3D structures

3D dispenser printing and laser sintering

Dispensing printing technology
© Fraunhofer IWS Dresden
Dispensing printing technology
Dispenser printing of structures made of PEDOT:PSS and silver
© Fraunhofer IWS Dresden
Dispenser printing of structures made of PEDOT:PSS and silver

3D dispenser printing is a computer- controlled method with which a paste is applied to a substrate through a needle according to specified sizes and shapes (CAD). The applied material is dried and sintered on demand.

For sintering processes, primarily lasers of different wavelengths are used in order to adjust the energy introduced according to material and component. Typical materials of interest are metals, semiconductors, polymers, ceramics and composites. The simultaneous use of several printing heads enables to create components with integrated functionalities made of different materials.

Paste development for 3D printing

Rheometer for the characterization of pastes and inks
© Fraunhofer IWS Dresden
Rheometer for the characterization of pastes and inks

The fabrication of stable and rheologically optimized dispersions is necessary for the synthesis of printable pastes and inks for various applications. Therefore we combine metallic, semimetallic or ceramic micro- and nanomaterials with different polymer binder systems and additives to optimize the degree of dispersion and rheological characteristics.

Important parameters, among others, are particle size, type and concentration, the choice of binder systems, manufacturing processes, and furthermore, flow properties of resulting composite pastes. To assess suitability it is often not enough to just indicate a viscosity since properties such as dilatancy, height of zero shear viscosity or thixotropic behavior have serious influence on printing processes. The Printing team has excellent experience in particle dispersion, composite paste manufacturing and characterization.