CLT Exemplars

Visualization for Active learning: Understanding Nanomachines

ByAdham 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

The “Nano" Dimension

Time Line4th century 1661

Roman glass containing nano metallic clusters

Boyle suggests the existence of corpuscles “minute masses / clusters that are not easily dissipable into particles that compose them”

18th & 19th centuries

Development of photography based on emulsions of silver halides, with photochemical reactions resulting in Ag nanoparticles composing the pixels of the image

1908

Mie publishes a paper explaining the dependence of glass colour on metallic clusters size and type

1950s 1970s 1990s1960s 1980s

1950s & 1960s: Experimental activities on inorganic nano particles

1960: Feyman’s lecture to the American Physical Society speculating on possibilities & potentials of nano sized materials

1970s: Fabrication of 2D quantum wells at Bell and IBM labs

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

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

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

• 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.

Nanomachineswhy are they so exciting?

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.

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.

Nanorods movement paths

Hydrogen peroxide Oxygen + Water (H2O2) O2 + H2O

• 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.

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.

Real images of a nano car moving

• Shirai, Y., Osgood, A.J., Zhao, T., Kelly, K.F., Tour, J.M., Nano Lett., 2005, 5, 2330-2334.

Understanding Nanomachines in Motion I

Feedback

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!)Self-propelled nanorods: a nano-submarine

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

Understanding Nanomachines in Motion II

Feedback

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.

Conclusions

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/