Carbon nanotube based devices

1. Carbon nanotube based devices Presented By – RAJKUMAR MODAK Course coordinator- Dr. J. P. Singh Spinning Carbon nanotube

2. Carbon NaNotubes CNT: Rolling-up a grapheme sheet to form a tube . Large aspect ratio :length to diameter about 132000000 : 1 . Depending on the rolling angle and diameter the nanotube behaves as metal or semiconductor. CNT have strongest tensile strength and elasticity. Metallic CNT has very high current density(~ 10^9) which in 1000 times grater than cupper . Very good thermal conductor along tube length and insulator laterally tube axis. Conductivity 6000 W/m/K where cu has 385 W/m/K . Very good thermal stability - 2800ºC in vacuum and 750ºC in air . One dimensional transport – electron transport along axis only.

3. Applications Mechanical • building an elevator to space • CNT speakers Electrical • Field emission in vacuum electronics • Application in electrodes, capacitors • Energy storage • Lithium batteries • Hydrogen storage • Biological • sensors • DNA sequencing • AFM tips

4. Mechanical Applications : Elevator : • Nanotubes’ excellent strength to weight ratio creates the potential to build an elevator to space. Speakers : • Thin carbon nanotube films can • act as speakers • New generation of cheap, flat • speakers • Transparent, flexible, stretchable, • and magnet free

5. Electrical Applications : Field Emission Display (FED) • Uses electron beam to produce colour display. • Display screen is very slim and light compared to cathode ray tube display. NanotubeThermocell • Uses multiwalled CNT’s as electrode . • 3 times efficient then conventional . • Converts waste heat from industrial plants, pipes into electricity. Y- junction Devises • Y – Junction Nanotubes have potentials for diodes and transistors

6. Energy Storage Applications : Lithium Batteries • Nanotube’s have the highest revesable capacity of any carbon material . • Nanotube’s are outstanding material for Super capacitor electrodes . • They also have a number of properties like high surface area ,thermal conduvtivity that make them useful as electrode catalyst supports in polymer electrolyte membrane (PEM ) fuel cell . Hydrogen Storage • Single walled CNT can store hydrogen . • In future nanotube technology will meet the challenge of storing hydrogen and releasing them adequately in hydrogen fuel cell.

7. Biological Appllications: Sensors • NT’s has high absorption surface area . It’s electrical properties changes at room temperature in the presence of various gases. • It has very high sensitivity can detect very small concentration (ppm) of O2 , NO2 , NH3 etc . • CNT can be used as IR detector . • CNT are used as fore point probe arrengement to the masurement of resistivity for nano/micro size surfaces. DNA - Sequencing • NT’s fit into the grove of the DNA strand . • Apply of voltage across CNT – different DNA base-pairs give rise to different current signals. • With multiple CNT parallel fast DNA sequencing is passible. Top view and side view of the assembled CNT-DNA system

8. Biological Application s: • A critical component to the AFM • Determines the force applied to the sample • Fabricated from silicon Size • 100 – 200 microns long • 10 – 40 microns wide • 0.3 – 2 microns thick • Why do we use carbon nanotube probes ? • They are long and slender • They buckle • Has a small-end diameter • Have versatile carboxylic acid tips AFM tips

9. References • M.P. Anantram , F . Leonard – “ Physics of Carbon nanotube electronic devices ” , Reports on Progress in Physics , 69 ( 2006 ) , 507 – 561 . • MadhuMenon , Deepak Srivastava – “ Carbon nanotube based molecular electronic devices ” , Journal of Material Research , 23 May,1998 . • Yijing Fu , Qing Yu – “ Carbon nanotubes Theory and Applications ” , Institute of Optics , University of Rochester . • Y. Tzeny – “ Properties ,Characterization and Applications of Carbon Nanotubes ” , Auburn University , USA , July 2003 .

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