In nanoscience, high spatial and spectral resolutions are of great importance in addressing questions related to material properties and more complex systems. The emergence of methods based on mechanical interactions such as the atomic force microscopy (AFM), which in many ways surpasses what can be achieved optically due to the inherent diffraction limit, has opened distinctive research opportunities for investigating surfaces across the full spectrum of scientific disciplines. More recently, the ability to noninvasively explore the subsurface for presence of material inhomogeneities also opens exciting routes towards the development of advanced nanoscale characterization platforms.
This seminar will focus on emerging methods for nanoscale mechanical and chemical fingerprinting of materials. The emerging concept of Mode Synthesizing Atomic Force Microscopy (MSAFM), a multifrequency technique that capitalizes on the nonlinear tip-sample interaction forces in AFM will be highlighted with examples of advanced exploration of complex systems. The engendered nanomechanical coupling in MSAFM, which offer a unique, highly sensitive route to monitor a host of physical properties can further be utilized as new resonances of an AFM system by means of another original concept coined the "virtual resonance". Thus, we will demonstrate that by varying the nature of the excitation, using elastic or photonic coupling, it is possible to obtain physical/elastic and chemical fingerprints of heterogeneous media with high spatial resolution.
Guided by results on 1- the investigation of nanoparticle-cell interaction, 2- the study of complex structures and composition of biomass plant cell walls, and 3- recent studies on novel nanomaterials, we will highlight the versatility of the work at the new NanoScience Technology Center Nanoscale Microscopy and Spectroscopy Lab. We will finally discuss the promising applications for disease-related and nanotoxicity challenges, including label-free subsurface imaging of living cells, multivariate nanoparticles-cell interactions, as well as other applications involving nanoscale devices.
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