Harnessing Forces and Heat at the Nanoscale: From Nanomechanics to Thermal NanoLithography
The ability to harness forces and heat at the nanoscale opens up a variety of possibilities, from advancing current knowledge in the general field of nanomechanics, to nanopatterning materials with unprecedented capabilities. The focus of my laboratory is to combine forces and heat in innovative atomic force microscopy methods for the study and fabrication of materials and solid-liquid interfaces at the nanoscale.
In this seminar I will present our newly developed method to perform sub-Å-resolution indentations, which allow for high resolution elasticity measurements of films that are atomically thin and extremely stiff . In particular, we recently showed that at room temperature and after nano-indentation, two-layer graphene on SiC(0001) exhibits a transverse stiffness and hardness comparable to diamond, is resistant to perforation with a diamond indenter and shows a reversible drop in electrical conductivity upon indentation . I will discuss these results and new directions.
In the second part of the seminar I will present our recent results on thermo-chemical Scanning Probe Lithography , tc-SPL, invented in our laboratory in 2007. tc-SPL uses a localized source of heat to activate a chemical reaction and fabricate micro- and nano-structures of a variety of materials. Here, I will discuss our new findings on the use of tc-SPL for patterning metal electrodes on 2D materials and design bio-interfaces with single-enzyme resolution.
1. “Elastic coupling between layers in two-dimensional materials” Nature Materials 14 (7), 714-720 (2015)
2. “Ultra-hard carbon film from epitaxial two-layer graphene” Nature Nanotechnology 13, 133–138 (2018), doi:10.1038/s41565-017-0023-9
3. “Patterning metal contacts on monolayer MoS2 with vanishing Schottky barrier via thermal nanolithography" Nature Electronics 2, 17–25 (2019), doi: https://doi.org/10.1038/s41928-018-0191-0