Electric Tune

When evaluating Surface Potential, you can also tune the cantilever electrically. Traditional cantilever tune oscillates the cantilever via the tapping piezo (see Figure 1). Electric Tune sweeps the frequency of the electric field surrounding the cantilever (see Figure 2). The force of the electric field moves the cantilever. The cantilever amplitude is then plotted in the Generic Sweep dialogue box.

Figure 1: Traditional cantilever tune, Tapping peizo resonates the cantilever

Figure 2: Electric field tuning, changes in the electric field frequency resonates the cantilever

Procedure

1. While evaluating Surface Potential in Realtime mode, select Microscope > Generic Sweep. The Generic Sweep dialogue box, shown in Figure 3, will display.

Figure 3: Typical Generic Sweep

2. Select Interleave as the Mode (see Figure 3).
3. In the Generic Sweep dialog box, set the Sweep parameters Input igain and Input pgain to 0. This disables the Surface Potential feedback loop, which works to keep the cantilever's amplitude at zero.
4. You can adjust several parameters to acquire interesting data: 
   • Try changing the Data Scale, Drive Phase and Drive Amplitude (see Figure 4).
   • Try changing the channel. For example, the Data Type can be changed to Potential Input.
   • Try sweeping another channel. For example, set the Graph parameter Sweep Output to Bias (see Figure 4).

Figure 4: Electric Tune Generic Sweep while adjusting the Drive Amplitude and Drive Phase

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