The construction industry makes a significant contribution to global CO₂ emissions. Material extraction, processing, and demolition account for most of its environmental impact. As a response, there is an increasing interest in developing and implementing innovative biomaterials that support a circular economy, such as mycelium-based composites. The mycelium is the network of hyphae of fungi. Mycelium-based composites are renewable and biodegradable biomaterials obtained by ceasing mycelial growth on organic substrates, including agricultural waste. Cultivating mycelium-based composites within molds, however, is often wasteful, especially if molds are not reusable or recyclable. Shaping mycelium-based composites using 3D printing can minimize mold waste while allowing intricate forms to be fabricated. In this research, we explore the use of waste cardboard as a substrate for cultivating mycelium-based composites and the development of extrudable mixtures and workflows for 3D-printing mycelium-based components. In this paper, existing research on the use of mycelium-based material in recent 3D printing efforts was reviewed. This review is followed by the MycoPrint experiments that we conducted, and we focus on the main challenges that we faced (i.e., contamination) and the ways in which we addressed them. The results of this research demonstrate the feasibility of using waste cardboard as a substrate for cultivating mycelia and the potential for developing extrudable mixtures and workflows for 3D-printing mycelium-based components.

While prior studies have explored developing mycelium paste for EAM of this material, this research streamlined the EAM workflow for preparing living, extrudable mycelium mixtures, involving alterations in the preparation sequence and adjustments in the admixture ratios. The resultant mycelium mixture was employed in a series of experiments to optimize the parameters of robotic EAM using Artificial Neural Networks. Next, a performance-based acoustic wall was designed informed by simulation in Pachyderm. Building upon previous research by authors, two adjacent panels with high complex geometric features were selected for fabrication, presenting a challenging test scenario, as conventional planar slicing introduces stair-stepping phenomena, while non-planar slicing introduces irregularities in layer height. To address these, a hybrid slicing strategy was used by integrating both slicing techniques. Next, an experimental framework was established to assess the influence of EAM toolpath planning factors on the acoustic properties of the designed acoustic panels. Lastly, two panels were fabricated using an ABB IRB 2400 robotic arm. The alignment of the toolpath planning factors and EAM parameters resulted in a uniform material deposition in the final fabricated panels. This study underscores the transformative capacity of robotic EAM and conformal toolpath planning, presenting the development of biodegradable building materials and advanced acoustic solutions.

Mycelium-based composites, heralded for their functional versatility in architecture, have emerged as a pivotal subject in sustainable biomaterials research in recent years. Within this context, conventional fabrication techniques for mycelium-based composites, predominantly relying on molding, are increasingly deemed inadequate, and a shift towards more sustainable and flexible fabrication processes is necessary. Within the larger body of work studying additive manufacturing of mycelium-based composites, our study presents a robotic additive manufacturing approach employing hybrid slicing and conformal 3D printing to fabricate geometrically complex architectural panels. The panels, however, geometrically deform as fungi colonize the 3D printed substrates post-fabrication. Addressing this, we have integrated a computer-vision-based post-fabrication analysis, adept at meticulously documenting and quantifying geometric deformations occurring during the material cultivation stage. By harnessing the precision of conformal 3D printing together with this comprehensive post-fabrication analysis, our research presents a novel framework for accurate materialization and geometric analysis of mycelium-based composites, signposting the direction for future architectural endeavors.