Fast detection based on semi-transient signals in AFM

In this paper, a high-speed width detector is derived for use in atomic force microscopy (AFM). The algorithm rapidly determines the width by detecting the two edges of the sample during a fast scan. The algorithm is designed primarily as a first step towards detection of a single macromolecule moving on a biopolymer. This detector is an important component of a new approach in AFM, a control system that directly tracks the motion of these single macromolecules rather than deriving their motion from a sequence of images. Such an approach promises a much higher temporal resolution than is achievable in time-lapse imaging.