A bi-direction asymmetric fast scanning method

As a versatile instrument, an atomic force microscopy (AFM) has been widely utilized in many fields. However, when imaging biological samples, the scan area typically covers some unnecessary sub-areas which provide no useful information yet decrease scanning speed. Moreover, traditional scanning method has to include two parts of forward scanning and opposite scanning, where the opposite scanning almost takes the same time as the forward one yet it makes little contribution for the image construction of the sample. To overcome these problems, in this paper, we propose a novel bi-direction asymmetric fast scanning method specifically designed for biological samples, which reduces scanning time vastly and acquires higher-quality imaging for samples. To be specific, we first forward scan a sample quickly to distinguish interested areas from un-interested ones. Based on this part of knowledge, the opposite scanning process is then implemented with varying scanning frequency for distinct areas, with interested areas carefully scanned while uninterested ones skipped through quickly, so as to enhance imaging performance and reduce scanning time. As demonstrated by simulation and experimental results, when compared with the conventional scanning method, the proposed bi-direction asymmetric fast scanning method distributes the scanning time more intelligently, and due to this merit, it provides a more reliable image for biological samples with less scanning time.