Berin Šeta

The mechanical performance of short‐fiber‐reinforced polymers produced by Material EXtrusion Additive Manufacturing (MEX‐AM) is strongly influenced by the fiber microstructure formed during deposition. This work introduces a manufacturing‐aware topology optimization framework that exploits process‐induced microstructure control to enhance structural performance. A three-dimensional computational fluid dynamics model of the material deposition process is used to predict the spatial evolution of fiber orientation as a function of nozzle rotation speed, revealing a continuous transition from highly aligned to nearly isotropic. Based on these simulations, an effective material model is constructed in which the local elastic properties depend directly on the chosen nozzle rotation speed. This model is integrated into a density‐based topology optimization scheme that simultaneously determines the structural layout, the spatially varying fiber orientations, and the local level of anisotropy. The nozzle rotation speed acts as a design variable that allows the optimizer to tailor the anisotropy ratio throughout the structure. Numerical examples show that the framework naturally assigns highly aligned fibers to regions dominated by uniaxial loading, while favoring microstructures with low anisotropy in areas experiencing multi‐axial or shear‐dominated stress states. The results demonstrate the potential of coupling process‐level microstructure prediction with topology optimization to design fiber‐reinforced components for MEX-AM with spatially programmed material behavior. The proposed approach establishes a general pathway for integrating manufacturing physics with design optimization in additively manufactured structures.

Materials science underpins national economies and infrastructures worldwide, contributing significantly to the delivery of key services, as well as underpinning multiple industrial sectors, including space. The space sector, represents a cornerstone of technological progress, driving both direct and indirect innovation across many terrestrial fields. Taken together, materials science and the space sector represent a transformative frontier for innovation that remains only partially exploited, offering opportunities for scientific, economic, and societal advancement. In this context, this roadmap presents a special focus on where such interplay can yield fruitful outcomes over the next two decades, exploring specific intersections between these fields. The rationale behind this is routed in the current demand and forward view for specialised materials to address both terrestrial challenges and extraterrestrial ambitions, with the global space economy projected to reach $1.8 trillion by 2035, requiring a concerted focus on interdisciplinary collaboration. Microgravity provides a unique platform to achieve this, enabling critical insights, more precise control over material formation and the creation of advanced materials with enhanced properties for diverse applications. These breakthroughs are already informing terrestrial applications across industries, from semiconductors to pharmaceuticals, while laying the groundwork for advanced manufacturing in space. Emerging sectors such as the “In-Orbit Economy” and in-situ resource utilisation (ISRU) further underscore this critical opportunity, emphasising the need for resilient materials that can withstand the harsh conditions of space and utilise extraterrestrial resources sustainably. This roadmap brings together a diverse array of contributions covering relevant subjects across these areas—from space exploration and ISRU to the production of new inorganic, organic, and even “living” materials on microgravity platforms—while paying special attention to concrete examples, i.e. cases with a technological readiness level of 4 or higher, which warrant continued attention and effort.

This study correlated the thermally induced distortion of large-format additive manufacturing (LFAM) printed composite structures to the alignment of reinforcing fibers. During LFAM material extrusion, shear forces near the nozzle wall align reinforcing fibers in the print direction (x-axis). This produces a complex microstructure comprised of a “shell” of highly aligned fiber near the outer edge of the bead and a “core” of randomly oriented fiber in the center. Given the inherent anisotropy of high aspect ratio fiber reinforcement materials, the orientation of these fibers dictates thermomechanical response of the printed structure as it is heated to elevated temperatures. Understanding the extent and cause of this distortion is crucial for applications such as autoclave composite tooling such that resulting parts can maintain proper dimensional tolerance. This study documented the complex structure of LFAM composite parts using techniques such as microscopy, method of ellipses, extreme small-angle x-ray scattering, and micro-computed tomography scanning. Digital image correlation (DIC) was used to measure the thermally induced expansion of the printed part as it was heated. The variation in the thermomechanical response across the LFAM part was then correlated to fiber alignment effects, with higher y-direction expansion occurring in areas of the part where fiber was highly oriented fiber in the x-direction. Findings from this work can better address the knowledge gap in compensation modeling so that LFAM tooling can maintain correct dimensions during thermal cycling.