ABSTRACT
This chapter introduces basic operational aspects of atomic force microscopy (AFM). Cantilevers are very often made of silicon or silicon nitride. Each single cantilever is characterized by its material properties and geometry: length, width, thickness, and shape. The most common system detecting the deflection of the cantilever is composed of laser and position-sensitive photodetector, which active area is divided into four quadrants. Commercially available AFM systems are equipped with a feedback loop that is used to control and maintain a constant interaction between the probing tip and sample surface during its scanning. In the AFM, the precise manipulation of the sample and its scanning is executed using piezoelectric devices that provide adequate displacement sensitivity and fast initial response times. To investigate the sample properties by the AFM, the force spectroscopy mode is widely applied. The quantitative force measurements, carried out using force spectroscopy mode, require an accurate knowledge of the cantilever spring constant.
