Prior knowledge based fast imaging for scanning ion conductance microscopy

Scanning ion conductance microscopy (SICM) has becomes prevalent especially in probing biological samples taking advantage of its non-contact, force free, high resolution imaging ability. There are at least two imaging modes of SICM-continuous mode and hopping mode. In both imaging modes, the low imaging speed is the common disadvantage that hinders the efficiency of SICM based observation. In this paper, we propose a prior knowledge based fast imaging method to mitigate this problem. The key idea is to achieve a high resolution image on targeted features by scanning the sample twice, the first scan to obtain prior knowledge on targeted features with low resolution and the second scan to obtain images on targeted features with high resolution. In the first scan, the scanning speed can be very fast because the prior knowledge can be obtained from a low resolution image that requires few scanning points. In the second scan, only the interested areas (targeted features) are scanned. Because the scanning area on targeted features is much smaller than the whole scanning region, it takes much less time to obtain high resolution images on targeted features, As a result, the total time to acquire a high resolution is much less than the conventional one scan method. To verify the effectiveness of our proposed method, we performed high-resolution imaging on polydimethylsiloxane grating and microelectrode samples using a home-made SICM. The experimental results demonstrate the increased efficiency of SICM based observation using the twice scan method.