Articles by: maz

Light Powered Motor and Experiment Vlogging

Most of you probably read the last issue of C&EN with the spiffy carrot loving cover story (good for me because I love carrots, but have never tried those ugly-looking BetaSweets). Inside, however, there was an extremely interesting little article in the “Science and Technology Concentrates” about light-driven pulleys turning a plastic motor.

Now photo mobile polymer materials have been around for quite a while, at least from my perspective seeing as how I wasn’t even in highschool when the big Nature paper came out. Some might remember the Nature 1999 Sep 9;401(6749):152-5 Koumura et al. paper titled “Light-Driven monodirectional molecular rotor”. Although back then, the rotation was monodirectional around a C-C double bond in a chiral, helical alkene. It was activated by UV light or a change in temperature and the motor was based on light-induced cis-trans isomerizations that caused 180 degree rotations followed by thermally controlled helicity inversions, which basically nullified half a rotation. Four isomerizations resulted in 1 complete cycle.

Well this was pretty darn cool but we’ve come a long way since then. As expected, and as Koumura said, structurally modified chiral alkenes played the central role in the development of these molecular motors that were beginning to interest the MEMS people (MEMS stands for Micro-Electromechanical Systems…I am pretty sure).

In J Am Chem Soc. 2003 Dec 10;125(49):15076-86, ter Wiel MK et al. introduced the worlds smallest artificial light-driven motor using 28 carbon atoms and 24 hydrogen atoms.

Reprinted with permission from American Chemical Society: Journal of the American Chemical Society (Nov. 2003).

It also had a dramatic speed increase over the original designs, at a whopping 18s half-life at the fastest step. Even if it wasn’t going to be turning any relevant loads any time soon, it was a dramatic improvement over the original concept 4 years earlier. Still, even though some clever O-chem tricks made the motor better, it still operated on the same 4-step cycle that Koumura’s did back in 99′. Even recently, in Org. Biomol. Chem., 2008, 6, 507 – 512, DOI: 10.1039/b715652a, Pollard et al. report on substituting naphthalene moieties for phenyl moieties, in order to better control the speed of the motors, and to enable the design and synthesis of more complex systems.

Meanwhile, the MEMS people came up with interesting designs similar to this:

“A five micron wide resin structure, with a shape resembling a lawn sprinkler, rotates when illuminated by a laser beam. Tiny rotors like this one may someday power micromechanical systems (MEMS), or twist molecules to measure their mechanical properties.” Reported by: Péter Galajda; Pál Ormos, Applied Physics Letters, 8 January, 2001.

There was quite a bit of work done focusing on creating rotors that responded to laser light, although the practical applications of such devices aren’t as numerous as the devices that…well don’t require a coherent, collimated, polarized light beam to operate. Or at least they weren’t until Peidong Yang’s came around with his nanolasers.

Unfortunately, all of these motors share the drawback of being unidirectional. It was until recently, with Ikeda’s et al. paper in Angew. Chem. Int. Ed. 2008, 47, 4986, that a very cool and new method for directly converting light into mechanical work. Basically they drew on the fact that azobenzene derivatives, when incorporated into liquid crystals, can have an isotropic phase transition induced isothermally by irradiation with UV light to cause trans–cis photoisomerization, and that the reverse transition can be induced by irratiation with visible light to cause cis-trans back-isomerization. This photoinduced phase transition
led to successfully reversible deformations of liquid crystal elastomers containing azobenzene chromophores just by changing the wavelength of the incident light.

Now this by itself doesn’t a motor make. There was one large problem: the liquid crystal elastomer had to be made into a film or “belt” for a motor. However, the LCE film by itself wasn’t mechanically strong enough and tended to crack after short light irradiation at high intensities. So to fix this issue, they simply laminated the LCE film with flexible polyethylene sheets. I love this type of simple solution to what could have been a convoluted problem. This is very much like what Mitch and I tend to do.

*Note that they did do a study of increasing light intensity and it’s correlation to the mechanical force generated by the film. They found that “the maximum force and the increment rate of the generated force are enhanced with an increase of the light intensity.”*

So what happened? Well check this out:

Thats right. That is an actual light-driven motor NOT on the micro-scale. The diameter of those pulleys are 10mm on the left and 3 mm on the right. Sure it isn’t going to be competing in any races at the moment, but it could still be amazingly useful in the future. Light, straight to DC? That would be pretty darn awesome.

PS. Tomorrow is the first day of the experiment Mitch and I are running. Since we can, we will be broadcasting the first live cyclotron experiment out over the interweb. This may be one of the first live nuclear physics experiments broadcasted. Other then that, it is just cool. SO we will have it up all 24 hours as a “live vlog”.

Feel free; hell feel obligated to stop by, leave a comment, chat, ask questions, offer constructive or destructive criticism, whatever. Maybe ACS will pick this up as a new way to present new research: present it as it happens! Live!!!

Wanted (the movie)

So I know that this doesn’t qualify as a chemistry post, but it’s still pretty darn cool.

Earlier today, Mitch scored some free pre-screening tickets for a movie called Wanted with Angelina Jolie in it.  There was some white guy in it too, as the main character, but I didn’t really know or care who he was.  In fact, I had no idea what the movie was about until we went and saw it.  When Mitch told me that Angelina Jolie was in it, I accepted the invitation.

So he got the tickets through Techcrunch, a blog that focuses on reviewing new tech. products (mostly internet products) and companies.  It was a first come first serve sort of contest and Mitch happened to log onto their website just it was posted.  He got two tickets, and we drove out to the Metreon theater San Francisco.

We get there and get in line, and find out that there are about 250-300 ppl coming to see this prescreening.  Many people got their tickets through techcrunch, allowing us that always sweet line cut since they had a separate ticket check system.  The Myspace ppl, on the other hand, were stuck in line, cursing us as we went past.  I think I forgot to mention that the event was cosponsored by techcrunch and Myspace.

Seeing a movie in a prescreening is pretty darn cool.  It was kinda like going to see a movie at the opening show.  The whole crowd gets into it and sort of participates in the movie.  Apparently there is a sort of “movie prescreen” subculture as evidenced by the fact that many of the movie goers knew each other from other prescreens and were discussing the latest events; some bemoaning their inability to secure Wally prescreen tickets.

Anyways, the movie itself was really freaking cool.  It is a super action, fast-paced thriller i guess with some cheese, cool music, and a light attitude.  It wasn’t all serious, which would have totally ruined the movie.  Both Mitch and I were amazed to find ourselves actually liking the movie a lot, and I see it becoming a total guy movie-night classic.

Also cool, was that I came home and watched the daily show only to find James McAvoy (the name of the main character) as the guest.  Apparently he has heavy scottish accent that.  During the movie though, I had no idea that he wasn’t American.  I guess he is a pretty good actor.

So yeah, that’s my movie pitch.  After seeing one of the most entertaining, if not really interesting, movies I have seen in a looong time, I had to go and blabber about it.  Another bonus was of course seeing Angelina Jolie looking oh-so gorgeous again.

Heh, and I saw a lot of other ppl blogging or talking about blogging about it, so I had to add my two cents.

By June 23, 2008 4 comments Uncategorized

From ACS New Orleans

Hey there, from New Orleans! ACS 2008 kicked off today with the early morning registration rush that is required for every ACS meeting. This one, however, was awesomely bad, as the organizers, displaying true ig-nobel prize worthy genius, nearly caused an uprising from the mob of chemists waiting for their ID-cards.

So here’s what happened. Around 8 in the morning, chemists of all sorts spilled into the registration hall at the convention center in the French quarter of New Orleans. To register for the conference, each person had to first enter their information into the onsite computers, pay a fee, and then go collect the printed out ID cards. The first part of this procedure went fine, and it took only minutes for myself, Mitch, and Noel to pay the registration fee and get in line for the ID card. However, the wait for picking up the admission badge is where everything went haywire.

Instead of intelligently placing the printers next to the ID card readers so that new registrees could grab their papers and assemble their own ID’s, the organizers decided to have 3 printing stations where the ACS hosts would carefully complete the complicated task of folding the papers in half, inserting them into a plastic holder, and lacing an ACS lanyard through the tag.

One particularly loud lady, the “supervisor” – we were told so by other employees who refused to accept responsibility of the brewing crisis- especially endeared herself to the crowd. After waiting 20 minutes or more to reach the front of said printing line, the self-proclaimed “lady in red” was…well, let me paint the picture for you.

Imagine yourself, after waiting for what has felt like hours of standing in a much too long line, checking your watch every few minutes because your chance to hear about element 108 and the plans to make 120 is literally ticking away. Finally you begin to reach the front of the line: you can hear names being called and briefly think about how nice it would be to get your tag. But wait…something is wrong. You hear people’s names called, followed by groans, moans and subdued protests. Thats not right…you think to yourself. Then you hear the words that make you hope…no pray, that this little “lady in red” does not call your name.

“John Blahblah!”

“Yeah, here!”

“Sir, Back of the line please!”


“Sir, Back Of The Line.”

And there it is. The bottle-neck in the registration process that eventually led to this:

Mitch Crowd Managing

was caused by the assumption that chemists can’t make their own nametags. Yes, the above picture is Mitch becoming an honorary ACS crowd manager as he hands out the plastic ID card holders to near-unruly chemists. Although, I probably didn’t help the situation by loudly telling people not to budge if told to move to the back of the line. What can I say…I am just a rebel.

So Kudos to the ACS event organizers. The first few hours of the first day of the conference was a complete hash, a prime example of how NOT to manage a huge national conference’s registration. For all those unfortunate chemists who missed the morning talks, or decided to forgo the idiotic ID to actually attend those talks, or were just generally upset by the morning’s administrative malfunctions, I hope you comment on this post. Or just comment if you find it funny. Or if you want to make fun of me. Whatever.


By April 6, 2008 4 comments Uncategorized

IG Nobel Prizes

So after the Physics Nobel Prize Post, I felt it would be necessary to point these out as well. For those of you who don’t know what the IG Nobel Prizes are…well, I think you’ll figure it out.

Oh, one last thing. These are all awarded by The Annals of Improbable Research, which is an institution like (heh, sort-of) The Royal Swedish Academy of Sciences which awards the Chemistry and Physics Nobels, or the The Norwegian Nobel Institute which awards the Peace Nobel.

Here we go:

Brian Witcombe of Gloucester, UK, and Dan Meyer of Antioch, Tennessee, USA, for their penetrating medical report “Sword Swallowing and Its Side Effects.”
REFERENCE: “Sword Swallowing and Its Side Effects,” Brian Witcombe and Dan Meyer, British Medical Journal, December 23, 2006, vol. 333, pp. 1285-7.
WHO ATTENDED THE CEREMONY: Brian Witcombe and Dan Meyer

L. Mahadevan of Harvard University, USA, and Enrique Cerda Villablanca of Universidad de Santiago de Chile, for studying how sheets become wrinkled.
REFERENCES:”Wrinkling of an Elastic Sheet Under Tension,” E. Cerda, K. Ravi-Chandar, L. Mahadevan, Nature, vol. 419, October 10, 2002, pp. 579-80.
“Geometry and Physics of Wrinkling,” E. Cerda and L. Mahadevan, Physical Review Letters, fol. 90, no. 7, February 21, 2003, pp. 074302/1-4.
“Elements of Draping,” E. Cerda, L. Mahadevan and J. Passini, Proceedings of the National Academy of Sciences, vol. 101, no. 7, 2004, pp. 1806-10.
WHO ATTENDED THE CEREMONY: Lakshminarayanan Mahadevan, and Enrique Cerda Villablanca’s sister Mariela.

Prof. Dr. Johanna E.M.H. van Bronswijk of Eindhoven University of Technology, The Netherlands, for doing a census of all the mites, insects, spiders, pseudoscorpions, crustaceans, bacteria, algae, ferns and fungi with whom we share our beds each night.
REFERENCES: “Huis, Bed en Beestjes” [House, Bed and Bugs], J.E.M.H. van Bronswijk, Nederlands Tijdschrift voor Geneeskunde, vol. 116, no. 20, May 13, 1972, pp. 825-31.
“Het Stof, de Mijten en het Bed” [Dust, Mites and Bedding]. J.E.M.H. van Bronswijk Vakblad voor Biologen, vol. 53, no. 2, 1973, pp. 22-5.
“Autotrophic Organisms in Mattress Dust in the Netherlands,” B. van de Lustgraaf, J.H.H.M. Klerkx, J.E.M.H. van Bronswijk, Acta Botanica Neerlandica, vol. 27, no. 2, 1978, pp 125-8.
“A Bed Ecosystem,” J.E.M.H. van Bronswijk, Lecture Abstracts — 1st Benelux Congress of Zoology, Leuven, November 4-5, 1994, p. 36.
WHO ATTENDED THE CEREMONY: Dr. Johanna E.M.H. van Bronswijk

Mayu Yamamoto of the International Medical Center of Japan, for developing a way to extract vanillin — vanilla fragrance and flavoring — from cow dung.
REFERENCE: “Novel Production Method for Plant Polyphenol from Livestock Excrement Using Subcritical Water Reaction,” Mayu Yamamoto, International Medical Center of Japan.
PRESS NOTE: Toscanini’s Ice Cream, the finest ice cream shop in Cambridge, Massachusetts, created a new ice cream flavor in honor of Mayu Yamamoto, and introduced it at the Ig Nobel ceremony. The flavor is called “Yum-a-Moto Vanilla Twist.”

Juan Manuel Toro, Josep B. Trobalon and Nuria Sebastian-Galles of Universitat de Barcelona, for showing that rats sometimes cannot tell the difference between a person speaking Japanese backwards and a person speaking Dutch backwards.
REFERENCE: “Effects of Backward Speech and Speaker Variability in Language Discrimination by Rats,” Juan M. Toro, Josep B. Trobalon and Nuria Sebastian-Galles, Journal of Experimental Psychology: Animal Behavior Processes, vol. 31, no. 1, January 2005, pp 95-100.
WHO ATTENDED THE CEREMONY: The winners could not travel to the ceremony, so they instead delivered their acceptance speech via recorded video

of Blaxland, Blue Mountains, Australia, for her study of the word “the” — and of the many ways it causes problems for anyone who tries to put things into alphabetical order.
REFERENCE: “The Definite Article: Acknowledging ‘The’ in Index Entries,” Glenda Browne, The Indexer, vol. 22, no. 3 April 2001, pp. 119-22.

Brian Wansink of Cornell University, for exploring the seemingly boundless appetites of human beings, by feeding them with a self-refilling, bottomless bowl of soup.
REFERENCE: “Bottomless Bowls: Why Visual Cues of Portion Size May Influence Intake,” Brian Wansink, James E. Painter and Jill North, Obesity Research, vol. 13, no. 1, January 2005, pp. 93-100.
Mindless Eating: Why We Eat More Than We Think, Brian Wansink, Bantom Books, 2006, ISBN 0553804340.

Kuo Cheng Hsieh, of Taichung, Taiwan, for patenting a device, in the year 2001, that catches bank robbers by dropping a net over them.
REFERENCE: U.S. patent #6,219,959, granted on April 24, 2001, for a “net trapping system for capturing a robber immediately.”

If that crap can get patented…Mitch, I think we need to revist that patent.

Patricia V. Agostino, Santiago A. Plano and Diego A. Golombek of Universidad Nacional de Quilmes, Argentina, for their discovery that Viagra aids jetlag recovery in hamsters.
REFERENCE: “Sildenafil Accelerates Reentrainment of Circadian Rhythms After Advancing Light Schedules,” Patricia V. Agostino, Santiago A. Plano and Diego A. Golombek, Proceedings of the National Academy of Sciences, vol. 104, no. 23, June 5 2007, pp. 9834-9. WHO ATTENDED THE CEREMONY: Diego A. Golombek

And My Personal Favourite (remember, this is for the PEACE prize):

The Air Force Wright Laboratory, Dayton, Ohio, USA, for instigating research & development on a chemical weapon — the so-called “gay bomb” — that will make enemy soldiers become sexually irresistible to each other.
REFERENCE: “Harassing, Annoying, and ‘Bad Guy’ Identifying Chemicals,” Wright Laboratory, WL/FIVR, Wright Patterson Air Force Base, Ohio, June 1, 1994.

So take off your hats and raise your glasses to these brave and ignobel scientists, wasting our hard won funding, and pushing the very edge of our understanding of useless crap. Cheers.


By October 13, 2007 0 comments science news