Dna lithography copy

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  • 1. LITHOGRAPHY Lithography (from Greek - lithos, 'stone'+ - graphein, 'to write') is a method for printing using a stone (lithographic limestone) or a metal plate with a completely smooth surface.Invented in 1796 by German author and actor Alois Senefelder as a cheap method of publishing theatrical works, lithography can be used to print text or artwork onto paper or other suitable material.

2. DNA LITHOGRAPHY As the name indicates, DNA lithography refers to lithographyusing DNA. DNA strands of greater lengths are chosen for fabricating on tosuitable substratum for lithography. This technology is used for making DNA based electronicchips for electronic equipments. This technology opens new angles and dimensions to the futureof electronic chips with nanoscale sizes and with better storage capacity. 3. WHY DNA FOR LITHOGRAPHY? The first reason is because of its size. DNA exists in the nanometer scale and using this, will help to makenanoscale lithography. The second reason is because of its binding specificity. DNA is made of nucleotides with four types of bases namely Purines (Adenine and Guanine) Pyramidines (Cytosine and Thymine). Adenine binds or pairs only with Thymine and Cytosine binds only with Guanine. This specificity helps for precise nanoscale dna lithography. 4. DNA nanotechnology uses the unique molecularrecognition properties of DNA and other nucleic acids to create self-assembling branched DNA complexes with useful properties. DNA from DNA origamy is used for DNAlithography. DNA is thus used as a structural material rather than as a carrier of biological information, to make structures such as two-dimensional periodic lattices . 5. How DNA lithography works: Uses genetically engineered strands of DNA from algae or other simple organisms. These strands form very specific patterns by copying themselves onto substrate, based on the genes encoded in them. Strands that attached to the substrate are then coated with semiconductors or metals through a chemical process. A multitude of transistors is created in a step 6. THROUGH THE HISTORY 40 years ago: double patterning photolithography. 10 years ago: e beam lithography. Today: dna litography.Reasons 1. it requires lesser steps. 2. it need not require controlled steps. 3.usually organisms with lesser gene encoded in to their dna is suitable for lithographical methods. 7. DNA LITHOGRAPHY DNA ORIGAMIdesign of DNA molecules that readily fold into arbitrary shapes DNA origami holds promise for the bottom-up fabrication of nanoscale devices, both through DNAdirected self-assembly and nanopatterning processes. The patterning of inorganic substrates with DNA templates usually requires the deposition of intermediate . 8. Low concentrations of triangular DNA origami are binding to wide lines on a lithographically patterned surface. 9. Procedure for making nano-scale electronic components Using dna lithography Specifically synthesized DNA strand with tailed ends 10. Procedure for making dna lithographic moleculeProteins applied to the ends, different proteins applied to the center 11. Using DNA Lithography, complex structures can be created DNA probe DNA Resistordna transistorDNA Inductor 12. Top down lithographyRockStatue 13. Building something by starting with a largercomponent and carving away material (like a sculpture) . In nanotechnology: patterning (using photolithography) and etching away material, as in building integrated circuits. Top-down lithography is a process by which electrical circuit elements on a silicon wafer are constructed by cutting and etching, and is currently used to make semiconductor chips. 14. Bottom up lithographyBrickBuilding 15. Building something by assembling smallercomponents (like building a car engine), atom by atom assembly. In nanotechnology: self-assembly of atoms and molecules, as in chemical and biological systems. Bottom-up self-assembly is a process in which molecules and/or nanoscale materials are selfassembled into desired structures using chemical bonds or various similar interactions. 16. DNA LITHOGRAPHY CURRENT TRENDS I.DNA nanotechnology is an area of current research that uses the bottom-up, self-assembly approach for nanotechnological goals.II.The specificity of the interactions between complementary base pairs make DNA a useful construction material through design of its base sequences) and three-dimensional structures in the shapes of polyhedra.III. These DNA structures have also been used to template the assembly of other molecules such as gold nanoparticles and streptavidin proteins (bacteria uses are the purification or detection of various biomolecules. 17. DNA ORIGAMY DNA origami is the nanometer scale folding of DNA tocreate arbitrary two and three dimensional shapes at the nanometer scale. The specificity of the interactions between complementarybase pairs make DNA a useful construction material, through design of its base sequences. Developed by Paul Rothemund at the California Institute ofTechnology, the process involves the folding of a long single strand of viral DNA aided by multiple smaller "staple" strands. 18. These shorter strands bind the longer in various places,resulting in various shapes, including a smiley face and a coarse map of China and the Americas, along with many three-dimensional structures such as cubes. To produce a desired shape, images are drawn with a rasterfill of a single long DNA molecule. This design is then fed into a computer program thatcalculates the placement of individual staple strands. 19. Each staple binds to a specific region of the DNA template,and thus due to Watson-Crick base pairing, the necessary sequences of all staple strands are known and displayed. The DNA is mixed, then heated and cooled. As the DNA cools, the various staples pull the long strandinto the desired shape. 20. Either electron beam or optical lithography are used to createarrays of binding sites of the proper size and shape to match those of individual origami structures. Designs are directly observable via several methods,including Electron Microscopy, atomic force microscopy, or fluorescence microscopy when DNA is coupled to fluorescent materials. 21. The DNA structure at left will selfassemble into the structure visualized by atomic force microscopy at right. 22. DNA ORIGAMI MEETS LOW-COST LITHOGRAPHY A study conducted in 2010 showed a new way for molecularlithography using DNA. Chemists in the US have developed an easy way to integratethe 'bottom up' assembly of DNA origami with the 'top down' patterning of low cost lithography. The method, which involves sticking pieces of DNA toprepositioned gold islands, might help researchers in their bid to use DNA origami for nano-electronics. 23. .The patterning of inorganic substrates with DNAtemplates usually requires the deposition of intermediate mask layers as these molecules are sensitive to common dry etching. . The design of DNA molecules that readily fold intoarbitrary shapes DNA origami holds promise forthe bottom-up fabrication of nanometer scale devices, both through DNA-directed self-assembly and nanopatterning processes. 24. ADVANTAGES The utility of this approach lies in the fact that thepositioned DNA nanostructures can serve as scaffolds, or miniature circuit boards, for the precise assembly of components such as carbon nanotubes, nanowires and nanoparticles at dimensions significantly smaller than possible with conventional semiconductor fabrication techniques. This opens up the possibility of creating functionaldevices that can be integrated into larger structures, as well as enabling studies of arrays of nanostructures with known coordinates. 25. : Advantages include: high resolution (6nm 22nm), efficient production (up to 10 timesmore cost-effective), ease of integration and use in arrays of elements. it is more efficient. It will be up to 10 times more cost-effective than current methods of mass production. Rapid manufacturing time 26. .Disadvantages of DNA Lithography Still a growing field, limited by current genetic engineering techniques 10 years until large scale production is possible Long process to create new patterns High start-up/research costs