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Visualization for Active learning: Understanding Nanomachines. CLT Exemplars. By Adham Ramadan Department of Chemistry Flash animations by Reham Tallawi CLT. Scope. “Nano” science and technology is one of the most rapidly developing areas in scientific research today.
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Visualization for Active learning: Understanding Nanomachines CLT Exemplars By Adham Ramadan Department of Chemistry Flash animations by Reham Tallawi CLT
Scope “Nano” science and technology is one of the most rapidly developing areas in scientific research today. A particular interest within this area is concerned with “nano” machines. However, the notion of how they operate can be challenging to conceptualize, particularly with regards to their motion. Visual learning objects can be very useful in this regard.
The “Nano" Dimension • “Nano” meter = 10-9 meter = 10-6 mm i.e. a 1/1,000,000 of a mm A human hair is 10-5 m (10,000 nm) thick
1960s 1980s 1950s 1970s 1990s Time Line 18th & 19th centuries 4th century 1661 1908 Roman glass containing nano metallic clusters Development of photography based on emulsions of silver halides, with photochemical reactions resulting in Ag nanoparticles composing the pixels of the image Mie publishes a paper explaining the dependence of glass colour on metallic clusters size and type 1970s: Fabrication of 2D quantum wells at Bell and IBM labs • 1990s: • Fabrication CNTs • “Discovering” superconductivity & ferromagnetism in C60 structures • Growing research in self assemblies • Widespread use of STM and AFM • Research in inkjet lithography • Mid 1990s: Widespread recognition of full potential of nanotechnology and realization of its interdisciplinary nature Boyle suggests the existence of corpuscles “minute masses / clusters that are not easily dissipable into particles that compose them” 1960: Feyman’s lecture to the American Physical Society speculating on possibilities & potentials of nano sized materials • 1980s: • Fabrication of metallic clusters using laser in 1981 • Synthesis of Fullerene in 1985 • Development of 1st nanomachine • Development of techniques for synthesizing and observing nanostructures (laser techniques, electron beam lithography, STM) • Observing of some of the special properties of nanoparticles 1950s & 1960s: Experimental activities on inorganic nano particles
Nanomachines • A machine is an assembly of interconnected components arranged to transmit or modify force to perform useful work Collins English Dictionary • A “nanomachine” is one which does that on the nano dimension
Nanomachines: What they are not!
Nanomachines:What they are Nanomachines are atomic and molecular assemblies which have been “constructed” to perform organized work/motion at the nano-scale, which is analogous to that on the macro-scale. Ellenbogen J.C., Love J.C. in Handbook of nanoscience and Technology, Goddard W.A. , Brenner D.W., Lyskevski S.E., Lafrate G.J., eds, CRC Press, 2002, 7-12. Vicario J., Meestma A., Feringa B.L., Chem. Comm., 2005, 5910-5912
Nanomachineswhy are they so exciting? • They represent a scientific curiosity and and experimental challenge at this development phase. • Possible immediate applications: • Medial technology: diagnosis as well as targeted drug delivery • Sensor technology: toxicological sensors • Envisaged future applications: • “Bottom-up” building of novel devices: used as components for building more ellaborate devices on these small scales.
NanomachinesReporting on their motion • This is usually carried out in publications through textual descriptions + 2 D diagrams. • This is effective in relaying information about WHAT LEADS to their motion. • However it is not effective in relaying a clear picture of the actual motion.
Hydrogen peroxide Oxygen + Water (H2O2) O2 + H2O Nanorods movement paths ExamplesSelf-propelled nanorods: a nano-submarine • Nano-rods of Platinum and gold. • Catalytic decomposition of hydrogen peroxide to generate oxygen gas on the Pt side causes the motion, pushing the platinum part forward. • Motion is due to the change in polarity of the liquid around the nano-rod and the interaction of the gold surface with it. • Paxton, W.F., Kistler, K.C., Olmeda, C.C., Sen, A., St. Agenlo, S.K., Cao, Y., Mallouk, T.E., Lammert, P.E., Cresi, V.H., J. Am. Chem. Soc., 2004, 126, 13424-13431. • Fournier-Bidoz, S., Arsenault, A.C., Manners, I., Ozin, G.A., Chem. Commun., 2005, 441-443.
ExamplesA nano bio-machine: a nano-locomotive • Kinesin is a “motor” protein which can move along filamentous structures called microtubules. • Kinesin has two “head” which alternately undergo a chemical reaction that releases them, then re-attaches them to the microtubule. • Kinesin is fixed to a glass surface with its heads pointing upward. • A microtubule can then move on these heads due to the chemical reaction. • The microtubule carries enzymes which generate the chemicals needed for the reaction, i.e. a source for its own “fuel”. • Vale, R.D., Milligan, R.A., Science, 2000, 288, 88-95. • Du, Y.Z., Hiratsuka, Y., Taira, S., Eguchi, M., Uyeda, T.Q.P., Ymoto, N., Kodaka, M., Chem. Comm., 2005, 2080-2082.
Real images of a nano car moving ExamplesThe nano-car • These are single organic molecules synthesized with 4 bucky balls (C60). • When placed on a gold surface, and heated, the C60 roll on the surface • The bucky balls move independently, allowing the turning and pivoting of the nano-car. • Shirai, Y., Osgood, A.J., Zhao, T., Kelly, K.F., Tour, J.M., Nano Lett., 2005, 5, 2330-2334.
Examples (Again!)Self-propelled nanorods: a nano-submarine • Nano-rods of Platinum and gold. • Catalytic decomposition of hydrogen peroxide to generate oxygen gas on the Pt side causes the motion, pushing the platinum part forward. • Motion is due to the change in polarity of the liquid around the nano-rod and the interaction of the gold surface with it.
Examples (Again!) A nano bio-machine: a nano-locomotive • Kinesin is a “motor” protein which can move along filamentous structures called microtubules. • Kinesin has two “head” which alternately undergo a chemical reaction that releases them, then re-attaches them to the microtubule. An Animated Model for Processive Motility by Conventional Kinesin, Vale, R.D., Milligan, R.A., Johnson, G., http://www.scripps.edu/cb/milligan/
Examples (Again!) A nano bio-machine: a nano-locomotive • Kinesin is fixed to a glass surface with its heads pointing upward. • A microtubule can then move on these heads due to the chemical reaction. • The microtubule carries enzymes which generate the chemicals needed for the reaction, i.e. a source for its own “fuel”.
Examples (Again!) The nano-car • These are single organic molecules synthesized with 4 bucky balls (C60). • When placed on a gold surface, and heated, the C60 roll on the surface • The bucky balls move independently, allowing the turning and pivoting of the nano-car.
Examples (Again!) The nano-car http://www.rice.edu/media/nanocar.html
Student Feedback • Animations, as visual learning objects, are very useful for demonstrating movement. • They are best as complementing text or narrative explanation. • They are most useful for complex cases difficult to demonstrate using 2D diagrams and textual description. • They are most effective as learning objects when offered after the challenge of textual description and 2 D diagrams. In these cases they are effective because they clarify ambiguities and/or confirm ideas. • They are useful for group learning as they ensure that all develop a similar understanding. • They have the drawback of possibly being limiting to the imagination.
Sources for images (in order of appearance in slides) • http://www.acewigs.com/shop/wigs/Jacquelyn_Wigs/13687_pop.php • http://www.pbase.com/overney/ • http://atlas.geo.cornell.edu/people/weldon/maps2.html • http://www.brooklyn.cuny.edu/bc/ahp/LAD/C4c/C4c_carbon_forms.html • http://mc.clintock.com/basement/tool_area/dewalt_drill.php • http://www.threadgrind.com/worm.asp • http://www.wfrfire.com/website/front/index.htm?/website/rescue/SAWS/k2300_elect.htm&front • http://www.empcorp.com/html/products/advanced/thermalManagement/electricFan.asp • http://www.deviantart.com/deviation/1941013/