Introduction In the past two decades Atomic Force Microscopy (AFM) 1 has been recognized as a powerful characterization method of surfaces at small scales and in different environments. In addition to high-resolution visualization of surface morphology and nanoscale structures, AFM microscopes are also broadly applied for examination of mechanical, electromagnetic, optical and other properties. The core of this technology is the measurement and control of force interactions between a minute probe and a sample surface. Practically, such measurements can be performed at a single location and applied for surface imaging with contact or oscillatory techniques. The techniques complement each other yet studies of soft matter are mostly carried out with oscillatory amplitude modulation (AM) mode. 2-3
Despite an expanding penetration of AFM and the related scanning probe microscopy methods into academic and industrial research, a critical analysis of the existing capabilities of this method reveals a number of undeveloped areas that are essential for further progress of the fi eld. We will mention only a few of them. The current efforts towards imaging with true molecular and atomic resolution in different environments benefi t from an extension of frequency modulation (FM) mode4 to measurements in air and under liquid. 5 The improvement of noise characteristics of AFM electronics and the minimization of thermal drift of the microscopes will undoubtedly assist researchers using extremely sharp probes in achieving superior imaging resolution. In the probing of local mechanical and electric properties increasing attention is paid to multi-frequency measurements that offer new capabilities for quantitative analysis. Studies employing multi- frequency measurements in the broad frequency range help avoid cross-talk of topography with mechanical and electric tip-sample force effects and have other advantages. A successful realization of these possibilities simultaneously with improved resolution of imaging and mapping of materials’ properties will open new horizons for AFM characterization especially if these applications can be performed in the properly-controlled environments. This goal can be achieved only in direct interplay of instrumentation developments and their practical verifi cation on various samples. This is our vision of advanced AFM and we hope that this paper supports it.