2 PhD Positions Nonlinear Dynamics of 2D Nanomechanical Systems

Micro and nanomechanical systems are being adopted in billions of products, that address a wide range of sensor and actuator applications in modern technology. The advent of two-dimensional materials, and the ability to fabricate atomically thin membranes like graphene, promises further device downscaling, enabling ultimate sensing capabilities that until recently were only dreamed of. However, owing to their small size, these membranes exhibit nonlinearities at nm amplitudes and obtain a wealth of nonlinear phenomena whose potential in sensing applications are to be explored. Unlike common practice, this project will consider nonlinear dynamics not as phenomena to be avoided, but rather as new tools that can be exploited for betterment of nanomechanical performance. The project will include 2 PhD positions. The first PhD topic revolves around using nonlinear phenomena resulting from mode coupling, nonlinear dissipation or phase transitions to improve the performance of resonant sensors in closed loop. And for the second PhD topic the goal would be to understand and elucidate the phenomena that arise from the interplay between fluctuations and nonlinear dynamics. This will be achieved by thinning down 2D materials and manipulating their geometry such that intrinsic fluctuations already drive them into the nonlinear regime. Both projects will thus involve fabrication, testing, and nonlinear dynamic characterization of 2D material resonators and oscillators.

The vacant positions are in the Dynamics of Micro and Nanosystems (DMN) group. The group focuses on exploiting dynamics of small-scale systems to create technologies that can lead to new products in the fields of scientific instrumentation, consumer electronics and healthcare. Our research spans from measuring and manipulating materials at the micro and nano scale, to the design of world-class MEMS and NEMS sensors and actuators.

You will be working in an international environment in one of the leading technical universities of Europe, with access to state-of-the art micro-nano testing facilities and advanced numerical modelling tools. You will be contributing to a challenging topic related to a European Research Council (ERC) Consolidator grant together with a team of 3 PhD students and 2 postdocs.

As a PhD student your tasks will include but not limit to:

• Mastering concepts from nonlinear dynamics, fluctuations, nanoresonators, and oscillators,
• Extending our existing theoretical and experimental frameworks in investigating dynamics of 2D materials,
• Contributing to the teaching and assisting with nonlinear dynamics and experimental modal analysis relevant courses at the department,
• Writing a PhD thesis, publishing in renowned computational journals, and presenting your research at international meetings.

Website and References for further reading: https://www.tudelft.nl/staff/f.alijani/

1. Manzaneque, Tomás, et al. "Resolution Limits of Resonant Sensors." Physical Review Applied 19.5 (2023): 054074.
2. Belardinelli, P., et al. "Hidden mechanical oscillatory state in a carbon nanotube revealed by noise." arXiv preprint arXiv:2312.14034 (2023).
3. Keşkekler, Ata, et al. "Tuning nonlinear damping in graphene nanoresonators by parametric–direct internal resonance." Nature communications 12.1 (2021): 1099.
4. Šiškins, Makars, et al. "Nonlinear dynamics and magneto-elasticity of nanodrums near the phase transition." arXiv preprint arXiv:2309.09672 (2023).