In multi-frequency AFM, contact-resonance imaging and band excitation techniques are used to discern material properties. Actuation at the contact resonance frequencies also reduces friction and enhances electrical contact quality. MF–AFM has also been shown to be suitable for mapping magnetic and electrical properties.
In spite of the promising nature of MF–AFM, quantitative MF–AFM remains a key challenge. A significant first step towards addressing this is the directed design of micro-cantilevers.
We have fabricated micro-cantilevers with integrated aluminum nitride actuators and conductive platinum silicide tips [2012-1]. These cantilevers exhibit excellent dynamic behavior. Ongoing research targets the development of a system-theoretical modeling approach for quantitative MF–AFM [2012-3] (Fig. 1).
Figure 1. Quantitative multi-frequency AFM.