PhD on multiscale design and testing of magneto-active mechanical metamaterials

Most of the designs of smart materials and mechanical metamaterials have to date focused on passive mechanical properties, such as maximum stiffness and minimum weight, negative Poisson's ratio or compressibility. The central objective of this project is a paradigm shift in the design of mechanical metamaterials in making them active, and thus significantly extending the provided design space and potential for functionalization by integrating on-demand real-time switchable properties. Join our team of scientists from Mechanical Engineering on this exciting journey to develop new smart materials and devices.

We are looking for a highly creative and motivated PhD candidate to join the Mechanics of Materials section at the Eindhoven University of Technology (TU/e). The position is in the group led by prof. Marc G.D. Geers and will be co-supervised by Ron H.J. Peerlings and Ondrej Rokoš.

Context. Metamaterials owe their name to their unprecedented effective behavior that typically cannot be found in Nature and that often combines contradictory properties, such as being ultra-stiff & ultra-light, or auxetic behavior. These properties usually emerge from the metamaterials' complex micro-structural morphology rather than from the properties of individual material constituents. Recent trends in metamaterial design aim at their actuation using, e.g., discrete mechanical, pneumatic, thermal, chemical, or electromagnetic actuation. Metamaterials thus offer a massive design space, which can be exploited in numerous applications such as artificial muscles, medical robotics including minimum invasive surgery, bio-implants, soft robotics, or self-folding systems.

Objective. The objective of this project is to theoretically and experimentally prove the concept of magneto-active mechanical metamaterials and to predict mechanical behavior relevant at the engineering scale, hierarchically emerging from the underlying microstructure.

Development of such materials relies on computationally intensive multi-physics first-principle microstructural models, which need to be parameterized by typical microstructural features such as geometry, micro-constituent material and magnetic properties, or coupling with external fields. Engineering-scale effective properties are essential in order to gain new insights into the underlying mechanisms and behavior of such materials, but are at the same time theoretically and computationally challenging.

A paradigm shift and advance in the state of the art of metamaterials is expected, by making them active and by developing new microstructures and concepts leading to target engineering properties and functionalities based on interactions with external magnetic fields.

Implementation. To achieve this objective, the PhD project is planned to cover several aspects of the design, multi-scale modeling, and testing of such materials. (i) In-silico numerical design and testing of magneto-active microstructures, by developing finite element modeling tools and estimating their effective properties (theoretically and computationally). (ii) Optimal microstructures and devices will be further sought for, using massive exploration of the available design space through inversion of the (micro)structure-property map. Topology optimization as well as machine learning based techniques will be considered. (iii) Smart-material devices and engineering applications will be considered, making use of available actuation concepts and gained insights. (iv) If successful, the best designs and actuation concepts along with proof-of-concept devices will be manufactured using 3D printing technology and tested experimentally.

Exposition. During the execution phase of this project, you will be exposed to, gain understanding, and deepen your knowledge in concepts such as complex nonlinear coupled multi-physics (electro-magneto-mechanical) modeling and simulation, advanced numerical and optimization tools including topology optimization, multiscale computational homogenization, finite elements, and machine learning tools. Collaboration with bachelor and master students is possible and welcome.

Section Embedding. The research will be embedded within the section Mechanics of Materials (www.tue.nl/mechmat ), whose activities concentrate on the fundamental understanding of various macroscopic problems in materials processing and forming, emerging from the physics and the mechanics of the underlying material microstructure. The main challenge is the accurate prediction of mechanical properties of materials with complex micro-structures, with a direct focus on industrial needs. The thorough understanding and modeling of 'unit' processes that can be identified in the complex evolving microstructure is thereby a key issue. The group has a unique research infrastructure, both from an experimental and computational perspective. The Multi-Scale Lab allows for quantitative in-situ microscopic measurements during deformation and mechanical characterization, and it constitutes the main source for all experimental research on various mechanical aspects of materials within the range of 10-9-10-2 m. In terms of computer facilities, several multi-processor-multi-core computer clusters are available, as well as a broad spectrum of in-house and commercial software.