Thermomechanically and electromagnetically actuated piezoresistive cantilevers for fast-scanning probe microscopy investigations

The self-actuating and self-sensing cantilevers make it possible to perform precise non-contact atomic force microscopy (AFM) surface investigations. The measurement and control precision in the bandwidth of up to 2 MHz is ensured by integration of the most important microscope components: the tip deflection actuator and the tip deflection detector with the spring beam. In this way the vast majority of the parasitic disturbances like resonances of a bulk piezoactuator used for the cantilever excitation are eliminated. In this paper we describe thermomechanical and electromagnetic technologies for the actuation of the cantilever vibration whose oscillation is detected using the piezoresistive deflection sensor. We present how to control the cantilever mechanics using both actuation methods. We discuss the differences in power consumption when the cantilever is actuated and what are the surface scanning features of both technologies. We show that an atomic force microscope is capable of retaining its imaging speed and resolution when its cantilever is actuated in the thermomechanical and electromagnetic way. The obtained results illustrate that the selection of the proper actuation method extends applicability of the proposed AFM technologies.