Nanotechnology

Arrangements of atoms determine some physical properties of those elements. 

1 nanometer = 1 billionth of a meter = 5 atoms

Nanotechnology is the manipulation of matter at the atomic and molecular levels (between 1-100 nanometers in size). 

Scanning Tunneling Microscope

• Able to observe and move atoms around
• Since atoms tend to attract each other, they can be engineered using this device

Application: Silicon Wafers

• Used in phones, laptops, cars, etc

• Transistors made of silicon are wired together in circuits to control electrical signals
• At nanoscale transistors lose their functionality
• Fin Field-Effect Transistors are very thin transistors (6 nanometers wide) that makeup silicon wafers
• Lithography: coat silicon wafer with a polymer → put a mask on it → shine a light through it → size of mask and wavelength of light determines features of the wafer

Application: Quantum Dots

• Small cluster of atoms ranging from 2-10 nanometers
• Because of quantum confinement, the bandgap of material depends completely on the size of the material once size reaches sub-15 nanometers
• Uses cases: diode lasers, displays, pharmaceuticals

Application: Carbon Nanotube

• Rolled up graphene that’s lightweight, strong, and conducts electricity/heat
• One atom thin → very responsive to the environment → use cases in diagnostics
• To make nanotubes: deposit nanocrystals on a surface → conduct chemical vapor deposition → flow in a carbon source → carbon dissolves the nanocrystals → nanotubes precipitate out of them in tubes → extract the right ones from this pile of nanotubes
• Applications: energy storage, device modeling, automotive parts, boat hulls, sporting goods, water filters, thin-film electronics, coatings, actuators, electromagnetic shields, etc

Application: Bacteriophages

• A virus with DNA made up of single-stranded DNA and proteins
• M13 bacteriophage is long and thin (880 nanometers in length, 9 nanometers in diameter)
• Cut the M13 with a DNA scissor and insert a new piece of DNA that randomly codes for a protein
• Next time the virus is replicated within a bacterial host, a new short protein sequence is produced on the coat
• This allows the virus to build iron phosphate for battery electrode material, cad sulfide for the semiconductor material, etc