CLT Exemplars Visualization for Active learning: Understanding Nanomachines

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

The “Nano" Dimension

Time Line

4 th century 1661 18 th & 19 th centuries 1908 1960s 1980s 1950s 1970s 1990s

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”

1950s & 1960s

nano particles Development of photography based on emulsions of silver halides, with photochemical reactions resulting in Ag nanoparticles composing the pixels of the image : Experimental activities on inorganic Mie publishes a paper explaining the dependence of glass colour on metallic clusters size and type

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 •

1990s

: •Fabrication CNTs •“Discovering” superconductivity & ferromagnetism in C 60 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 1980s

: •Fabrication of metallic clusters using laser in 1981 •Synthesis of Fullerene in 1985 •Development of 1 st nanomachine •Development of techniques for synthesizing and observing nanostructures (laser techniques, electron beam lithography, STM) •Observing of some of the special properties of nanoparticles

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

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.

Nanomachines are atomic and molecular been assemblies “constructed” which to have perform organized work/motion at the nano scale, which is analogous to that on the macro-scale.

Vicario J., Meestma A., Feringa B.L.,

Chem. Comm.

,

2005

, 5910-5912

Nanomachines why 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.

Nanomachines Reporting 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.

Examples

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.

Hydrogen peroxide



(H 2 O 2 )



Oxygen + Water O 2 + H 2 O

• 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.

Nanorods movement paths

Examples

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.

• • •

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.

Examples The nano-car

• • •

These are single organic molecules synthesized with 4 bucky balls (C 60 ).

When placed on a gold surface, and heated, the C 60 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.

Real images of a nano car moving

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 (C 60 ).

When placed on a gold surface, and heated, the C 60 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.ht

ml 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/SAW S/k2300_elect.htm&front http://www.empcorp.com/html/products/advanced/thermalManageme nt/electricFan.asp

http://www.deviantart.com/deviation/1941013/