Direct observation of the atomic force microscopy tip using inverse atomic force microscopy imaging

It is a well‐known fact in scanning probe microscopy that the tip geometry will be convoluted with the shape of the sample. In this study we report on a clear‐cut in situ direct observation of the real shape of the atomic force microscopy (AFM) tip using the AFM technique itself, utilizing a specially designed sample. The sample was an array of columns fabricated using aerosol deposition of metal particles and subsequent plasma etching. In this article we report on the so‐called inverse AFM mode in which the tip is actually used as the sample and vice versa. We will present results using ordinary AFM tips and ‘‘tapping‐mode’’ tips as well as high‐aspect‐ratio supertips (Nanoprobe). We propose how this method can, with a very high accuracy, be used for studying objects, e.g., biomolecules, that are deliberately attached to the usual AFM cantilever tip. Finally, we discuss how this method can significantly increase the reliability of the obtained AFM images.