The combination of different materials is often key to the functionality of engineering components. For instance, metal films on polymers are omnipresent composite materials, from food packaging to satellite insulation and flexible electronic displays. Thereby, interfaces are often the weakest link, associated with dissimilar physical properties of adjacent layers or joining parts. A common strategy to prevent interface failure is enhancing adhesion. However, strong (inseparable) interfaces limit recyclability, an aspect largely neglected yet. Novel interface design could change this situation. This proposal outlines a research program to establish new scientific principles for the nanoscale design of innovative “programmable interfaces” with reliable adhesion in use and thereafter “debonding upon request”, aiming at a new generation of reliable and recyclable sustainable thin film composite devices. Recent work of the PI on naturally well-adhering Al on Polyimide (adhesion energy Γ=40 Jm-2) suggests how unique benefits can be mimicked artificially for weak systems (2 Jm-2) via molecular layers (Al-O-C Alucones) deposited at the interface. The PI hypothesizes that inseparability of metallization and substrate can be solved by incorporated “triggers” for controlled degradation and delamination in conditions beyond those of standard use, e.g. via local heating at the interface by optical excitation of metallic nanoparticles. ”InterBond” shall combine a) fabrication of inorganic-organic model interfaces with triggerable degradation mechanisms, b) in-situ testing of interface strength in service/trigger conditions and c) physical modelling of structural integrity as a function of material combination and architectural design. This research program will focus on interfaces in metal films on polymer, yet the outcomes should apply to lightweight polymer matrix composites with metallic or ceramic fillers, leading the path to sustainable materials for technical applications.

There are basically three mechanisms for spatial pattern formation in systems of two coupled reaction-advection-diffusion equations; the Turing patterns, patterns created through reaction kinetics, and chemotaxis patterns. We are interested in the reaction-diffusion equation with underlying chemotaxis. The terminus chemotaxis refers to oriented movements of cells (or an organism) in response to a chemical gradient. The topic of the proposal to investigate the logistic grow equation with underlying chemotaxis. This system will be perturbed by a stochastic noise term, modelling neglected fluctuations or random perturbations from outside. The stochastic term leads to new phenomena, e.g. bifurcation are smeared out, metastability may happen, or sudden shifts to other, possible undesired, states. First, the existence and uniqueness of the solution should be investigated; then the long term behaviour will be analysed. Here, also the dynamical behaviour should be characterised. The third point, we will focus on is the numerical approximation of the system.

Since the last decade, the number of isolated two dimensional (2D) materials keeps growing exponentially. The research community relies predominantly on synthetic single crystals, remaining limited to the variations of only several material classes. Naturally occurring van der Waals (vdW) crystals – 2D minerals – offer wider structural and compositional variety, but remain largely unexplored. Further, developing nanotechnology based on non-toxic and abundant surface minerals found in soils and clays will ensure sustainable, environmentally friendly, and biodegradable electronics. Recently, the focus of 2D electronics is largely on novel semiconductors, and spontaneously polarized materials. The number of vdW insulators is extremely disproportional to both semiconductors and metals. Almost exclusively the entire field relies on hexagonal boron nitride. Surely, this cannot be the only technologically relevant system, and new members would also open unexplored pathways in device design and functionality. With my project POL_2D_PHYSICS, I aim to introduce and establish a class of phyllosilicates as a multifunctional 2D materials platform. My project will explore their limits with respect to three applications: as gate dielectrics, as magnetic insulators, and as ferroelectric insulators. Starting from minerals, I will study their structure property relation. To bridge the gap between an interesting concept and a potential future technology, I will develop pathways to synthesize phyllosilicate single crystals and thin films with targeted properties for applications in 2D electronics. If successful, the project will develop scalable novel concepts in charge transfer doping, and implement the proposed materials class into multifunctional 2D polarization electronics. With high risk goals of delivering novel and air stable multiferroic and neuromorphic systems, POL_2D_PHYSICS has the potential to fundamentally impact the future of 2D electronics.

The ideal structural material should excel in strength and toughness. Strength describes the capability of a defect free component to carry load during operation, while toughness defines the load-bearing capability and ductility in the presence of a crack. For an energy-efficient and safe design, both quantities should be simultaneously high. Unfortunately, they are mutually exclusive, rendering their combination a Holy Grail in materials science. The reason for this incompatibility is rooted in the inverse strength-ductility paradigm. Focussing on metals, the strength is enhanced via microstructure refinement to the nanometer scale, but ductility and damage tolerance simultaneously drop dramatically. Safety-related or highly stressed components are thus made from rather soft metals, indicating tremendous economic impact conceivable. The objective of this project is to design new bulk materials that uniquely combine high strength and toughness. Severe plastic deformation will be employed to create novel nanostructured bulk metals and nanocomposites, utilizing atomistically informed alloy and interface design to promote plastic deformation. The largely unknown nanoscale processes that limit fracture toughness of nanostructured materials will for the first time be directly identified by quantitative nanomechanical fracture experiments performed in-situ in high resolution electron microscopes. Correlation of these unique insights with ab-initio calculations and energy-based elastic-plastic fracture mechanics computations will guide paths for further improvement of the fracture resistance. By combining a versatile synthesis technique with highly advanced in-situ nanomechanical testing permitting unique atomistic-level insights into nanoscale fracture processes and a scale-bridging modelling approach, new mechanism-based strategies to tailor innovative nanostructured metals and composites with unprecedented strength and toughness will be established.