Scanning probe microscopy: Tapping AFM

Benefit description

Tapping AFM also called Acoustic AFM is an intermittent contact mode of AFM in which the cantilever is driven by an alternating current. This measurement mode allows imaging of fragile samples that is not possible in contact mode. This measurement mode is based on the natural resonant frequency of the cantilever and can vary from cantilever to cantilever and it will be chosen depending on the sample to analyze. At the drive frequency, the tip moves up and down with a measurable amplitude that depends onthe distance to the sample (attractive or repulsive forces). When the tip-sample force is attractive, the amplitude increases and when the tip-sample force is repulsive, the amplitude is decreased. The Z-axis piezo adjusts to maintain the setpoint amplitude and, thus, generates the topography data as the cantilever is scanned across the sample surface.