Combined Multimodal Nanomechanical and IR-Absorption AFM Modes for the Study of Soft and Bio-Sourced Materials

The study of mechanical properties of soft and bio-sourced materials at the nanoscale can be intrinsically challenging due to the wide range of Young Modulus to be sensed. Several modes from mechanical force curves to non-contact viscoelastic mapping or contact resonance frequency can be applied to cover for the different ranges as a function of the material stiffness. However, most of the biomechanical studies of interest require the combination of chemical sensitivity and nanomechanics to stablish a structural functional properties correlation at the nanoscale. In this regard, correlative nanomechanical and NanoIR absorption spectroscopy are a good approach, however, when performing IR-absorption spectroscopy in contact mode the chemical and mechanical response of the sample become intrinsically coupled.<br/>In this talk, I present the capabilities offered at CNMS, which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory, for mechanochemical and biomechanical studies. I will review several examples of biomechanical studies with combined nanomechanical and NanoIR measurements of biological tissues from shark vertebral cartilage to different types of cellulose based materials. Biological tissues display complex hierarchical structures, which require the nanoscale resolution of AFM to be morphologically and mechanically characterized. Taken together, this research enhances our understanding of structure-function relationships in hierarchical biological materials, particularly the nanomechanical response of fibrillar multi-component systems or mechanochemical changes in the mutant cell walls at a sub-cellular or nanoscale level.