Question

Sketch a block diagram of a typical atomic force microscope, where the sample stage is moved, rather than the cantilever. Identify the important hardware and electronics components in the sketch. State the function of the following key components: Laser, Cantilever, PZT Scanner, Sample Stage, Photodiode, Computer / Electronics.

Answer 1

The Atomic Force Microscope is a type of device, which gives us the information about the surface profile of any nanoparticle.

The block diagram of an Atomic Force Microscope (AFM) is given below:

The function of the key components are given below:
1. Laser: Sharp beam of laser light falls on top of the cantilever.

2. Cantilever: The Cantiliver is the holder with the nanotip at the front part of it. The cantilever is sepereated from the surface of the sample within the nanometer scale and detects the slightest fluctuation on the surface by van der Waal's force.

3. PZT Scanner: Piezoelectric scanner measures the forces between a very thin measuring tip and the surface of the object.

4. Sample stage: The sample whose surface profile is to be investigated, is to be placed on top of the sample stage, which holds the sample in its position.

5. Photodiode: The photodiode detects the laser beams that are reflected from the cantilever. Thus, fluctuation in the cantilever leads to distortion in the laser received by the photodiode.

6. Computer/Electronics: The data received by the photodiode is transfered here. The computer analyses the data and then interprets it in a way, which is helpful for us. At the end of this process, we can see the surface profile of the sample on the computer screen