Scalable production infrastructure for extrusion-based additive manufacturing of personalized medical scaffolds

Personalized medical products are becoming increasingly important, especially in the field of regenerative medicine. Part of this development is represented by bioresorbable scaffolds, which are adapted to the individual geometries of patients and used for the reconstruction of tissues and organs. Extrusion-based 3D printing is one of the most established manufacturing technologies for these three-dimensional scaffold structures. The state of the art shows that essential process steps, such as printer parameterization, material handling, print monitoring, and inspections of the finished products and their quality assessment, are performed manually. These approaches are difficult to scale and limit the efficiency of the production. Since the entire production of medical scaffolds must take place in a controlled, regulatory-compliant cleanroom environment, humans involved in the production chain pose a risk of contamination and error, which highlights the advantages of an automated solution. The design of an appropriate automated production infrastructure for the manufacture of personalized scaffolds has been identified as a research gap and is the objective of this work. The topic is being investigated conceptually and by utilizing physical demonstration systems and digital models. Central result of the work is a concept for a novel production infrastructure based on a magnetic planar drive system. This planar drive is used for production intralogistics and enables a multi-agent approach for flexibilization and simultaneous processing of multiple print jobs in the sense of decoupled production. On the other hand, the individual agents of the planar drive, referred to as movers, are used as print beds and the horizontal kinematics for 3D printing, allowing the printing processes of the individual layers, intralogistics, and other process steps, such as quality control, to be seamlessly connected. To validate these approaches, a demonstrator was developed and used for feasibility studies. In parallel, a digital representation of the production infrastructure was created and implemented in an event-discrete simulation environment. It was demonstrated that the digital model can realistically replicate the decoupled process flows of the physical demonstrator. Furthermore, simulation studies proved that the model can be used for planning the scale-up of the production. The usability of the model for optimizing production processes was also investigated in simulation studies. These optimizations relate to the design of the production platform layout, including the arrangement of individual stations or the optimization of technical parameters such as process and transport speeds. The investigations show that the developed concept is not only suitable for the production of personalized medical scaffolds but also has the potential to be transferred to other applications.