Atomic Force Microscopy: Principles, Instrumentation, and Applications

Question 1

What is a limitation of Atomic Force Microscopy (AFM) in materials characterization?

Accepted Answer

Slow data acquisition

Answer

High-resolution imaging

Answer

Non-destructive testing

Answer

Wide range of applications

Question 2

Which of the following is **not** a mode of operation in Atomic Force Microscopy (AFM)?

Accepted Answer

Scanning electron microscopy

Answer

Contact mode

Answer

Tapping mode

Answer

Magnetic force mode

Question 3

Which of the following properties can be measured using AFM's phase imaging mode?

Accepted Answer

Material Stiffness

Answer

Magnetic Susceptibility

Answer

Electrical Conductivity

Answer

Optical Reflectivity

Question 4

What is the primary function of the piezoelectric scanner in an AFM system?

Accepted Answer

Controls the precise positioning and movement of the AFM tip

Answer

Converts the AFM signal into an image

Answer

Detects the force applied by the tip

Answer

Amplifies the AFM signal

Question 5

In AFM, what is the purpose of utilizing a cantilever?

Accepted Answer

Detects the force interaction between the tip and the sample

Answer

Supports the AFM tip

Answer

Magnifies the sample image

Answer

Generates the AFM signal

Question 6

In AFM operation, what is the usual order of magnitude of the cantilever's deflection?

Accepted Answer

Nanometres

Answer

Centimetres

Answer

Millimetres

Answer

Micrometres

Question 7

What is a key advantage of AFM over other microscopy techniques?

Accepted Answer

Ability to characterize materials in their unaltered, native environment

Answer

Faster imaging

Answer

Higher magnification

Question 8

Regarding safety, what is the primary concern associated with AFM?

Accepted Answer

Electrical Hazards

Answer

Radiation Exposure

Answer

Chemical Hazards

Question 9

What is the primary role of the piezoelectric scanner in an AFM?

Accepted Answer

Precisely control the movement of the cantilever

Answer

Amplify signals from the cantilever

Answer

Detect deflections of the cantilever

Question 10

What is the key distinction between tapping mode and contact mode AFM?

Accepted Answer

Tapping mode minimizes the force applied to the sample.

Answer

Contact mode provides higher resolution images.

Answer

Tapping mode has a faster acquisition rate.

Question 11

What is the primary advantage of AFM over other surface characterization techniques?

Accepted Answer

Non-destructive and high-resolution imaging

Answer

High throughput and automation

Answer

Exceptional sensitivity and accuracy

Answer

Versatility and applicability to various samples

Question 12

How does AFM measure the mechanical properties of materials?

Accepted Answer

By detecting the deflection of the cantilever under applied force

Answer

By monitoring changes in electrical conductivity

Answer

By analyzing the optical absorption and reflection patterns

Answer

By measuring the acoustic waves generated in the sample

Question 13

Which of the following is the fundamental principle underlying Atomic Force Microscopy (AFM)?

Accepted Answer

Measuring the force interaction between a sharp probe tip and a sample surface

Answer

Scanning a sample surface with an electron beam

Answer

Measuring electrical current flow through a sample

Question 14

What is the primary function of AFM in materials characterization?

Accepted Answer

Nanoscale imaging of surface topography

Answer

Analyzing the crystal structure of a sample

Answer

Measuring electrical conductivity of a sample

Answer

Determining the chemical composition of a sample

Question 15

What is the primary advantage of employing a cantilever beam in AFM?

Accepted Answer

Precise control over the force applied to the sample

Answer

Enhanced magnification of the sample surface

Answer

Prevention of sample damage

Question 16

Which of the following is a key advantage of AFM over other microscopy techniques?

Accepted Answer

Ability to image samples in their natural state

Answer

Higher resolution than electron microscopy

Answer

Faster imaging speed than optical microscopy

Question 17

Which of the following is NOT an operational mode for Atomic Force Microscopy (AFM)?

Accepted Answer

Phase contrast imaging

Answer

Contact mode

Answer

Magnetic force microscopy

Answer

Tapping mode

Question 18

Identify the primary component of an AFM that interacts directly with the sample surface.

Accepted Answer

Cantilever with a sharp tip

Answer

Feedback loop

Answer

Laser detector

Answer

Piezoelectric scanner

Question 19

What is the primary advantage of using tapping mode AFM compared to contact mode?

Accepted Answer

Reduced sample damage

Answer

Higher resolution

Answer

Faster imaging

Answer

Improved signal-to-noise ratio

Question 20

What is the role of the feedback loop in AFM?

Accepted Answer

To maintain a constant tip-sample interaction force

Answer

To generate the AFM image

Answer

To calibrate the cantilever

Question 21

Which of the following is NOT a mode of operation used in Atomic Force Microscopy (AFM)?

Accepted Answer

Tunneling

Answer

Non-contact mode

Answer

Contact mode

Answer

Magnetic force mode

Question 22

Which component of the AFM is responsible for detecting the forces between the tip and the sample surface?

Accepted Answer

Cantilever

Answer

Laser

Answer

Feedback loop

Answer

Piezoelectric scanner

Question 23

What is the typical frequency range of AFM cantilevers?

Accepted Answer

Kilohertz to megahertz

Answer

Hertz to kilohertz

Answer

Gigahertz to terahertz

Answer

Megahertz to gigahertz

Question 24

Which of the following is NOT a potential application of AFM in materials science?

Accepted Answer

Protein sequencing

Answer

Characterization of nanocomposites

Answer

Analysis of thin films

Answer

Study of surface defects

Question 25

Which AFM mode is primarily used for measuring surface topography?

Accepted Answer

Contact mode

Answer

Magnetic force mode

Answer

Non-contact mode

Answer

Tapping mode

Question 26

Which of the following is NOT a common application of AFM?

Accepted Answer

Protein sequencing

Answer

Nanoparticle characterization

Answer

Biomaterial characterization

Answer

Surface roughness analysis

Question 27

What is the primary purpose of the piezo scanner in AFM?

Accepted Answer

Precise sample and cantilever positioning

Answer

AFM image generation

Answer

Force application

Answer

Cantilever deflection detection

Question 28

AFM is best suited for analyzing which type of sample?

Accepted Answer

Solid surfaces

Answer

Liquids

Answer

Vacuum

Answer

Gases

Question 29

What is the typical scan size range for AFM images?

Accepted Answer

100 nm - 100 μm

Answer

1 m - 10 m

Answer

1 nm - 10 nm

Answer

1 mm - 1 cm

Question 30

Which of the following is NOT a mode of operation for Atomic Force Microscopy (AFM)?

Accepted Answer

Transmission mode

Answer

Tapping mode

Answer

Phase imaging mode

Answer

Contact mode

Question 31

What is the primary purpose of the cantilever in AFM?

Accepted Answer

To detect interactions between the tip and the sample surface

Answer

To provide mechanical support for the tip

Answer

To amplify the surface topography

Answer

To generate the scanning signal

Question 32

What is the typical range of spatial resolution achievable with AFM?

Accepted Answer

Atomic to nanometer scale

Answer

Picometer to femtometer scale

Answer

Centimeter to meter scale

Answer

Micrometer to millimeter scale

Question 33

What types of information about materials can be obtained using AFM?

Accepted Answer

Surface topography, mechanical properties, and electrical properties

Answer

Magnetic properties

Answer

Chemical composition

Question 34

What is the fundamental principle behind the operation of AFM?

Accepted Answer

Detection of interatomic forces between an AFM tip and a sample surface

Answer

Measurement of electrical currents flowing through a sample

Answer

Use of electromagnetic radiation to image surfaces

Question 35

What is the primary function of the cantilever in Atomic Force Microscopy (AFM)?

Accepted Answer

To sense and respond to forces between the tip and the sample surface.

Answer

To generate X-rays for elemental analysis.

Answer

To focus an electron beam onto the sample surface.

Question 36

Which AFM operating mode is most suitable for imaging the surface of a soft, delicate biological sample without causing damage?

Accepted Answer

Tapping mode

Answer

Scanning tunneling microscopy (STM) mode

Answer

Contact mode

Question 37

Atomic Force Microscopy (AFM) can be used to map which of the following properties of a material?

Accepted Answer

All of the above

Answer

Surface topography

Answer

Mechanical properties

Answer

Electrical properties

Question 38

What information can be obtained from the force-distance curve acquired during an AFM experiment?

Accepted Answer

Adhesion force between the tip and sample

Answer

Optical properties of the sample

Answer

Crystalline structure of the sample

Answer

Chemical composition of the sample

Question 39

Which of the following is a limitation of Atomic Force Microscopy (AFM)?

Accepted Answer

Limited scan area compared to some other microscopy techniques

Answer

Requirement for high vacuum conditions

Answer

Inability to image conductive materials

Question 40

What is the role of the piezoelectric scanner in an Atomic Force Microscope (AFM)?

Accepted Answer

To precisely control the movement of the tip or sample in three dimensions

Answer

To detect the light emitted from the sample

Answer

To emit electrons for imaging the sample

Question 41

Which statement correctly describes the principle behind how an AFM produces an image?

Accepted Answer

The AFM measures the deflection of a cantilever as its tip interacts with the sample surface.

Answer

The AFM relies on the tunneling current between a sharp tip and the sample surface.

Answer

The AFM uses a beam of electrons to scan the surface and create an image.

Question 42

In AFM, what does the term 'resolution' refer to?

Accepted Answer

The ability to distinguish between two closely spaced features on the sample surface

Answer

The magnification power of the microscope

Answer

The speed at which the microscope can scan the sample

Question 43

What type of information can be obtained by analyzing the phase lag between the driving signal and the cantilever oscillation in tapping mode AFM?

Accepted Answer

Viscoelastic properties of the sample

Answer

Elemental composition of the sample

Answer

Crystalline structure of the sample

Answer

Optical reflectivity of the sample

Question 44

Atomic Force Microscopy (AFM) has found significant applications in which of the following fields?

Accepted Answer

All of the above

Answer

Materials science

Answer

Nanotechnology