Fast nanomechanical spectroscopy of soft matter.

A method that combines high spatial resolution, quantitative and non-destructive mapping of surfaces and interfaces is a long standing goal in nanoscale microscopy. The method would facilitate the development of hybrid devices and materials made up of nanostructures of different properties. Here we develop a multifrequency force microscopy method that enables simultaneous mapping of nanomechanical spectra of soft matter surfaces with nanoscale spatial resolution. The properties include the Young's modulus and the viscous or damping coefficients. In addition, it provides the peak force and the indentation. The method does not limit the data acquisition speed nor the spatial resolution of the force microscope. It is non-invasive and minimizes the influence of the tip radius on the measurements. The same tip is used to measure in air heterogeneous interfaces with near four orders of magnitude variations in the elastic modulus, from 1 MPa to 3 GPa.