PhD Tribomech - Triboelectric Energy Harvesting via Mechanical Design

The Cluster of Excellence livMatS develops completely novel, bioinspired materials systems that adapt autonomously to various environments and harvest clean energy from their surroundings. The intention of these purely technical – yet in a behavioral sense quasi-living – materials systems is to meet the demands of humans with regard to pioneering environmental and energy technologies. The societal relevance of autonomous systems and their sustainability will thus play an important role in their development. The research program of livMatS is characterized by highly interdisciplinary collaboration between researchers from a broad range of fields including engineering, chemistry, physics, biology, psychology, the humanities, and sustainability sciences.

The livMats Cluster of Excellence is offering the 2 PhD positions for the project:

Programmable Triboelectric Energy Harvesting through Mechanical Design (TriboMech)

Envisaged start date: 01.12.2022

Project description
Surfaces do often become charged after contact, a phenomenon called triboelectricity. They charge during contact and separation because their electron (or ion) affinities differ, in an analog to p-n or Schottky semiconductor junctions, where differences in charge carrier affinity lead to a space-charge region with internal potential difference. In triboelectric generators (TriboGens or TENGs, as frequently called in literature) similar phenomena are observed during a repetitive contact and separation of metals, semiconductors and insulators. Among the physical parameters influencing the performance of a TriboGen, i.e. power output and voltage, are contact force, chemical and/or physical properties of the mating surfaces, speed and dynamics of contact formation and release and, finally, its overall mechanical design.

This project will investigate the role of the aforementioned parameters through simulation, design and experimentation, and seek ways to optimize them to achieve, in the end, a high-performance TriboGen. Ideas are special contact formation-release structures, e.g. micro suction cups or bistable mechanisms for rapidly forming and breaking a contact in an adiabatic process and virtually “freeze” the separated charge. Micro-nanostructured surface topologies may create higher local surface pressure at the interface. Finally, the design of the TriboGen, its material and operation parameters will be optimized. Within this project a second doctoral student will work on adiabatic contact formation and separation on a purely theoretical/simulation basis. Close cooperation is expected and will be of mutual benefit. Also, another livMatS project is working on chemical surface effects in a TriboGen, with additional cooperation opportunities.

Candidate profile
We are looking for 2 candidates with a university degree in mechanical engineering, physics, microsystems (MEMS) engineering or a comparable subject. One PhD is focused on the design and experimentation of tribogenerators; the other PhD focuses on the theory and simulation of adiabatic contact formation. Your qualification will cover several of the following areas:
• in-deep experience in mechanical and multiphysics modeling and simulation, using software packages like COMSOL or ANSYS, but also analytical modeling and theory
• surface physics/chemistry and related solid state physics
• mechanical design (e.g. micro bending/torsional beams, deformable plates, resonant microstructures)
• microstructuring and microsystems design and cleanroom fabrication (e.g. photomask design, lithography, etching, physical vapour deposition)
• other related microfabrication technologies (e.g. laser micromachining, micro casting replication, electroplating)
• experience in the programming and operation of computer-controlled lab equipment (e.g. LabView) and measurement equipment (power supplies, multimeters, oscilloscopes)
• good knowledge of Matlab or comparable software

Please hand in:
• Letter of intent detailing which PhD project you are interested in and how your previous research qualifies you for the project (up to 1,500 words)
• Curriculum Vitae with list of publications (if applicable)
• Certified copies of your university degree(s) with grades (BA and MA certificate / Diploma certificate and transcript)
• Short summary of your master’s thesis (up to 1,000 words)
• Work sample (chapter from recent thesis or journal article, up to 5,000 words)
• Suggestion of two referees with contact details

Your documents will not be returned after the application process. For this reason, please submit copies only. This position is limited to 36 months. The salary will be determined in accordance with TV-L E13. We are particularly pleased to receive applications from women for the position advertised here.

Please send your application in English including supporting documents mentioned above citing the reference number 00002505, Application deadline is 30 September 2022. Application is to be emailed as ONE SINGLE PDF FILE to positions@livmats.uni-freiburg.de.

Direct all scientific questions about the project to Prof. Peter Woias