Multilevel sequence detection for dynamic mode atomic force microscopy

The atomic force microscope is an instrument that is widely used in fields such as biology, chemistry and medicine for imaging at the atomic level. In this work, we consider a specific mode of AFM usage, known as the dynamic mode where the AFM cantilever probe is forced sinusoidally. In the absence of interaction with the sample being imaged, the cantilever follows a predictable sinusoidal trajectory. The deflection of the cantilever probe changes when it interacts with the sample being imaged and imaging is performed by interpreting these changes. In this work, we present a sequence detection based algorithm that allows for resolving topographic features into one of three possible levels at a fast speed. We demonstrate the effectiveness of our algorithm via simulation results and by comparing it to a lower bound that is obtained by considering a genie aided detector.