Figure 5: Shows all of the components and subsystems of an atomic force microscope
system.
(Z) Coarse Z motion translator- This translator moves the AFM head towards the surface
so that the force sensor can measure the force between the probe and sample. The motion
of the translator is usually about 10 mm.
(T) Coarse X-Y translation stage - The XY translation stage is used to place the section
of the sample that is being imaged by the AFM directly under the probe.
(X-P) X and Y piezoelectric transducer - With the X and Y piezoelectric transducer the
(Y-P) probe is moved over the surface in a raster motion when an AFM image is measured.
(FS) Force Sensor - The force sensor measures the force between the probe and the sample
by monitoring the deflection of a cantilever.
(ZP) Z piezoelectric Ceramic - Moves the force sensor in the vertical direction to the
surface as the probe is scanned with the X and Y piezoelectric transducers.
(FCU) Feedback control unit - The feedback control unit takes in the signal from the light
lever force sensor and outputs the voltage that drives the Z piezoelectric ceramic. This
voltage refers to the voltage that is required to maintain a constant deflection of the
cantilever while scanning.
(SG) X-Y signal generator - The motion of the probe in the X-Y plane is controlled by the
X-Y signal generator. A raster motion is used when an image is measured.
(CPU) Computer - The computer is used for setting the scanning parameters such as scan
size, scan speed, feedback control response and visualizing images captured with the
microscope.
(F) Frame - A solid frame supports the entire AFM microscope. The frame must be very rigid
so that it does not allow vibrations between the tip and the surface.
Note - Not shown, is an optical microscope that is essential for locating features on the
surface of the sample and for monitoring the probe approach process.
