Effect of liquids on AFM imaging

AFM (atomic force microscope) imaging in liquids is very important in measurement science for bio-applications. This paper discusses the effect of liquids on AFM imaging. In a developed AFM system, a standard 2D grating was used for the study of AFM imaging in different liquids including deionzed water, DMEM (Dulbecco's Modified Eagle Medium) and DMEM with 10% of FBS (Fetal Bovine Serum). AFM images acquired from different liquids were analyzed in terms of the image contrast and standard deviation of the grating period by Matlab. The experimental results have shown clearly the different effects of liquids on AFM imaging. The AFM imaging quality in liquids is a function of different forces acting on the cantilever and is directly related to the physical properties of the liquids.