Figure 1: Scheme of bimodal nanomechanical spectroscopy.

(a) Scheme of a force curve. The shaded area indicates the dissipation introduced by repulsive interactions. The arrows indicate the direction of the tip motion. (b) Tip excitation in bimodal AFM. It has a large amplitude component tuned at the first flexural mode of the cantilever and a small component tuned at the second flexural frequency. (c) Scheme of the frequency shift, phase shift, amplitude reduction and correction in frequency modulation AFM. (d) Block diagram depicting the feedback controls in bimodal nanomechanical spectroscopy.(e) Scheme of the main observables and contact mechanics deformation. (f) Outcomes of the method.