Thermal tune method advice.

Marko posted on Wed, Jul 7 2010 3:03 AM

rated by 0 users

Hi All,

I am seeking advise on using the thermal tune method to derive the 'k' value for soft cantilevers ( res freq about 15kHz ).

At the moment, to do this, I operate a D3100 as follows:

1. In contact mode, approach a hard sample ( metal sample holder ) and acquire a force Vs distance curve to calibrate the piezo sensitivity.

2. return to image mode and set the gains to zero and the scan area to zero.

3. Using stepper motor, raise the tip well above sample ( at least 40 microns )

4. Set the channel 1 to record deflection, all other channels turned off,  the scan rate to 61Hz and resolution to 512 pixels. This yields a maximum sampling rate of about 62kHz.

5. Acquire an image or of the deflection.

6. Execute a power density spectrum of the image in the x direction

7. Move the cursors so that they enclose the resonant peak only and record the value ( this should be equal to the average vibrational amplitude in nanometers squared ).

8 Apply this value to the thermal tune equation.

Does this make sense and has any one else done this? The numbers seem to make sense but I would like confirmation.

Kind regards,

Marko