Amplitude controlled oscillator for lateral force microscopy. High sensitivity and cheap and compact design without the use of lock-in detection systems

Lateral force microscopy appears as an attractive field for its applications as well as for the study of the physical nature of tip-sample interaction. We present a dynamic-mode lateral force microscope based on an amplitude-controlled oscillator whose frequency-selective element is a modified quartz tuning fork. The instrument is very compact and cheap and has high vertical sensitivity, while lateral resolution is limited by the oscillation amplitude of the prongs of the tuning fork. Experimental data on the oscillator itself are reported. Friction force operation has been demonstrated by use of approaching curves and open-loop imaging of the metal foil peeled off a compact disc.