Graphene goes jiggly

So there’s a cool breakthrough in nanotechnology and electronics, yet I’ve not seen it widely reported for some reason.  On the plus side, this means my late posting is still fairly relevant news.  Korean researchers at Sungkyunkwan University and Samsung have managed to make the nano macro by growing a graphene layer on a 63 centimeter polyester sheet.  If you’re not entirely sure why that is a big deal, well, realize that until recently, one of the most popular methods of making graphene was continually peeling off bits of graphite with scotch tape until you managed to end up with a layer that is only an atom thick.  I’m not joking.  Google “scotch tape method” and although the first result is a Wikipedia page describing a way to diagnose some horrifying tapeworm infection, almost everything else you see is about graphene.  And since the wonderful Scotch tape brand does not come in giant meter sized sheets, you of understand why you don’t see huge hunks of graphene even though its synthesis is pretty understood.

Researchers from UT-Austin showed last year that you can grow graphene on sheets of copper by vaporizing carbon and letting the atoms settle onto the sheet.  The Korean team  took that one step further to get their graphene sheet.  They wrap a flexible copper foil around a cylinder in a furnace, and after the graphene was synthesized, the copper was rolled out and the graphene layer transferred onto a polyester base.

This is important for two main reasons.  First, there’s the fact that now all the synthesis and transfer is occurring on rolls.  Although the team obviously didn’t do it in their first investigation of this method, rolls enable mass production.  As team member Byung Hee Hong points out, roll processes usually allow for continuous films.  It’s very easy to have machines cycling sheets through rollers and transporting or transferring materials.  Think about newspapers.  The second reason this new research is important is the material they transferred the graphene onto.  Graphene itself is very flexible, but most synthesis methods don’t really let you take advantage of that because the graphene is grown on a brittle substrate.   This is why the UT-Austin research was a good stepping stone.  Copper is ductile and can be made into rolls.  Most other graphene substrates would not survive the process.  But the transfer to polyester is even more impressive because the polyester the team used was flexible and transparent.

The last bit is most exciting for applications.  Researchers have dreamed of making new innovative electronics with graphene, because it is very flexible, highly conductive, and almost completely transparent to optical wavelengths.  The polyester base doesn’t disrupt any of those properties.  To the curious, who wondered why Samsung was working on synthesizing graphene, that’s why.  Dreams of foldable electronics are one step closer to being realized with this research.  The lab’s first use of their graphene sheet was as a flexible touch screen.  Of course, other uses care less about the flexibility and more about the fact that you can get a huge sheet of graphene.  Before the technology to make flexible electronic becomes common, Hong mentions that large sheets would also be useful for making economic solar cells or large flat-panel displays.  Although it isn’t mentioned, I want to know if we could use this as a stepping to making graphene’s cousin, carbon nanotubes, more efficiently.  Carbon nanotubes are essentially rolled up graphene sheets, and research has shown you can actually make nanotubes by rolling up graphene nanoribbons).  So could we use this to make foot long nanotubes?  Because I really want to see a nanotube space elevator soon.

P.S. In other news, I dropped off the face of the Earth over the summer because I’m on the other side of the Earth.  I’m doing research in Japan through the NanoJapan program.  If you’re interested in hearing the cultural experiences of Rice scientists and engineers abroad, might I suggest you go here.

Rice Brain Awareness Week

This week, a new campus organization BRAiN: Building Rice Academics in Neuroscience is hosting Rice’s first annual Brain Awareness Week.  From Tuesday 3/9 to Saturday 3/13 there will be events each day focused on the variety and depth of neuroscience research taking place in the Texas Medical Center community and the benefits this basic research will have on each of our lives.  The schedule of events is as follows:

Tuesday March 9, 2010

Lab tour to Dr. David Eagleman’s Neuroimaging Lab at 4pm.

The tour can only accommodate 12 people on this tour. We will meet at the Sid Rich lobby at 3:30 pm and head over to BCM. If you know for sure you would like to come, please email brainclub09@gmail.com.

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Come buy BRAiN T-shirts at the RMC from 12pm – 2 pm! They are really awesome and are $10!

Wednesday March 10, 2010

Trivia Night: Brainiacs

8 pm at Kelly Lounge

Test your brain and win some fun prizes! There will be snacks!

Thursday March 11, 2010

Ethics of the Brain: The brain in a coma, persistent vegetative state, and locked in syndrome

8 pm Farnsworth Pavilion

Speaker: Dr. Joseph Kass; BCM assistant Professor of Neurology and Chief of Neurology Service at Ben Taub General Hospital

Guest Speaker: Dr. Jennifer Swindell; BCM Assistant Professor of Medicine and Medical Ethics with the Center for Medical Ethics and Health Policy

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Come buy BRAiN T-shirts at the RMC from 11 am – 1 pm!

Friday March 12, 2010

Movie Night: Requiem for a Dream (rated R)

8 pm at Herring 100

Learn about the biological and social basis of drug addiction and watch an amazing film! There will be snacks!

Saturday March 13, 2010

1st Annual Brain Awareness Week Lecture Series: Frontiers of Neuroscience

11 am – 2:30 pm at Farnsworth Pavilion (Please register here to guarantee free lunch)

Speakers:

- Dr. Michael Friedlander

Chair of Neuroscience Department at BCM

Individual cellular differences in plasticity behaviors within the visual cortex

- Dr. Mariella De Biasi

Neuroscience Department at BCM

Unveiling the mechanisms of nicotine addiction

- Dr. Joanna Jankowsky

Neuroscience and Neurology Department at BCM

How transgenic mice may help Generation Z avoid Alzheimer’s disease

- Dr. Wei Ji Ma

Neuroscience Department BCM

When perception goes wrong, and what it teaches us about the brain

- Dr. Steve Cox

Computational and Applied Mathematics, Rice University

Finding Hebbian Cell Assemblies in Large Neuronal Circuits

- Special Presentation by TaTGAP High School Students

This looks to be an exciting and informative week for students interested in learning more about neuroscience in general, or getting to know other students and faculty who also enjoy thinking about the brain.  As this is the first year these events are hosted at Rice, it is especially important to have a large amount of student involvement so that the administration is encouraged to continue pursuing options for a more concrete academic neuroscience program at Rice.

If you have any questions, please email brainclub09@gmail.com.  I will be in attendance at all these events, and I look forward to seeing you there.

(Full disclosure, I am a co-president of the organization hosting this event.)

The Decade in Review

So I’m a bit behind the ball, but I say review articles about the Aughts/Naughts/Double-ohs/Whatever-you’re-calling-the-previous-10-years are still acceptable any time in January.   We might not be living in the imagined 21st century of the 1950s with jetpacks and space stations, but a lot happened over the last 10 years in science and technology.  Ask 10 people to name the single biggest science event of the last decade and you’ll probably get 10 different answers (unless your sample is one research lab), but I think the following events will make it onto any list of the biggest breakthroughs from the Aughts. 

• Human Genome Project Completed (2000 – working draft published, 2003 – completed sequence published)
  • Technically a carry-over from the 1990s, the Human Genome Project represents one of the largest scientific collaborations ever.  The goal:  analyze the complete genetic code of a human.   The data could have unlimited applications.  On a practical side, biologists and doctors can start looking at genetic causes for diseases and how DNA controls biological functions.  But the genome can help scientists answer other intriguing questions about human biology.  Anthropologists and evolutionary biologists are already starting to look for genetic variations between ethnic groups to trace the history of human migration.  Going further back, we can look at evolutionary similarities between our genome and other creatures. 
• Mars Exploration Rovers (2004 – present)
  • Remember six years ago when Spirit and Opportunity landed on Mars?  Well they’re still working and are probably some of the greatest examples of what NASA can do.  Originally meant to perform a 90-day mission on the Red Planet, the rovers have greatly exceeded their expected lifespan and all scientific expectations.   Acting as robotic geologists, the rovers have analyzed the chemical composition of many different martian rock formations, enabling planetary scientists to figure out what drives geology on Mars.  The most exciting data suggests that much of Mars was once covered in water.  This coupled with observations from probes in orbit raise the possibility that water might still exist on Mars underground.  Armed with the evidence of water, NASA has said it will plan missions to look for evidence of life developing on Mars when it used to be significantly less red.
• Poincare Conjecture proven (2003 – proof published, 2006 – proof independently verified)
  • A somewhat antisocial person spending years on a ridiculously hard question?  No we’re not talking about how you and your friends worked on that last chemistry problem set.  We’re talking about eccentric mathematicians and a conjecture that hadn’t been proven for decades.  What is the Poincare conjecture?  Good question, and for those of without an understanding of topology and mathematical formalisms, we will let Wikipedia sum it up for us:  “ Poincaré wondered whether a 3-manifold [a four-dimensional equivalent of a solid] with the homology of a 3-sphere [the analog of a sphere in four-dimensions] and also trivial fundamental group had to be a 3-sphere. Poincaré’s new condition – i.e., ‘trivial fundamental group’ – can be re-phrased as ‘every loop can be shrunk to a point.’”   To get a feel for how epic proving the conjecture is, realize that it was proposed in 1904 and has turned out to be so hard to prove that it was included on the list of seven MilleniumPrize Problems (the prize being one million dollars per problem solved) and it took three years for anyone else to go through and verify that the proof was correct.  Almost as interesting as the actual proof was the drama surrounding it.  Grigori Perelman, the man who developed the proof, turned down the Fields Medal (the math equivalent of the Nobel pPrize) when he was awarded it.   After a bit of a dispute with one of the verifiers, Perelman has actually stopped working in mathematics.  He has also not taken any steps to obtain the reward for solving a Millenium Prize Problem, as Perelman has not published his proof in any peer-reviewed mathematics journal.
•  Large Hadron Collider complete (2008)
  • For a few weeks in the fall of 2008, everyone was a particle physicist as the world waited for the Large Hadron Collider to turn on.  And obviously, the world did not end with the test proton beam.  Unfortunately, the LHC had to stop after technical problems caused some of the focusing magnets to no longer work effectively.  It wasn’t until  November of last year that a test beam was run again, and experiments are scheduled to finally start in February.   One of the first questions physicists hope to answer is whether or not the Higgs boson exists, and if so, what is it mass.  In the current Standard Model of Particle Physics, the Higgs boson and Higgs field is responsible for giving all matter mass.   As the beam energy ramps up, CERN hopes to test other theories beyond the scope of the standard model and look at conditions not seen since the Big Bang.  If that’s a bit much to wrap your head around, might I recommend it in musical form?

These are just the first things that come to my mind.  There are certainly other equally important discoveries from the last decade that I forgot or neglected when writing this up.  Add your own favorite breakthroughs in the comments!

Rice Science in the News

So the other point of Catalyst blog is to detail interesting things going on with science and engineering and several interesting things happened this month within the hedges. I never meant to wait this long, but finals and holidays derailed any hope of nonessential work. So much belatedly, two cool things I’ve been meaning to write about.

First, one of Rice’s own just got major recognition. Dr. James Tour was ranked one of the ten most prolific chemists of the last decade by Times Higher Education.  The ranking was based on how many papers Dr. Tour has published and how often papers he was an author on are cited by other researchers.   With an average 62.76 citations per paper, Dr. Tour’s research is highly regarded.  Much of Dr. Tour’s research focuses on nanotechnology and crosses several disciplines; Tour is mainly a chemistry professor, but is also a professor of computer science and a professor of mechanical engineering and materials science (in fact, many professors who do research in nanotechnology have an additional appointment in materials science if they are from another department).   Nanotechnology seems to be a recurring theme in the Times list.  Counting Dr. Tour, four of the top ten chemists do research in nanotechnology, and another two do work in materials chemistry/science.  Once again, congratulations Dr. Tour. 

From the physics department, we have a surprising but predicted result from the physics department.  Dr. Randy Hulet’s atom cooling group has come up with experimental support for an interesting bit of quantum theory.  In the 1970s, Russian physicist Vitaly Efimov (a professor at the University of Washington) predicted that there could be quantumer trimers: systems where three particles are bound together in a quantum state.  Like the commonly referenced example of Borromean rings, the particles can only be bound if all three are present.   Hulet’s research page says that this happens because the interactions between two particles are so strong that the third particle actually causes the system to achieve a new equilibrium point.  Until this blogger takes quantum mechanics, that’s all I can really say about the nature of the system.  Efimov’s theory has two other interesting consequences.  One is that the trimer can form over a large range of sizes, with the particles ranging from quarks to atoms, and being able to scale all of those orders of magnitudes is pretty impressive in the world of quantum mechanics.  The other cool thing is that the effect repeats itself.  Efimov predicted that if you find a stable trimer, you would find another one by scaling the energy up or down a factor of 22.7… and you could do this forever.  There is no other word to describe this but awesome.

Unfortunately for the theory, experimentalists have had a hard time proving it.  Early work by nuclear physicists failed to find the trimers because the systems had too much kinetic energy from heat.  Using laser cooling, physicists have been able to remove so much energy from the atoms that quantum effects would start to show.   Dr. Hulet’s group used another quantum effect, called Feshbach resonance, to manipulate how cooled lithium atoms would interact with each.  They found the predicted scaling of the trimers and also found a predicted tetramer state of four particles close to each trimer.  In a fitting end to this story, Hulet announced the results at a meeting in Rome that Efimov was also attending.  Efimov, excited for proof of his theory after so long, gave Dr. Hulet a high five after the meeting ended.

Is the Earth Hydroelectric?

Prepare to have your textbooks rewritten Earth science majors.  Or at least that might happen if new research into Earth’s magnetic field holds true.  Gregory Ryskin from Northwestern has developed a new theory of what produces the field.  Current theories, called dynamo theories, say that the field is a result of convection currents and rotation in the outer core.  Since the outer core is a layer of molten, electrically conductive iron this creates a magnetic field, though the actual details are a bit more complicated than that.  And of course, the operative term describing the current view is “theories”.  Geophysicists haven’t worked out the final details, and the article mentions that computer models tend to produce different results.

Ryskin takes a radically different approach.  He was looking to explain the constant changes in magnetic field strength in different regions.  Currently, these are blamed on turbulence in the core.  Ryskin based his theory on something else that is constantly changing:  ocean currents.  Saltwater is electrically conductive, so it could work similar to the molten iron of the core.  One piece of evidence in support of the new theory is that changes in the strength of ocean currents have been linked to changes in magnetic fields.  The theory also has some interesting consequences. Changes in ocean currents might be linked to geomagnetic field reversals.  The movement of tectonic plates and landmasses alters the routes currents follow, and therefore would affect the Earth’s magnetic field.  Climate changes that affect ocean currents would also have an effect on the magnetic field.

Ryskin himself is an interesting researcher as you can see on his faculty page.  He’s a chemical and biological engineering professor at Northwestern.  But a good deal of his work is on physics, and now, geology (all the recent articles listed on his page went to a physics journal, with the exception of one geology paper).  Score one for multidisciplinarity?  I think so.  The traditional geologists don’t seem terribly excited by the new research.  I wonder if it’s some slight bias against an outsider coming in and trying to rework a central tenet of their field.  More likely, though, this is just another case of slow acceptance of new theories in science. The dynamo theory does a lot, so there’s no need to drop it at the first sign of something else.  More evidence is needed.

Also, I seem to have lots of questions about how we could get this evidence.  I feel that it would be relatively easy to test Ryskin’s theory directly.  Couldn’t we just get a lab to make a model of Earth and the oceans, rotate it, and measure the magnetic fields?  Or just pore over several years of data on magnetic fields and ocean currents from NASA and analyze it for correlations?  I still like the dynamo theory after having read lots of books on the planets, but Ryskin’s theory makes me wonder about the very watery nature of Earth.  The oceans are electrically conductive and the currents move relative to Earth’s rotation.  Perhaps they could affect the strength of magnetic field, even if they aren’t the cause?