Interferometric force sensing AFM probes for nanomechanical mapping of material properties

In this paper, we describe an AFM probe that measures tip-sample interaction forces in tapping-mode AFM imaging. In our probes, a high-bandwidth interferometric force sensor at the end of the cantilever is coupled to the tip motion, and it is used to resolve tip-sample interaction forces with high temporal resolution. Measurements of the sensor signal show that the tip-sample interaction during imaging can be resolved with high sensitivity and high temporal resolution. In our experiments, the harmonics of the tip-sample interaction are used to map chemical and structural properties of the materials on the nanoscale.