- 04.11.2021 -
NANO COLLOQUIA 2021 S3 Seminar Andrea Mescola
Date and Time: November 4, 2021 - 15.00
ONLINE https://global.gotomeeting.com/join/424632069
Speaker: Andrea Mescola
Title: Tunable Frictional Response of Induced Strained Graphene
Abstract:
In the nanoscale regime, one of the most plausible solutions to lower friction effects, reduce wear and protect surfaces, relies on coating them with ultrathin lamellar sheets, such as graphene monolayers. However, the role of the substrate on which graphene is deposited is not passive, but pivotal to modulate physical and electronic properties of the graphene film. In particular, strain induced by interaction with the substrate is one of the most interesting parameters to adapt and tune graphene characteristics[1,2]. Recent works suggested that also the tribological response of graphene could be modulated by strain or strain gradient fields[2–5].
In this context, our research activities aim to investigate the frictional response of graphene monolayer deposited over variously textured silicon substrates. In particular, the different pattern geometry of the host substrate we selected gives rise to multiple scenarios which range from a complete conformation to a whole suspension of the graphene layer which, in turn, correspond to different level of induced strain. The strained graphene surfaces were analyzed by Raman spectroscopy, analytical modeling and molecular dynamics simulations as well as through Frictional Force Microscopy (FFM) unraveling a clear frictional response dependency as a function of the scan direction with respect to pattern geometries.
These results are interpreted as an example of strain-dependent solid lubrication tuned by the morphology of the coated surface which can lead, in specific cases, to ultra-low frictional forces. These findings are applicable not only to graphene but also to other 2D materials and they provide novel fundamental insights related to the recent technology of miniature robotics and flexible electronics.
In this talk, I’ll resume the experimental studies I’ve worked on, with particular reference to our recently published manuscript[1]. I’ll discuss as well the pursuing of research activity focused on the performance of totally suspended graphene. Finally, I’ll briefly introduce the on-going activities about the mechanical behavior of carbon-based structures, e.g. carbon nano-onions with various hybridization degree, at different length scale.
References
[1] A. Mescola, G. Paolicelli, S. P. Ogilvie, R. Guarino, G. Mchugh, A. Rota, E. Iacob, E. Gnecco, S. Valeri, N. M. Pugno, V. Gadhamshetty, M. Rahman, P. M. Ajayan, A. B. Dalton and M. Tripathi, Small 2021, in press.
[2] S. Zhang, Y. Hou, S. Li, L. Liu, Z. Zhang, X.-Q. Feng, Q. Li, Proc. Natl. Acad. Sci. 2019, 116, 24452.
[3] C. Wang, S. Chen, Sci. Rep. 2015, 5, 1.
[4] X. Wang, K. Tantiwanichapan, J. W. Christopher, R. Paiella, A. K. Swan, Nano Lett. 2015, 15, 5969.
[5] C. Dai, Z. Guo, H. Zhang, T. Chang, Nanoscale 2016, 8, 14406.
Host: Massimo Rontani segreteria.s3@nano.cnr.it