Nanotech and MatScience Lecture 4

With decreasing the size of an object the ratio of inertial and viscosus force

• increases.
• decreases.

Superplasticity

• is a consequence of movements of dislocations.
• requires nanograins full with dislocations.
• is based on grain interface effects.
• allows elastic deformation

Nanowires

• can store Li thanks to the same crytal structure.
• are bandable due to disloacations.
• allows to form heterostructures not accessable in bulk form.
• of Si after delithiation fracture.

What is the typical thickness of a cell wall?

• ≈ 0.5nm
• ≈ 5nm
• ≈ 50nm
• ≈ 500nm

DNA origami is

• a self-assembly bottom up approach.
• based on evolution principle.
• allows to form 2 and 3D conductors.
• relies on hidrophobic interaction.

Phage display technique

• uses viruses to produce the desired molecule.
• is based on careful DNA design.
• results a large phage library.
• uses bio amplification.

Van der Waals interaction is

• based on hydrogen bonding.
• based on attraction between spontaneously induced dipols
• the cohesive force of cell wall.
• stronger than hidrogen bonds.

Gecko tape

• uses skin torn from the sole of the gecko.
• has good adhesive property due to hydrgen bonding.
• maximizes the area of touching surfaces.
• leaves residue on the surface.

Nanoscale catalysts are attractive since

• their surface/volume ratio scales with 1/radius ^2.
• nanosize could lead to novel chemical properties.
• they are less toxic.
• their production is cheaper.

Schockley–Queisser limit describes the efficiency

• of solar cells in general.
• of single pn junctions
• of single pn junctions illuminated by sun
• of pn junctions illuminated by sun with carrier multiplication.