AFM SMILER Exercise 1-4

Consider a uniform rectangular cantilever subject to a positive vertical load pointing upwards at its free end (like an AFM tip being pushed up by the sample), which location has the maximum strain within the cantilever material?

• Top surface at the fixed end of the cantilever

• Center line at the fixed end of the cantilever

• Top surface at the free end of the cantilever

• Bottom surface at the middle of the cantilever

Which of the following changes will result in the most significant increase of cantilever stiffness (assuming all other parameters remain unchanged)?

• Double the Young’s modulus of the material

• Increase the width from W to 4W

• Increase the thickness from T to 2T

• Decrease the length L to L/3

For cantilever analysis, what does the fix end boundary condition implies?

• The shear force is zero

• The moment is zero

• The vertical deflection is zero

• The internal strain is zero

Which subsystem of the educational AFM moves to achieve probe-sample engagement?

• Coarse positioner

• Signal processing circuit

• NI myRIO

• Buzzer-actuated scanner

Which component interfaces with the active cantilever probe directly to convert piezoresistor value change to voltage signal?

• Wheatstone bridge amplifier

• NI myRIO

• Signal processing circuit

• Buzzer scanner driver circuit

Which scanning mode in the simulator is the cantilever resonance oscillation excited?

• Pinpoint location mode

• Constant force mode

• Constant height mode

• Dynamic tapping mode

Which scanning pattern is utilized in the constant force mode for virtual imaging?

• Linear raster scan

• Spiral pattern scan

• Lissajous pattern scan

• Wood pecking scan

For the quadrature photodiode laser alignment, which of the following statement is true?

• The vertical signal should be maximized

• The horizontal signal should be maximized

• The sum signal should be maximized

• The sum signal should be set close to 0

In the system, there are two sets of coarse XY manual positioners. What does the XY positioner on the very bottom do?

• Move cantilever probe around to align with laser

• Move relative position between optical microscope and AFM system

• Move relative position between the cantilever probe and the sample

• Move the reflected laser to align with the quadrature photodiode

Which of the following step is absolutely necessary before optimizing signals on the quadrature photodiode?

• Load the sample on the sample stage

• Bring the sample area of interest into the optical microscope view

• Engage probe and sample

• Focus laser on the cantilever