Liquid-based additive manufacturing

In the field of liquid-phase-based systems, LKT is conducting research into the development of materials for SLA (stereolithography) in particular. In SLA, a liquid photopolymer is selectively exposed to a UV laser, causing the resin to cure layer by layer. Research focuses on the targeted modification of materials, the development of our own application-specific resin systems, the integration of fibers and process analysis.

In addition to systems that cure purely under UV light, there are also so-called dual-cure systems. The term “dual-cure” refers to the combination of two different curing mechanisms that are coordinated with each other and applied one after the other. These include primary curing by UV exposure and subsequent secondary curing by thermally induced cross-linking. While primary curing enables shaping and layer-by-layer component build-up, secondary curing serves to complete polymerization or initiate additional cross-linking reactions, thereby improving the final material properties. In this way, components with improved mechanical, chemical or thermal properties can be produced.

One potential application of additive manufacturing technology is the creation of biomimetic physical models of tumor vascular structures and surrounding blood vessels, which can serve as an experimental platform for the investigation of novel targeted drug delivery strategies. However, due to the inherent limitations of established additive manufacturing processes and materials, efforts are required to adequately map tumor properties. For example, the adaptation of material properties or the use of post-processing strategies must be investigated in order to achieve the desired properties of the components.

Research at the LKT focuses on the development of novel manufacturing concepts and methods for creating geometrically complex structures that model the fluidic processes within the vascular structures of tumors. Not only the derivation of 3D structures, but also the implementation of tissue properties such as wall topography, surface charge or micromechanics must be taken into account.

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Graduiertenkolleg 2590 SyMoCADS

• Synthetic Molecular Communications Across Different Scales: From Theory to Experiments
• Homepage: SyMoCADS
• Research at LKT in P6: production of physical tumour models utilizing additive manufacturing technologies which can be used for the magnet-field driven deposition of pharmaceutical materials
• Contact person at LKT: Daniel Fleischhauer, M.Sc.

One focus of research into liquid-phase additive manufacturing is the development of flame retardant-modified material systems. The integration of flame retardants in liquid-based polymers is of crucial importance for safety-critical industries such as the automotive, construction, electronics and aerospace industries. These sectors have particularly high requirements for fire protection and safety, combined with the need for lightweight and high-performance materials. Research at the Chair not only increases the safety of the end products, but also meets the strictest legal requirements in terms of fire protection and sustainability. These developments open up new fields of application for additive manufacturing and create technological advances for the future.

Particular attention is paid to the use of halogen-free flame retardants, which not only offer a high level of fire safety, but are also more environmentally friendly. These flame retardants reduce the flammability of components by either creating a protective barrier against the spread of fire or by preventing the access of oxygen. The aim is to develop safe and sustainable solutions.

Embedded Additive Manufacturing represents an innovative approach in the field of additive manufacturing, focusing on the production of components with low stiffness using a support medium instead of rigid support structures. The fundamental principle is based on dispensing low-viscosity silicone resins into a rheologically adapted support medium. In contrast to conventional extrusion-based systems, which are limited to the successive layer-by-layer construction of components, Embedded Additive Manufacturing enables omnidirectional material dispensing freely in space.

LKT particularly benefits from the use of complex robotic systems and the integration of state-of-the-art testing technology, and is conducting research on the potential of geometrically complex processing of medical material systems for biomechanically demanding applications.

High-dynamic centripetal molding encompasses a novel manufacturing process for the production of thin, multilayered components with micro-structured surfaces, based on polymerization-curing elastomer systems. By harnessing extremely high centripetal forces at rotational speeds of several thousand revolutions per minute, the process enables the adhesion-controlled formation of precisely tolerated walls in the sub-millimeter range.

Our research includes investigating the impact of flexibly positioning the axis of rotation, which allows for a significant increase in geometric complexity as well as the locally divergent adaptation of layer thicknesses and mechanical properties, compared to a fixed rotational axis.