Analyzing sintered conductive materials with a numerical framework
Britt Cordewener defended her PhD thesis for the Department of Mechanical Engineering on May 6th.
There鈥檚 a big demand for flexible, stretchable and cost-effective electronic devices in this digital era. In response, (3D) printed electronics have gained significant momentum, enabling the fabrication of lightweight, customizable devices with embedded circuitry in a single production process. Though, key challenges such as the reliability of conductive interconnects prevent printed electronics from widespread adoption. Under mechanical strain, microscopic cracks can form within these materials, disrupting electrical conductivity and leading to premature device failure. Britt Cordewener presents a novel numerical framework within her PhD research to predict how cracks initiate and propagate in sintered conductive materials and how they contribute to increasing electrical resistance. This knowledge can be used to improve durability and ensure long-term functionality of printed and flexible electronics.
The model that Britt Cordewener developed provides valuable insights into the performance and failure mechanisms of printed electronics by simulating crack evolution in the microstructure of printed conductive tracks. It can be used by researchers to predict the reliability of 3D printed and flexible electronics in real-world applications. A critical aspect of this research is the analysis of the microstructure of sintered conductive materials, which forms when metallic nanoparticles bond under applied pressure or thermal treatment. The resulting microstructure significantly influences material performance. To accurately capture its complex behavior, a robust computational solution procedure based on the phase field method for fracture was implemented, capable of handling crack evolution while ensuring numerical stability in both two- and three-dimensional simulations.
Study of 2D and 3D geometries
The study evaluates representative 2D and 3D geometries, either reconstructed from material scans or statistically generated, to analyze key microstructural features that directly impact mechanical strength and electrical conductivity. By systematically studying the effects of metallic particle size distribution and sintering intensity, the findings demonstrate that enhanced sintering leads to improved electrical and mechanical properties, whereas particle size variations have a less pronounced effect.
A solid foundation
Although experimental validation remains a future step, this framework provides a solid foundation for studying the behavior of conductive sintered materials, supporting their reliable integration into next-generation electronic and power devices. By enhancing the understanding of how conductive inks respond to mechanical loads, this research contributes to the optimization of both material formulations and manufacturing processes, accelerating advancements in printed electronics.
This research is LEE-BED funded from the European Horizon 2020 research and innovation program under grant No. 81448.
Title of PhD-thesis: . Promotors: Associate Prof. Joris Remmers and Prof. Marc Geers.