Video rate atomic force microscopic imaging

Abstract

Atomic Force Microscopy (AFM) is a powerful imaging tool for exploring nano world. The advantages such as high resolution imaging both in air and liquid, easy sample preparing and vacuum free working environment make AFM very popular in the research of biology, chemistry and physics. However, usually, AFM imaging frame rate is too slow to get a dynamic observation of sample surface. This obvious disadvantage limits many potential using for AFM as a dynamic observation tool. Currently, there is an increasing demand on fast AFM imaging device or system, which could research as high as video rate. Many biochemistry experiments happen in seconds while traditional AFM usually takes minutes to image. Therefore, a video rate AFM imaging system is needed for this live sample continuously and dynamic observation. In this paper, a compressive sensing based video rate fast AFM imaging system is developed. There is nothing depending on the hardware modified for this fast imaging system. The only difference happens in data sampling process. Instead of scan the entire sample, this video rate imaging system only scan part of the topography of the sample as a compressed scan. After the data has been collected enough, an algorithm for image reconstruction is applied for recovering the AFM image. Because the compressive sensing is involved, it saves time expending on scanning-using short AFM tip scan trajectory in order to increase the imaging rate of AFM form several minutes per frame to seconds per frame.