Top-down approaches

Bottom-up approaches

Read and translate the texts.

These seek to arrange smaller components into more complex assemblies.

· DNA nanotechnology utilizes the specificity of Watson–Crick basepairing to construct well-defined structures out of DNA and other nucleic acids.

· Approaches from the field of "classical" chemical synthesis also aim at designing molecules with well-defined shape (e.g. bis-peptides).

· More generally, molecular self-assembly seeks to use concepts of supramolecular chemistry, and molecular recognition in particular, to cause single-molecule components to automatically arrange themselves into some useful conformation.

These seek to create smaller devices by using larger ones to direct their assembly.

· Many technologies that descended from conventional solid-state silicon methods for fabricating microprocessors are now capable of creating features smaller than 100 nm, falling under the definition of nanotechnology. Giant magnetoresistance-based hard drives already on the market fit this description, as do atomic layer deposition (ALD) techniques. Peter Grünberg and Albert Fert received the Nobel Prize in Physics for their discovery of Giant magnetoresistance and contributions to the field of spintronics in 2007.

· Solid-state techniques can also be used to create devices known as nanoelectromechanical systems or NEMS, which are related to microelectromechanical systems or MEMS.

· Atomic force microscope tips can be used as a nanoscale "write head" to deposit a chemical upon a surface in a desired pattern in a process called dip pen nanolithography. This fits into the larger subfield of nanolithography.

· Focused ion beams can directly remove material, or even deposit material when suitable pre-cursor gasses are applied at the same time. For example, this technique is used routinely to create sub-100 nm sections of material for analysis in Transmission electron microscopy.

4. Compare two columns of words and find Russian equivalents (from the right column) to the following English words (from the left one):

1. организовывать молекулы в полезные структуры	a. to fall under the definition of nanotechnology
2. получать Нобелевскую премию по физике	b. to be related to microelectromechanical systems
3. относиться к электромеханическим системам	c. to arrange molecules into useful conformation
4. организовывать меньшие компоненты в более сложные	d. to construct structures out of DNA and nucleic acids
5. создавать структуры из ДНК и нуклеиновых кислот	e. to receive the Nobel Prize in Physics
6. создавать меньшие материалы посредством использованиябольших	f. to arrange smaller components into more complex
7. попадать под определение нанотехнологии	g. to create smaller devices by using larger ones

5. Insert the prepositions into the following sentences:

1) Bottom-up approaches seek to arrange smaller components … more complex assemblies.

2) DNA nanotechnology utilizes the specificity … Watson–Crick basepairing to construct well-defined structures … … DNA and other nucleic acids.

3) Approaches … the field of "classical" chemical synthesis also aim … designing molecules … well-defined shape

4) Molecular self-assembly seeks to use concepts … molecular recognition to cause single-molecule components to automatically arrange themselves … some useful conformation.

5) Top-down approaches seek to create smaller devices … using larger ones to direct their assembly.

6) Peter Grünberg and Albert Fert received the Nobel Prize … Physics … their discovery … Giant magnetoresistance and contributions … the field … spintronics … 2007.

7) Atomic force microscope tips can be used … a nanoscale "write head" to deposit a chemical … a surface … a desired pattern.

6. Answer the following questions:

1) What does Bottom-up approach seek?

2) What does molecular self-assembly use concepts molecular recognition for?

3) What is top-down approach?

4) What did Peter Grünberg and Albert Fert receive the Nobel Prize in Physics for?

5) What is nanolithography?