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Check Your Understanding

The following questions accompany this lesson. The answers are given below each question. To reveal an answer, place the cursor over "REVEAL THE ANSWER".

1. What is a nanometer?
   
   
   A nano unit is 10^-9 meters.

2. Why is it important to study material at the nanoscale?
   
   
   Materials behave differently at the atomic level. Some conduct electricity better, while others are better at absorbing heat. By manipulating materials at the nanoscale, we are able to use these new properties to design products that are stronger and more efficient.

3. Describe “grey goo”.
   
   
   Grey goo refers to self-replicating nanobots malfunctioning and taking over the earth. Grey goo is not a possible risk of current nanotechnologies.

4. Why is carbon such a special element?
   
   
   Carbon is abundant, and it can form four covalent bonds to other elements or itself, forming chains and rings.

5. List three current applications of nanotechnology.
   
   
   Sunscreen, sports gear, and clothing.

6. What are quantum dots?
   
   
   Quantum dots are nanoparticles that are semiconductors. Their behavior is between regular bulk semiconductors and individual molecules.

7. Describe how nature works at a nanoscale.
   
   
   In nature, geckos have super-fine hairs on their feet that allow them to walk on walls. In our bodies, we have cellular machines that are nanoscale.

Exercise Your Brain

1. Read the article Marine Sponges Provide Model for Environmentally Friendly Nanoscale Materials Production, Report Scientists at UC Santa Barbara and answer the following questions:

1. Why is silicon important in sponges, and why is silicon of interest to humans?

2. What do the sponge’s glass needles contain that controls the synthesis of the needles, and why is it so important?

3. Why is the production of these materials termed environmentally friendly?

4. Summarize the article, and discuss how these sponges have taught scientists about nanotechnology.

1. Silicon is a component of the glass needles that sponges use to construct a sort of skeleton. Silicon can be used in computers, telecommunication devices, and other devices.

2. The sponge’s glass needles contain a filament of protein. This protein is especially important because it acts as a catalyst – which is new because no proteins have been found to serve as catalysts in the formation of biominerals.

3. These sponges are able to manufacture these materials efficiently at a low temperature. This is important because normally these materials are produced at high temperature, in vacuums, and with harmful chemicals.

4. The researchers discovered that the sponges produce large quantities of fine glass needles made from silicon and oxygen. The protein catalyst or enzyme that the sponges use to do this acts as a template that shapes the glass filaments as they grow. An understanding of the production of these needles can be applied to the synthesis of semiconductors and metal oxides that have photovoltaic and semiconductor properties.

2. Read the short article Researchers Discover Materials Retain Useful Properties at Nanoscale and answer the following questions:

1. What material did the scientists look at, and what was their finding?

2. What is a ferroelectric material?

3. Describe some differences the scientists found between barium titanium oxide at the nanoscale and bulk scale.

1. They looked at barium titanium oxide, and discovered that it retains its property of energy conversion (electrical to mechanical) at the nanoscale.

2. Ferroelectric materials have a spontaneous dipole (separation of charges) that allows them to generate an electric current when their shape is changed.

3. They found that converting electricity to mechanical energy is less efficient at the nanoscale. They also found that the dipoles align differently at the nanoscale and the bulk counterpart.

3. Research how nanotechnology can be applied in medicine. Come up with lists of current applications, applications that are likely to be available in the near future, and those applications that may be available in the more distant future. What basic scientific research questions must be answered before possible future applications could become a reality?