Electronically conductive networks of nano- and microparticles in printed electronics, soft robotics, and batteries
Professor Dr Tobias Kraus
- Leibniz-Institute for New Materials
Friday 25 November, 12.15pm
Abstract
Modern devices require multifunctional materials that combine properties such as mechanical flexibility, optical transparency, and electronic conductivity. This can be achieved in heterogeneous, hybrid materials with components that arrange into hierarchical structures during their processing. This talk will focus on electrically conductive networks inside such materials.
I will discuss the geometry of fillers such as fractal carbon black, spherical metal micro- and nanoparticles, and ultrathin wires. Their interactions in precursor liquids are quantified via light and X-ray scattering. The structure of the networks that they form during processing is deduced via cross-sectional electron microscopy and tomography.
Macroscopic electronic conductivities depend on the hierarchical network geometry and the interfaces in the hybrid material. I will outline process-structure-property relations for transparent printed electrodes, stretchable conductive leads, and battery electrodes and discuss how digital platforms can support the transfer of fundamental insights at different length scales to industrial practice.
About the speaker
Prof. Dr. Tobias Kraus is a chemical engineer and materials scientist trained at TU Munich, MIT, and the University of Neuchâtel. He obtained his PhD at ETH Zurich and the IBM Research Laboratory, where he worked on the assembly of particles at interfaces, particle transfer through controlled adhesion, and the creation of functional interfaces and structures with particles.
Today, Tobias works at the INM – Leibniz-Institute for New Materials in Saarbrücken, Germany. He has been head of the Program Division “Structure Formation” since 2014. In 2016, he became full professor for colloid and interface chemistry at Saarland University, where he teaches and supports the strong collaboration between INM and University.
In his research, Tobias curtails the interactions between particles, polymers, and small molecules. This leads to predictable, hierarchical assemblies for structured interfaces and functional materials. His group investigates hybrid materials for flexible and transparent electronics, reversible interfaces for soft and recyclable electronic devices, optical sensors, and their formation during 2D and 3D printing.
Fundamental problems of nanoparticle structure, network formation, and self-assembly are investigated with a combination of small-angle X-ray scattering, light scattering, electron microscopy, and optical spectrometry. The group establishes analytical and digital models of structure formation and applies them for the creation of new materials with rationally designed morphologies.
