Tag Archives: metaphors

Fuel cells and iron veins and Ballard Power Systems

The iron ‘veins’ are an idea from the researchers at the US National Institute of Standards and Technology (NIST) that might make fuel cells a standard piece of equipment in a car. From the August 31, 2011 news item on Nanowerk,

With a nod to biology, scientists at the National Institute of Standards and Technology (NIST) have a new approach to the problem of safely storing hydrogen in future fuel-cell-powered cars. Their idea: molecular scale “veins” of iron permeating grains of magnesium like a network of capillaries. The iron veins may transform magnesium from a promising candidate for hydrogen storage into a real-world winner (“Thermodynamics, kinetics and microstructural evolution during hydrogenation of iron-doped magnesium thin films”).

Hydrogen has been touted as a clean and efficient alternative to gasoline, but it has one big drawback: the lack of a safe, fast way to store it onboard a vehicle. According to NIST materials scientist Leo Bendersky, iron-veined magnesium could overcome this hurdle. The combination of lightweight magnesium laced with iron could rapidly absorb—and just as importantly, rapidly release—sufficient quantities of hydrogen so that grains made from the two metals could form the fuel tank for hydrogen-powered vehicles.

There are more technical details in the Nanowerk news item.

Since Ballard Power Systems, known for its fuel cell powered buses, is located in the Vancouver area (the region where I live) I was curious as the why this NIST advance is considered so wonderful. After all, fuel cells are already being used commercially. From the Ballard website page on buses,

Ballard designs and manufactures fully-integrated FC velocity®-HD6 fuel cell modules delivering 75 kW or 150 kW of power for use in the bus market. Ballard’s leading-edge fuel cell technology combined with our customer’s advanced hybrid bus system designs have demonstrated improved vehicle performance, durability and lower cost. All of which has created a path to commercialization for the fuel cell hybrid bus.

Zero-emission fuel cell-powered buses deliver economic, operational as well as environmental benefits, when compared to traditional diesel or diesel hybrid systems. Economic benefits are a direct result of increased fuel cell efficiency and reliability. And fuel cell buses emit only water vapour, eliminating air pollutants such as nitrogen oxides, sulphur oxides and particulate matter. Fuel cell buses can also significantly reduce greenhouse gas emissions on a “well-to-wheel” basis, when compared to conventional technologies.

I note Ballard has a hybrid system so perhaps the NIST researchers are working on a 100% fuel cell system? I did check one more thing while I was on the Ballard website, the technical specifications for the fuel cells used to power the buses. The weight for the smaller 75w fuel cell is 350 kg or 772 lbs. and its dimensions are 1530 x 871 x 495 mm or 50 x 34 x 12 in. With that weight and those dimensions, I imagine that’s why we haven’t been hearing about hybrid fuel cell cars. I now better understand why the NIST researchers are excited.

Graphene, IBM’s first graphene-based integrated circuit, and the European Union’s pathfinder programme in information technologies

A flat layer of carbon atoms packed into a two-dimensional honeycomb arrangement, graphene is being touted as a miracle (it seems)  material which will enable new kinds of electronic products. Recently, there have been a number of news items and articles featuring graphene research.

Here’s my roundup of the latest and greatest graphene news. I’m starting with an application that is the closest to commercialization: IBM recently announced the creation of the first graphene-based integrated circuit. From the Bob Yirka article dated June 10, 2011 on physorg.com,

Taking a giant step forward in the creation and production of graphene based integrated circuits, IBM has announced in Science, the fabrication of a graphene based integrated circuit [IC] on a single chip. The demonstration chip, known as a radio frequency “mixer” is capable of producing frequencies up to 10 GHz, and demonstrates that it is possible to overcome the adhesion problems that have stymied researchers efforts in creating graphene based IC’s that can be used in analog applications such as cell phones or more likely military communications.

The graphene circuits were started by growing a two or three layer graphene film on a silicon surface which was then heated to 1400°C. The graphene IC was then fabricated by employing top gated, dual fingered graphene FET’s (field-effect transistors) which were then integrated with inductors. The active channels were made by spin-coating the wafer with a thin polymer and then applying a layer of hydrogen silsequioxane. The channels were then carved by e-beam lithography. Next, the excess graphene was removed with an oxygen plasma laser, and then the whole works was cleaned with acetone. The result is an integrated circuit that is less than 1mm2 in total size.

Meanwhile, there’s a graphene research project in contention for a major research prize in Europe. Worth 1B Euros, the European Union’s 2011 pathfinder programme (Future and Emerging Technologies [Fet11]) in information technology) will select two from six pilot actions currently under way to be awarded a Flagship Initiative prize.  From the Fet11 flagships project page,

FET Flagships are large-scale, science-driven and mission oriented initiatives that aim to achieve a visionary technological goal. The scale of ambition is over 10 years of coordinated effort, and a budget of up to one billion Euro for each Flagship. They initiatives are coordinated between national and EU programmes and present global dimensions to foster European leadership and excellence in frontier research.

To prepare the launch of the FET Flagships, 6 Pilot Actions are funded for a 12-month period starting in May 2011. In the second half of 2012 two of the Pilots will be selected and launched as full FET Flagship Initiatives in 2013.

Here’s the description of the Graphene Science and technology for ICT and beyond pilot action,

Graphene, a new substance from the world of atomic and molecular scale manipulation of matter, could be the wonder material of the 21st century. Discovering just how important this material will be for Information and Communication Technologies is the long term focus of the Flagship Initiative, simply called, GRAPHENE. This aims to explore revolutionary potentials, in terms of both conventional as well as radically new fields of Information and Communication Technologies applications.

Bringing together multiple disciplines and addressing research across a whole range of issues, from fundamental understandings of material properties to Graphene production, the Flagship will provide the platform for establishing European scientific and technological leadership in the application of Graphene to Information and Communication Technologies. The proposed research includes coverage of electronics, spintronics, photonics, plasmonics and mechanics, all based on Graphene.

[Project Team:]

Andrea Ferrari, Cambridge University, UK
Jari Kinaret, Chalmers University, Sweden
Vladimir Falko, Lancaster University, UK
Jani Kivioja, NOKIA, Finland [emphases mine]

Not so coincidentally (given one member of the team is associated with Nokia and another is associated with Cambridge University), the Nokia Research Centre jointly with Cambridge University issued a May 4, 2011 news release (I highlighted it in my May 6, 2011 posting [scroll down past the theatre project information]) about the Morph concept (a rigid, flexible, and stretchable phone/blood pressure cuff/calculator/and  other electronic devices in one product) which they have been publicizing for years now. The news release concerned itself with how graphene would enable the researchers to take the Morph from idea to actuality. The webpage for the Graphene Pilot Action is here.

There’s something breathtaking when there is no guarantee of success about the willingness to invest up to 1B Euros in a project that spans 10 years. We’ll have to wait until 2013 before learning whether the graphene project will be one of the two selected as Flagship Initiatives.

I must say the timing for the 2010 Nobel Prize for Physics which went to two scientists (Andre Geim and Konstantin Novoselov) for their groundbreaking work with graphene sems interesting (featured in my Oct. 7, 2010 posting) in light of this graphene activity.

The rest of these graphene items are about research that could lay the groundwork for future commercialization.

Friday, June 13, 2011 there was a news item about foaming graphene on Nanowerk (from the news item),

Hui-Ming Cheng and co-workers from the Chinese Academy of Sciences’ Institute of Metal Research at Shenyang have now devised a chemical vapor deposition (CVD) method for turning graphene sheets into porous three-dimensional ‘foams’ with extremely high conductivity (“Three-dimensional flexible and conductive interconnected graphene networks grown by chemical vapour deposition” [published in Nature Materials 10, 424–428 (2011) doi:10.1038/nmat3001 Published online 10 April 2011]). By permeating this foam with a siloxane-based polymer, the researchers have produced a composite that can be twisted, stretched and bent without harming its electrical or mechanical properties.

Here’s an image from the Nature Publishing Group (NPG) of both the vapour and the bendable, twistable, stretchable composite (downloaded from the news item on Nanowerk where you can find a larger version of the image),

A scanning electron microscopy image of the net-like structure of graphene foam (left), and a photograph of a highly conductive elastic conductor produced from the foam. (© 2011 NPG)

The ‘elastic’ conductor (image to the right) reminds me of the ‘paper’ phone which I wrote about May 8, 2011 and May 12, 2011. (It’s a project where teams from Queen’s University [in Ontario] and Arizona State University are working to create flexible screens that give you telephony, music playing and other capabilities  much like the Morph concept.)

Researchers in Singapore have developed a graphene quantum dot using a C60 (a buckminster fullerene). From the June 13, 2011 news item (Graphene: from spheres to perfect dots) on Nanowerk,

An electron trapped in a space of just a few nanometers across behaves very differently to one that is free. Structures that confine electrons in all three dimensions can produce some useful optical and electronic effects. Known as quantum dots, such structures are being widely investigated for use in new types of optical and electronics technologies, but because they are so small it is difficult to fabricate quantum dots reproducibly in terms of shape and size. Researchers from the National University of Singapore (NUS) and A*STAR have now developed a technique that enables graphene quantum dots of a known size to be created repeatedly and quickly (“Transforming C60 molecules into graphene quantum dots” [published in Nature Nanotechnology 6, 247–252 (2011) doi:10.1038/nnano.2011.30 Published online 20 March 2011]).

This final bit is about a nano PacMan that allows for more precise patterning from a June 13, 2011 article written by Michael Berger,

A widely discussed method for the patterning of graphene is the channelling of graphite by metal nanoparticles in oxidizing or reducing environments (see for instance: “Nanotechnology PacMan cuts straight graphene edges”).

“All previous studies of channelling behavior have been limited by the need to perform the experiment ex situ, i.e. comparing single ‘before’ and ‘after’ images,” Peter Bøggild, an associate professor at DTU [Danish Technical University] Nanotech, explains to Nanowerk. “In these and other ex situ experiments the dynamic behavior must be inferred from the length of channels and heating time after completion of the experiment, with the rate of formation of the channel assumed to be consistent over the course of the experiment.”

In new work, reported in the June 9, 2011 advance online edition of Nano Letters (“Discrete dynamics of nanoparticle channelling in suspended graphene” [published in Nano Letters, Article ASAP, DOI: 10.1021/nl200928k, Publication Date (Web): June 9, 2011]), Bøggild and his team report the nanoscale observation of this channelling process by silver nanoparticles in an oxygen atmosphere in-situ on suspended mono- and bilayer graphene in an environmental transmission electron microscope, enabling direct concurrent observation of the process, impossible in ex-situ experiments.

Personally, I love the youtube video I’ve included here largely because it features blobs (as many of these videos do) where they’ve added music and titles (many of these videos do not) so you can better appreciate the excitement,

From the article by Michael Berger,

As a result of watching this process occur live in a transmission electron microscope, the researchers say they have seen many details that were hidden before, and video really brings the “nano pacman” behavior to life …

There’s a reason why they’re so interested in cutting graphene,

“With a deeper understanding of the fine details we hope to one day use this nanoscale channelling behavior to directly cut desired patterns out of suspended graphene sheets, with a resolution and accuracy that isn’t achievable with any other technique,” says Bøggild. “A critical advantage here is that the graphene crystal structure guides the patterning, and in our case all of the cut edges of the graphene are ‘zigzag’ edges.”

So there you have it. IBM creates the first integrated graphene-based circuit, there’s the prospect of a huge cash prize for a 10-year project on graphene so they could produce the long awaited Morph concept and other graphene-based electronics products while a number of research teams around the world continue teasing out its secrets with graphene ‘foam’ projects, graphene quantum dots, and nano PacMen who cut graphene’s zigzag edges with precision.

ETA June 16, 2011: For those interested in the business end of things, i.e. market value of graphene-based products, Cameron Chai features a report, Graphene: Technologies, Applications, and Markets, in his June 16, 2011 news item on Azonano.

Rainbows, what are we going to do with them?

The title is attention-getting initially then quickly leads to confusion for anyone not familiar with plasmonics, “Trapping a rainbow: Researchers slow broadband light waves with plasmonic structures.” I have to confess to being more interested in the use of the metaphor than I am in the science. However in deference to any readers who are more taken by the science, here’s more from the March 14, 2011 news item on Nanowerk,

A team of electrical engineers and chemists at Lehigh University have experimentally verified the “rainbow” trapping effect, demonstrating that plasmonic structures can slow down light waves over a broad range of wavelengths.

The idea that a rainbow of broadband light could be slowed down or stopped using plasmonic structures has only recently been predicted in theoretical studies of metamaterials. The Lehigh experiment employed focused ion beams to mill a series of increasingly deeper, nanosized grooves into a thin sheet of silver. By focusing light along this plasmonic structure, this series of grooves or nano-gratings slowed each wavelength of optical light, essentially capturing each individual color of the visible spectrum at different points along the grating. The findings hold promise for improved data storage, optical data processing, solar cells, bio sensors and other technologies.

While the notion of slowing light or trapping a rainbow sounds like ad speak, finding practical ways to control photons—the particles that makes up light— could significantly improve the capacity of data storage systems and speed the processing of optical data.

The research required the ability to engineer a metallic surface to produce nanoscale periodic gratings with varying groove depths. This alters the optical properties of the nanopatterned metallic surface, called Surface Dispersion Engineering. The broadband surface light waves are then trapped along this plasmonic metallic surface with each wavelength trapped at a different groove depth, resulting in a trapped rainbow of light.

You can get still more scientific detail in the item but I found a later posting, April 12, 2011 news item, also on Nanowerk, where the researcher Qiaoquiang Gan (pronounced “Chow-Chung” and “Gone”) gave this description for his work,

An electrical engineer at the University at Buffalo, who previously demonstrated experimentally the “rainbow trapping effect” [emphasis mine] — a phenomenon that could boost optical data storage and communications — is now working to capture all the colors of the rainbow.

In a paper published March 29 in the Proceedings of the National Academy of Sciences, Qiaoquiang Gan (pronounced “Chow-Chung” and “Gone”), PhD, an assistant professor of electrical engineering at the University at Buffalo’s School of Engineering and Applied Sciences, and his colleagues at Lehigh University, where he was a graduate student, described how they slowed broadband light waves using a type of material called nanoplasmonic structures.

Gan explains that the ultimate goal is to achieve a breakthrough in optical communications called multiplexed, multiwavelength communications, where optical data can potentially be tamed at different wavelengths, thus greatly increasing processing and transmission capacity.

“Light is usually very fast, but the structures I created can slow broadband light significantly,” says Gan. “It’s as though I can hold [emphasis mine] the light in my hand.”

I like the notion of ‘holding’ a rainbow better than ‘trapping’ one. (ETA April 18, 2011: The original sentence, now placed at the end of this posting, has been replaced with this: There’s a big difference between the two verbs, trapping and holding and each implies a difference relationship to the object. Which would you prefer, to be trapped or to be held? What does it mean to the one who does the trapping or the holding? Two difference relationships to the object and to the role of a scientist are implied.

It’s believed that the metaphors we use when describing science have a powerful impact on how science is viewed and practiced. One example I have at hand is a study by Kevin Dunbar mentioned in my Jan. 4, 2010 posting (scroll down) where he illustrates how scientists use metaphors to achieve scientific breakthroughs. Logically, if metaphors help us achieve breakthroughs, then they are quite capable of constraining us as well.

Meanwhile, this gives me an excuse to include this video of a Hawaiian singer, Israel Kamakawiwo’ole and his extraordinary version of Somewhere over the Rainbow. Happy Weekend!

The original (April 15, 2011) sentence:
It’s more gentle and implies a more humble attitude and I suspect it would ultimately prove more fruitful.

Thoughts on part 4 of (PBS) Nova’s Making Stuff series

Last night (Feb.9.11) PBS aired the final part of the Making Stuff  series as part of its Nova tv programming. It was titled Making Stuff Smarter and did not feature a single bot of any kind or any nanoscale computers or labs on chips thereby frustrating (not in a bad way) some of my expectations but I should have become accustomed to that by now.

There was a focus on something called biomimicry, a term I did not hear used while I was watching (confession: I didn’t watch every single minute of the show), where researchers try to make materials that mimic a process or ability observed in nature. They used sharkskin as an example for making a ‘smarter’ material. Scientists have observed that nanoscale structures on a shark’s skin have antibacterial properties. This is especially important when we have a growing problem with bacteria that are antibiotic resistant. David Pogue’s (the program host) interviewed scientists at Sharklet and highlighted their work producing a plastic with nanostructures similar to those found on sharkskin for use in hospitals, restaurants, etc.  I found this on the Sharklet website (from a rotating graphic on the home page),

The World Health Organization calls antibiotic resistance a leading threat to human health.

Sharkjet provides a non-toxic approach to bacterial control and doesn’t create resistance.

The reason that the material does not create resistance is that it doesn’t kill the bacteria (antibiotics kill most bacteria but cannot kill all of them with the consequence that only the resistant survive and reproduce). Excerpted from Sharklet’s technology page,

While the Sharklet pattern holds great promise to improve the way humans co-exist with microorganisms, the pattern was developed far outside of a laboratory. In fact, Sharklet was discovered via a seemingly unrelated problem: how to keep algae from coating the hulls of submarines and ships. In 2002, Dr. Anthony Brennan, a materials science and engineering professor at the University of Florida, was visiting the U.S. naval base at Pearl Harbor in Oahu as part of Navy-sponsored research. The U.S. Office of Naval Research solicited Dr. Brennan to find new antifouling strategies to reduce use of toxic antifouling paints and trim costs associated with dry dock and drag.

Dr. Brennan was convinced that using an engineered topography could be a key to new antifouling technologies. Clarity struck as he and several colleagues watched an algae-coated nuclear submarine return to port. Dr. Brennan remarked that the submarine looked like a whale lumbering into the harbor. In turn, he asked which slow moving marine animals don’t foul. The only one? The shark.

Dr. Brennan was inspired to take an actual impression of shark skin, or more specifically, its dermal denticles. Examining the impression with scanning electron microscopy, Dr. Brennan confirmed his theory. Shark skin denticles are arranged in a distinct diamond pattern with tiny riblets. Dr. Brennan measured the ribs’ width-to-height ratios which corresponded to his mathematical model for roughness – one that would discourage microorganisms from settling. The first test of Sharklet yielded impressive results. Sharklet reduced green algae settlement by 85 percent compared to smooth surfaces.

There’s more to the story so I encourage you to take a look at the page. What I find compelling about biomimicry is that we are learning from nature and mimicking it rather than try to control or destroy what we view as dangerous to us or, in some cases, not valuable. Interestingly, this program featured the military quite prominently in other segments while, as far as I’m aware, failing to mention biomimcry  which suggests (I’m putting on my semiotic hat) that our ideas about controlling nature and using warlike metaphors to describe scientific and medical efforts are still dominant socially and being reproduced.

I enjoyed (with qualifications regarding some of the subtext) the program series (all three of the shows I managed to watch) but, as I’ve noted previously, I’m not the target market so some of it was a bit too fluffy for me.

I found this fourth installment the most interesting and I was delighted to see that they featured climbing robots (based on geckos and mentioned in my Aug. 2, 2010 posting) and invisibility (mentioned most recently in my Jan. 26, 2011 posting although that features a different approach than the one mentioned in the program) along with a few items that were new to me.

Coincidentally the National Film Board of Canada is featuring a film short titled, Magic Molecule in its Feb. 9, 2011 newsletter. Produced in 1964, it introduces us to the fabulous world of plastics. In some ways, it’s very similar to the Making Stuff series. The tone is upbeat and very much pro plastics and its wonders.

More bimetallic nanoparticles

Two days ago, I noted that I’d never encountered bimetallic nanoparticles before reading about the ‘Christmas decorations’ created by a Mexico/US research team (my Dec. 6, 2010 posting). Live and learn. Here’s another bimetallic (gold and silver this time too) news item on Nanowerk,

Shrink Nanotechnologies, Inc. (“Shrink”), an innovative nanotechnology company developing products and licensing opportunities in the solar energy industry, medical diagnostics and sensors and biotechnology research and development tools businesses, announced today that Shrink’s MetalFluor™ technology was studied, reported on and made the front cover of the November issue of Applied Physics Letters (“Bimetallic nanopetals for thousand-fold fluorescence enhancements”). [the article is behind a paywall]

I was most interested to note that at least one of the authors is a researcher associated with the company that issued the news release trumpeting the article in Applied Physics Letters. From the news item on Nanowerk,

The Company’s technology and the work being performed by Dr. Michelle Khine, our scientific founder, continues to gain high praise from leading academic journals. [emphases mine] The studies relate to potential commercial applications of this technology. Of note, the article states, “Because we have a range of nanostructure and nanogap sizes, we can ensure that we can achieve huge fluorescent enhancements on our substrate. These advantages show great potential for low-cost biomedical sensing at single molecular levels at physiological concentrations.” The Company believes that this article is further evidence that certain medical diagnostics tests, a multi-billion dollar annual industry in the United States alone, can provide physicians, patients and other medical professionals with better results using lower quantities of specimens using MetalFluor™ technologies.

Here’s more about possible uses for the technology cited in the article in Applied Physics Letters (citation: Bimetallic nanopetals for thousand-fold fluorescence enhancements by Chi-Cheng Fu1, Giulia Ossato, Maureen Long, Michelle A. Digman, Ajay Gopinathan, Luke P. Lee, Enrico Gratton, and Michelle Khine in vol. 97, issue no. 20, Nov. 15, 2010),

Our method can be easily integrated with microfluidic devices to combine with high throughput lab-on-chip techniques. Importantly, because of–not in spite of–the “variability” in our substrate, we do not need to choose an esoteric dye such that it would match our plasmon resonance. Because we have a range of nanostructure and nanogap sizes, we can ensure that we can achieve huge fluorescence enhancements on our substrate. These advantages show great potential for low-cost biomedical sensing at single molecular levels at physiological concentrations.

The company Khine founded is very interesting from an organizational perspective (the news item on Nanowerk),

Shrink is a first of its kind FIGA™ organization. FIGA companies bring together diverse contributions from leaders in the worlds of finance, industry, government and academia. [emphases mine] Shrink’s solutions, including its diverse polymer substrates, nano-devices and biotech research tools, among others, are designed to be ultra-functional and mechanically superior in the solar energy, environmental detection, stem cell and biotechnology markets. The Company’s products are based on a pre-stressed plastic called NanoShrink™, and on a patent-pending manufacturing process called the ShrinkChip Manufacturing Solution™. Shrink’s unique materials and manufacturing solution represents a new paradigm in the rapid design, low-cost fabrication and manufacture of nano-scale devices for numerous significant markets.

I can’t make much of this academic/business hybrid but I am intrigued and will watch its progress with some interest. You can visit the Shrink Nanotechnologies website here.

Stickybots at Stanford University

I’ve been intrigued by ‘gecko technology’ or ‘spiderman technology’ since I first started investigating nanotechnology about four years ago.  This is the first time I’ve seen theory put into practice. From the news item on Nanowerk,

Mark Cutkosky, the lead designer of the Stickybot, a professor of mechanical engineering and co-director of the Center for Design Research [Stanford University], has been collaborating with scientists around the nation for the last five years to build climbing robots.

After designing a robot that could conquer rough vertical surfaces such as brick walls and concrete, Cutkosky moved on to smooth surfaces such as glass and metal. He turned to the gecko for ideas.

“Unless you use suction cups, which are kind of slow and inefficient, the other solution out there is to use dry adhesion, which is the technique the gecko uses,” Cutkosky said.

Here’s a video of Stanford’s Stickybot in  action (from the Stanford University News website),

As Cutkosky goes on to explain in the news item,

The interaction between the molecules of gecko toe hair and the wall is a molecular attraction called van der Waals force. A gecko can hang and support its whole weight on one toe by placing it on the glass and then pulling it back. It only sticks when you pull in one direction – their toes are a kind of one-way adhesive, Cutkosky said.

“Other adhesives are sort of like walking around with chewing gum on your feet: You have to press it into the surface and then you have to work to pull it off. But with directional adhesion, it’s almost like you can sort of hook and unhook yourself from the surface,” Cutkosky said.

After the breakthrough insight that direction matters, Cutkosky and his team began asking how to build artificial materials for robots that create the same effect. They came up with a rubber-like material with tiny polymer hairs made from a micro-scale mold.

The designers attach a layer of adhesive cut to the shape of Stickybot’s four feet, which are about the size of a child’s hand. As it steadily moves up the wall, the robot peels and sticks its feet to the surface with ease, resembling a mechanical lizard.

The newest versions of the adhesive, developed in 2009, have a two-layer system, similar to the gecko’s lamellae and setae. The “hairs” are even smaller than the ones on the first version – about 20 micrometers wide, which is five times thinner than a human hair. These versions support higher loads and allow Stickybot to climb surfaces such as wood paneling, painted metal and glass.

The material is strong and reusable, and leaves behind no residue or damage. Robots that scale vertical walls could be useful for accessing dangerous or hard to reach places.

The research team’s paper, Effect of fibril shape on adhesive properties, was published online Aug. 2, 2010 in Applied Physics Letter.

Folding, origami, and shapeshifting and an article with over 50,000 authors

I’m on a metaphor kick these days so here goes, origami (Japanese paper folding), and shapeshifting are metaphors used to describe a certain biological process that nanoscientists from fields not necessarily associated with biology find fascinating, protein folding.

Origami

Take for example a research team at the California Institute of Technology (Caltech) working to exploit the electronic properties of carbon nanotubes (mentioned in a Nov. 9, 2010 news item on Nanowerk). One of the big issues is that since all of the tubes in a sample are made of carbon getting one tube to react on its own without activating the others is quite challenging when you’re trying to create nanoelectronic circuits. The research team decided to use a technique developed in a bioengineering lab (from the news item),

DNA origami is a type of self-assembled structure made from DNA that can be programmed to form nearly limitless shapes and patterns (such as smiley faces or maps of the Western Hemisphere or even electrical diagrams). Exploiting the sequence-recognition properties of DNA base paring, DNA origami are created from a long single strand of viral DNA and a mixture of different short synthetic DNA strands that bind to and “staple” the viral DNA into the desired shape, typically about 100 nanometers (nm) on a side.

Single-wall carbon nanotubes are molecular tubes composed of rolled-up hexagonal mesh of carbon atoms. With diameters measuring less than 2 nm and yet with lengths of many microns, they have a reputation as some of the strongest, most heat-conductive, and most electronically interesting materials that are known. For years, researchers have been trying to harness their unique properties in nanoscale devices, but precisely arranging them into desirable geometric patterns has been a major stumbling block.

… To integrate the carbon nanotubes into this system, the scientists colored some of those pixels anti-red, and others anti-blue, effectively marking the positions where they wanted the color-matched nanotubes to stick. They then designed the origami so that the red-labeled nanotubes would cross perpendicular to the blue nanotubes, making what is known as a field-effect transistor (FET), one of the most basic devices for building semiconductor circuits.

Although their process is conceptually simple, the researchers had to work out many kinks, such as separating the bundles of carbon nanotubes into individual molecules and attaching the single-stranded DNA; finding the right protection for these DNA strands so they remained able to recognize their partners on the origami; and finding the right chemical conditions for self-assembly.

After about a year, the team had successfully placed crossed nanotubes on the origami; they were able to see the crossing via atomic force microscopy. These systems were removed from solution and placed on a surface, after which leads were attached to measure the device’s electrical properties. When the team’s simple device was wired up to electrodes, it indeed behaved like a field-effect transistor

Shapeshifting

For another more recent example (from an August 5, 2010 article on physorg.com by Larry Hardesty,  Shape-shifting robots),

By combining origami and electrical engineering, researchers at MIT and Harvard are working to develop the ultimate reconfigurable robot — one that can turn into absolutely anything. The researchers have developed algorithms that, given a three-dimensional shape, can determine how to reproduce it by folding a sheet of semi-rigid material with a distinctive pattern of flexible creases. To test out their theories, they built a prototype that can automatically assume the shape of either an origami boat or a paper airplane when it receives different electrical signals. The researchers reported their results in the July 13 issue of the Proceedings of the National Academy of Sciences.

As director of the Distributed Robotics Laboratory at the Computer Science and Artificial Intelligence Laboratory (CSAIL), Professor Daniela Rus researches systems of robots that can work together to tackle complicated tasks. One of the big research areas in distributed robotics is what’s called “programmable matter,” the idea that small, uniform robots could snap together like intelligent Legos to create larger, more versatile robots.

Here’s a video from this site at MIT (Massachusetts Institute of Technology) describing the process,

Folding and over 50, 000 authors

With all this I’ve been leading up to a fascinating project, a game called Foldit, that a team from the University of Washington has published results from in the journal Nature (Predicting protein structures with a multiplayer online game), Aug. 5, 2010.

With over 50,000 authors, this study is a really good example of citizen science (discussed in my May 14, 2010 posting and elsewhere here) and how to use games to solve science problems while exploiting a fascination with folding and origami. From the Aug. 5, 2010 news item on Nanowerk,

The game, Foldit, turns one of the hardest problems in molecular biology into a game a bit reminiscent of Tetris. Thousands of people have now played a game that asks them to fold a protein rather than stack colored blocks or rescue a princess.

Scientists know the pieces that make up a protein but cannot predict how those parts fit together into a 3-D structure. And since proteins act like locks and keys, the structure is crucial.

At any moment, thousands of computers are working away at calculating how physical forces would cause a protein to fold. But no computer in the world is big enough, and computers may not take the smartest approach. So the UW team tried to make it into a game that people could play and compete. Foldit turns protein-folding into a game and awards points based on the internal energy of the 3-D protein structure, dictated by the laws of physics.

Tens of thousands of players have taken the challenge. The author list for the paper includes an acknowledgment of more than 57,000 Foldit players, which may be unprecedented on a scientific publication.

“It’s a new kind of collective intelligence, as opposed to individual intelligence, that we want to study,”Popoviç [principal investigator Zoran Popoviç, a UW associate professor of computer science and engineering] said. “We’re opening eyes in terms of how people think about human intelligence and group intelligence, and what the possibilities are when you get huge numbers of people together to solve a very hard problem.”

There’s a more at Nanowerk including a video about the gamers and the scientists. I think most of us take folding for granted and yet it stimulates all kinds of research and ideas.

Quantum kind of day: metaphors, language and nanotechnology

I had a bonanza day on the Nanowerk website yesterday as I picked up three items, all of which featured the word ‘quantum’ in the title and some kind of word play or metaphor.

From the news item, Quantum dots go with the flow,

Quantum dots may be small. But they usually don’t let anyone push them around. Now, however, JQI [Joint Quantum Institute] Fellow Edo Waks and colleagues have devised a self-adjusting remote-control system that can place a dot 6 nanometers long to within 45 nm of any desired location. That’s the equivalent of picking up golf balls around a living room and putting them on a coffee table – automatically, from 100 miles away.

There’s a lot of detail in this item which gives you more insight (although the golf ball analogy does that job very well) into just how difficult it is to move a quantum dot and some of the problems that had to be solved.

Next, A quantum leap for cryptography,

To create random number lists for encryption purposes, cryptographers usually use mathematical algorithms called ‘pseudo random number generators’. But these are never entirely ‘random’ as the creators cannot be certain that any sequence of numbers isn’t predictable in some way.

Now a team of experimental physicists has made a breakthrough in random number generation by applying the principles of quantum mechanics to produce a string of numbers that is truly random.

‘Classical physics simply does not permit genuine randomness in the strict sense,’ explained research team leader Chris Monroe from the Joint Quantum Institute (JQI) at the University of Maryland in the US. ‘That is, the outcome of any classical physical process can ultimately be determined with enough information about initial conditions. Only quantum processes can be truly random — and even then, we must trust the device is indeed quantum and has no remnant of classical physics in it.’

This is a drier piece (I suspect that’s due to the project itself) so the language or word play is in the headline. I immediately thought of a US tv series titled, Quantum Leap where, for five seasons, a scientist’s personality/intellect/spirit is leaping into people’s bodies, randomly through time. There are, according to Wikipedia, two other associations, a scientific phenomenon and a 1980s era computer. You can go here to pursue links for the other two associations. This is very clever in that you don’t need to have any associations to understand the base concept in the headline but having one or more association adds a level or more of engagement.

The final item, Scientists climb the quantum ladder,

An EU [European Union]-funded team of scientists from Cardiff University in the UK has successfully fired photons (light particles) into a small tower of semiconducting material. The work could eventually lead to the development of faster computers. …

The scientists, from the university’s School of Physics and Astronomy, said a photon collides with an electron confined in a smaller structure within the tower. Before the light particles re-emerge, they oscillate for a short time between the states of light and matter.

While I find this business of particles oscillating between two different states, light and matter, quite fascinating this particular language play is the least successful. I think most people will do what I did and miss the relationship between the ‘tower’ in the news item’s first paragraph and the ‘ladder’ in the headline. I cannot find any other attempt to play with either linguistic image elsewhere in the item.

Given that I’m  a writer I’m going to argue that analogies, metaphors, and word play are essential when trying to explain concepts to audiences that may not have your expertise and that audience can include other scientists. Here’s an earlier posting about some work by a cognitive psychologist, Kevin Dunbar, who investigates how scientists think and communicate.