Fraunhofer Institute for Microstructure of Materials and Systems IMWSContinuous fiber-reinforced filaments made from biopolymers and regional natural fibers are intended to make 3D printing more durable, sustainable, and cost-effective. As part of the “BioFiberFilament” project, the Fraunhofer Institute for Microstructure of Materials and Systems IMWS in Halle (Saale) is working with partners to develop high-performance filaments for demanding applications – initially with a focus on orthotics, and eventually also for medical technology, mobility, sports, and the furniture industry.
In additive manufacturing processes, currently available filament materials often reach their limits in technically demanding applications. Bio-based alternatives with high mechanical performance have also been virtually unavailable on the market to date. The Fraunhofer IMWS, FUSE GmbH from Zwenkau, and Sanitätshaus-Orthopädie-Technik F. Hellwig GmbH from Halle (Saale) therefore aim to jointly develop continuous fiber-reinforced bio-filaments made from regional natural fibers that are suitable for use in high-load-bearing components.
They are focusing on a material system that combines high-performance biopolymers – such as bio-based or biodegradable polymers like bio-polyamides or polylactic acid (PLA) – with virtually endless natural fibers derived from regionally available raw materials such as hemp or flax.
“By combining natural fibers and biopolymers, we aim to create an industrially viable filament that unites mechanical strength, resource efficiency, and regional value creation,” says Dr.-Ing. Patrick Hirsch, project manager at Fraunhofer IMWS. “For companies, this is an important step toward no longer viewing sustainability and technical performance as mutually exclusive.”
The starting point is a pre-impregnated unidirectional fiber composite semi-finished product (UD tape). This is first produced using a continuous impregnation process, achieving a high fiber volume fraction of over 40 percent. It is then cut into narrow strips and finally processed in a continuous forming process into a filament with a maximum diameter of 1.75 millimeters. The continuous fiber reinforcement promises a significantly higher level of mechanical performance than that of conventional short-fiber-filled filaments. Furthermore, high-performance filaments with continuous reinforcement have so far been available primarily with cost-intensive carbon or glass fibers. A bio-based alternative could reduce material costs.
Another key project goal is to ensure that the new biomaterial can be used on commercially available filament 3D printers designed for continuous-fiber-reinforced polymers, thereby enabling realistic deployment in industrial applications. A prosthetic socket serves as a demonstrator. This application is particularly relevant from a technical standpoint because it places high demands on strength, stiffness, weight, and customizability. At the same time, the advantages of additive manufacturing – such as patient-specific geometries – can be demonstrated particularly well here.
The Fraunhofer IMWS plays a central role in the project by evaluating the developed solutions from both a materials and process perspective. This includes, in particular, investigating the impregnation behavior of natural-fiber-reinforced semi-finished products, analyzing their formability into printable filaments, and assessing their processability in existing 3D printing systems. In addition, the institute contributes its expertise in microstructure characterization, in analyzing the relationship between material structure and mechanical properties, and in evaluating performance in medical technology applications.
“At Fraunhofer IMWS, we don’t view the material in isolation, but rather along the entire process chain – from the semi-finished product through the filament to the printed component,” says Patrick Hirsch. “It is precisely this understanding of the interactions between fiber, matrix, interface, manufacturing process, and subsequent component behavior that is necessary to transform a sustainable material concept into a robust industrial solution.”
Looking ahead, potential applications include medical technology, the sports equipment industry, the furniture and interior design sectors, household applications, and the automotive industry. Wherever lightweight, durable, and customizable components are needed, the developed material system can open up new possibilities.
The project is funded by the Federal Ministry of Education and Research as part of the “WIR! – Change Through Innovation in the Region” program.
(July 20, 2026)