Robotically 3D printed architectural membranes from ambient dried cellulose nanofibril-alginate hydrogel

Abstract

Cellulose nanofibril hydrogel mixed with an aqueous solution of sodium alginate is a novel bio-based material suitable for 3D printing of lightweight membranes with exquisite properties and sustainable traits. However, fundamental knowledge enabling its applications in architectural design is still missing. Hence, this study examines the macro-scale features of lightweight membranes from cellulose nanofibril-alginate hydrogel, relevant for the design of various interior architectural products, such as wall claddings, ceiling tiles, room partitions, tapestries, and window screens. Through iterative prototyping experiments involving robotic 3D printing of lightweight membranes, their upscaling potential is demonstrated. Correlations between toolpath designs and shrinkages are also characterized, alongside an in-depth analysis of coloration changes upon ambient drying. Further, the tunability potential of various architectural features, enabled by bespoke 3D printing toolpath design, is discussed and exemplified. The aim is to expose the wide palette of design possibilities for cellulose nanofibril-alginate membranes, encompassing variations in curvature, porosity, translucency, texture, patterning, pliability, and feature sizes. The results comprise an important knowledge foundation for the design and manufacturing of custom lightweight architectural products from cellulose nanofibril-alginate hydrogel. These products could be applied in a variety of new bio-based, sustainable interior building systems, replacing environmentally harmful, fossil-based solutions.