compositional states during the fabrication of the letter R from folds: (a) long extended fold, (b) short extended fold, (c) rounded fold, (d) diagonal fold, (e) horizontal folds. The folds are controlled in a way to fabricate R form by combining folding action rule with “extend” and “round” transformation rules.

Designers physically engage with a material to experience how certain characteristics allow the fabrication of unique expressions. In digital fabrication, however, this improvisational negotiation is typically replaced by a virtual simulation that predicts how a material expression can be fabricated, limiting the resulting design language to algorithmic forms. In contrast, we believe that digital fabrication can also produce ‘emergent’ material expressions that are so confounded that they appear slightly differently even when being produced by identical operations. This paper argues that such expressions can be executed by a domain-driven feedback paradigm, which integrates a human-in-the-loop to encode the tacit fabrication knowledge that is generated by reviewing intermediate outcomes. We encode this tacit knowledge by fabrication grammars, rule-based descriptions that causally relate fabrication parameters to qualitative descriptions of material expressions. By documenting a set of Single Point Incremental Forming (SPIF) experiments, this paper demonstrates how emergent material expressions can be controlled by semantically meaningful fabrication grammars, which even can be combined towards purposeful design goals. We believe our findings might allow the digital fabrication of material expressions that appear to have been produced manually or naturally; and support the future sharing of tacit fabrication knowledge.

Tokac, I., Philips, J., Bruyninckx, H., Vande Moere, A. with Vande Moere, A. (corresp. author) (2021). Fabrication grammars: bridging design and robotics to control emergent material expressions. Construction Robotics, 35-48. doi: 10.1007/s41693-021-00053-0

Material Sketching: Towards the digital fabrication of emergent material effects

Designing ’with’ fabrication operations:an example of reproducing variations of an emergent material effect on corrugated cardboard via cutting operations.

   Designing for digital or robotic fabrication typically involves a virtual model in order to determine and coordinate the required operations of its construction. As a result, its creative design space becomes constrained to material effects that can be predicted through digital modelling. This paper describes our preliminary thinking and first empirical results when this digital modelling phase is skipped, and the designing occurs “with” the fabrication operations themselves. By analysing the material responses of corrugated cardboard to simple linear cutting operations that are executed by a robotic arm, we demonstrate how emergent effects can be discovered through improvisation. Such material effects cannot be efficiently 3d-modelled, however, they can be created and controlled by the robotic manipulations.We believe this form of material sketching broadens the design space of digital fabrication towards novel and unforeseeable physical forms that require a much more direct, yet still digital, relationship with materiality. 

Tokac, I., Bruyninckx, H., Cannaerts, C., Vande Moere, A. (2019). Material Sketching: Towards the Digital Fabrication of Emergent Material Effects. In: (Extended Abstracts of CHI’19), (1-6). Presented at the Conference on Human Factors in Computing Systems, Glasgow, Scotland, UK, 04 May 2019-09 May 2019. ISBN: 978-1-4503-5971-9. doi: 10.1145/3290607.3313036