Nanotechnology: A Maker’s Course complete course is currently being offered by Duke University, North Carolina State University & The University of North Carolina at Chapel Hill through Coursera platform. 

Week 1 - Main: Introduction and Essential Technologies for Nano

Q1. Nano-measurement tools typically involve bombarding a sample with particles such as:

• ball bearings
• electrons
• photons
• ions
• bacteria
• dust
• vacuum

Q2. What are challenges of nanoscale measurement compared to traditional measurement? (Select all that apply.)

• Can’t find a nanoruler at hardware stores
• The equipment is not readily available
• Humans can’t see at that scale with their naked eye
• Not every material can be characterized at the nanoscale

Q3. Which of the following are not typically conductive? Select all that apply

• Silver
• Polymers
• Gold
• Dielectrics/Ceramics
• Metals
• Biologicals

Q4. Particles in the open air do not cause defects in thin film deposition.

• True
• False

Q5. Which of the following are methods used to deposit thin films? (Select all that apply)

• Nano-imprint Lithography
• Screenprinting
• Chemical Vapor Deposition
• Vacuum Evaporation
• Painting
• Photolithography
• E-Beam Lithography
• Sputter Deposition
• Etching

Q6. When gowning before entering the cleanroom, you:

• start at the top (head) and work down to the bottom (feet)
• start at the bottom (feet) and work up to the top (head)

Q7. Typical molecules found in air include _____ (check all that apply)

• carbon dioxide
• silicon dioxide
• nitrogen
• oxygen
• silver

Q8. Match the vacuum pump categories to their general function:

a. Positive Displacement Pumps _____

b. Momentum Transfer Pumps _____

c. Entrapment Pumps _____

1. trap air molecules inside the pump, effectively removing the molecules from the chamber

2. bounce or deflect air molecules out of the chamber

3. push air out of the chamber

• a-3, b-1, c-2
• a-1, b-2, c-3
• a-2, b-1, c-3
• a-2, b-3, c-1
• a-3, b-2, c-1
• a-1, b-3, c-2

Q9. Which of the following are found in the electromagnetic spectrum? (Select all that apply)

• Time wave
• Seismic wave
• Beta ray
• Radio
• Alpha ray
• Microwaves

Q10. What is the best resolution of a microscope with a numerical aperture of 0.5 using energy with a wavelength of 2.8 nm?

• 3.36 nm
• 5.6 nm
• 3.36 pm
• 5.6 microns

Q11. As the velocity of an electron increases the wavelength of the electron will ________.

• stay the same
• decrease
• increase

Q12. What can occur when an electron beam interacts with a sample? (Select all that apply)

• Electrons in the beam will gain mass as they hit the sample.
• Electrons in the beam will multiply as they hit the sample.
• The beam will create a vacuum.
• Electrons in the beam will knock electrons out of the sample.
• The beam will pass through the sample.

Q13. As the velocity of an electron changes from 1.6 x 108

          m/s to 2.8 x 108

          m/s the wavelength of the electron will ________.

stay the same

decrease

increase

Week 2 - Main : Nano Measurement and Characterization Tools: Scanning Electron Microscopy and Energy-Dispersive X-ray Spectroscopy

Q1. What is an advantage of using an environmental scanning electron microscope?

• Samples can be coated with less expensive metals to prevent charging.
• The resolution is typically higher than traditional SEM.
• Wet samples can be imaged in their natural state without being dried.
• Images can be collected much more rapidly.

Q2. If you are interested in collecting SEM images that highlight surface features of your sample, which detector would be more appropriate?

• Backscatter
• Secondary electron

Q3. Which of the following uses electrons to generate images?

• Light microscope
• Electron microscope

Q4. In SEM, which of the following materials is often used to coat nonconductive samples?

• Polymer
• Glass
• Carbon
• Acetone

Q5. In SEM, after loading the sample and pumping the chamber to a low pressure, what is the first thing that should be done before collecting an image?

• Move the sample out of the chamber.
• Tighten the set screws on the sample stage.
• Focus the electron beam on the sample.
• Coat the sample with a conductive layer.

Q6. Which of the following information can be obtained through Energy Dispersive X-Ray Spectroscopy? (Select all that apply)

• Mass
• Weight
• Elemental Composition
• Feature Size
• Chemical Composition

Q7. What makes each element have a unique fingerprint in Energy Dispersive Spectroscopy (EDS)?

• Atomic number of elements in the sample
• Electron energy states in the element
• Mass of the atoms in the sample
• Amount of atoms in the sample

Q8. If an insulating sample is coated with a very small layer of gold to produce better images, gold will not be detected in the Energy Dispersive X-Ray Microscopy (EDS) experiment.

• True
• False

Week 3 - Main : Nano Measurement and Characterization Tools: Transmission Electron Microscopy

Q1. What is the major difference between SEM and TEM?

• Only TEM produces images of the sample
• Insulating samples can only be imaged in SEMs
• TEM uses smaller electrons than SEMs
• The electrons must pass through the sample in TEM

Q2. What are challenges of TEM? (Select all that apply)

• Aberrations related to lenses limit spatial resolution
• Requires ultrathin samples
• Sample image is a projection from 3D to 2D
• Environment around the microscope must be precisely controlled

Q3. In TEM, small changes in the environment, like vibrations from someone talking or a slight increase in temperature can affect imaging dramatically.

• True
• False

Q4. Using TEM, a researcher is able to image individual atoms.

• True
• False

Q5. What does a plasma cleaner do to a TEM sample?

• Washes the sample with detergent
• Coats the sample with a thin, clean layer of material
• Coats the sample with a conductive layer
• Removes debris and other particulates

Q6. Plunge freezing is a sample preparation method used for Cryo-TEM in which the sample is slowly cooled down.

• True. The sample should be frozen gradually.
• False. The sample should be cooled very rapidly.

Q7. Which is not a type of ice that can form at atmospheric pressure?

• vitreous
• hexagonal
• cubic
• octagonal

Q8. When performing biological sample prep for the TEM, which is not required safety equipment?

• lab coat
• safety glasses
• gloves
• ear plugs

Q9. The inside of the TEM is always under vacuum?

• True
• False

Week 4 - Main : Nano Measurement and Characterization Tools: X-ray and Optical Characterization

Q1. What happens when x-rays hit a very dense part of the sample?

• They are stopped or absorbed by it
• They are reflected backward
• They pass through it

Q2. In order to stabilize a sample for scanning it may be necessary to wrap it up before placing it on the stage. What would be the best material to package a sample in before running the MicroCT?

• Fill in container with cement to hold specimen firmly
• Light plastic bottle filled with cotton
• Dense plastic tube filled with tinfoil
• Stabilize with metal wire

Q3. Which of the following can be done with the final z-stack of images produced by the MicroCT?

• It can be used to create 3D models that can be 3D printed.
• It can be measured directly using free software like ImageJ
• It can be animated to show off the internal or external structure of the specimen
• All of the above

Q4. Using XPS you can obtain information about the chemistry of your sample’s ______.

• a. bulk
• b. surface
• c. both a and b
• d. none of the above

Q5. Electrons in a neutral/uncharged atom typically have _____ binding energies than electrons in an atom with a 4+ oxidation state.

• lower
• higher

Q6. Why are tweezers used during XPS sample preparation? (Select the best answer)

• To enable better sample conductivity
• To prevent sample contamination
• To protect the user as the sample is heated
• To help thin the sample prior to analysis

Q7. On the x-axis of an XPS plot is binding energy. What does this axis represent?

• The amount of energy required to remove electrons from an atom
• The amount of energy necessary to break bonds in a molecule
• The amount of energy needed to bind two atoms together
• The X-ray energy produced by the X-ray gun

Q8. What can XPS tell us about a sample? (Select all that apply)

• The oxidation state of elements on the surface
• The surface topography
• The elements present in the bulk
• The percentage of specific elements on the surface

Q9. The way light scatters or reflects depends on the size of an object.

• True
• False

Q10. Why might taking a scattering spectrum of nanoparticles take longer than taking a spectra of a bulk material?

• Nanoparticles scatter more light that is unfocused and cannot be collected
• Nanoparticles are small and scatter less light
• Bulk materials scatter light more quickly
• Bulk materials scatter light at higher energy

Q11. As the nanoparticle size changes, the peaks in the scattering spectra shift to different wavelengths.

• True
• False

Week 5 - Main : Nanofabrication: Vacuum Pumps and Thin Film Vacuum Deposition

Q1. The turbo-molecular pump, or simply turbopump, is an example of what type of pump:

• a high vacuum pump
• a low vacuum pump
• a rough pump

Q2. Why do the cooling fins in a cryopump have a large surface area?

• Larger surface area provides more room for trapping air molecules, which improves pumping.
• Large surface area reduces the noise of the pump.
• Large surface area reduces vibrations.

Q3. A cryopump will eventually become saturated with air molecules and pumping efficiency will degrade.

• True. A saturated cryopump must undergo a process called regeneration to remove trapped air molecules and regain its original pumping efficiency.
• False. A cryopump can pump indefinitely and will never become saturated with air molecules.

Q4. Why is a vacuum chamber typically kept under vacuum when not in use?

• It saves electricity