Tag Archives: Shrinky Dinks

Nano crafts class: get out your ‘paper’ and scissors

It’s not all atomic force microscopy and nanotweezers as scientists keep reminding us that the techniques we learned in kindergarten can be all the high technology we need even when working at the nanoscale. From the Nov. 14, 2012 news item on ScienceDaily,

Two Northwestern University researchers have discovered a remarkably easy way to make nanofluidic devices: using paper and scissors. And they can cut a device into any shape and size they want, adding to the method’s versatility.

The Nov. 14, 2012 Northwestern University news release by Megan Fellman explains both nanofluidic devices and the new technique,

Nanofluidic devices are attractive because their thin channels can transport ions — and with them a higher than normal electric current — making the devices promising for use in batteries and new systems for water purification, harvesting energy and DNA sorting.

The “paper-and-scissors” method one day could be used to manufacture large-scale nanofluidic devices without relying on expensive lithography techniques.

The Northwestern duo found that simply stacking up sheets of the inexpensive material graphene oxide creates flexible “paper” with tens of thousands of very useful channels. A tiny gap forms naturally between neighboring sheets, and each gap is a channel through which ions can flow.

Using a pair of regular scissors, the researchers simply cut the paper into a desired shape, which, in the case of their experiments, was a rectangle.

“In a way, we were surprised that these nanochannels actually worked, because creating the device was so easy,” said Jiaxing Huang, who conducted the research with postdoctoral fellow Kalyan Raidongia. “No one had thought about the space between sheet-like materials before. Using the space as a flow channel was a wild idea. We ran our experiment at least 10 times to be sure we were right.”

The process is a little more complex than kindergarten crafts (from Fellman’s news release),

To create a working device, the researchers took a pair of scissors and cut a piece of their graphene oxide paper into a centimeter-long rectangle. They then encased the paper in a polymer, drilled holes to expose the ends of the rectangular piece and filled up the holes with an electrolyte solution (a liquid containing ions) to complete the device.

Next they put electrodes at both ends and tested the electrical conductivity of the device. Huang and Raidongia observed higher than normal current, and the device worked whether flat or bent.

The nanochannels have significantly different — and desirable — properties from their bulk channel counterparts, Huang said. The nanochannels have a concentrating effect, resulting in an electric current much higher than those in bulk solutions.

Graphene oxide is basically graphene sheets decorated with oxygen-containing groups. It is made from inexpensive graphite powders by chemical reactions known for more than a century.

Scaling up the size of the device is simple. Tens of thousands of sheets or layers create tens of thousands of nanochannels, each channel approximately one nanometer high. There is no limit to the number of layers — and thus channels — one can have in a piece of paper.

To manufacture very massive arrays of channels, one only needs to put more graphene oxide sheets in the paper or to stack up many pieces of paper. A larger device, of course, can handle larger quantities of electrolyte.

Kindergarten techniques worked well for Andre Geim and Konstantin Novoselov who received Nobel prizes for their work on graphene (from my Oct. 7,2010 posting),

The technique that Geim and Novoselov used to create the first graphene sheets both amuses and fascinates me (from the article by Kit Eaton on the Fast Company website),

The two scientists came up with the technique that first resulted in samples of graphene–peeling individual atoms-deep sheets of the material from a bigger block of pure graphite. The science here seems almost foolishly simple, but it took a lot of lateral thinking to dream up, and then some serious science to investigate: Geim and Novoselo literally “ripped” single sheets off the graphite by using regular adhesive tape.

Then, there’s the ‘Shrinky Dinks’ nanopatterning technique (from my Aug. 16,2010 posting),

Scientists at a Northwestern University laboratory have taken to using a children’s arts and crafts product, Shrinky Dinks, for a new way to create large area nanoscale patterns on the cheap.

It’s good to be reminded that science at its heart is not about expensive equipment and complicated techniques but a means of exploring the world around us with the means at hand.

Graphene, the Nobel Prize, and levitating frogs

As you may have heard, two  scientists (Andre Geim and Konstantin Novoselov) who performed groundbreaking research on graphene [Nov. 29, 2010: I corrected this entry Nov. 26, 2010 which originally stated that these researchers discovered graphene] have been awarded the 2010 Nobel Prize for Physics. In honour of their award, the journal, Nature Materials, is giving free access to  a 2007 article authored by the scientists. From the news item on Nanowerk,

The 2007 landmark article in Nature Materials “The rise of graphene” by the just announced winners of the 2010 Nobel prize in physics, Andre Geim and Kosta Novoselov, has now been made available as a free access article.

Abstract:

Graphene is a rapidly rising star on the horizon of materials science and condensed-matter physics. This strictly two-dimensional material exhibits exceptionally high crystal and electronic quality, and, despite its short history, has already revealed a cornucopia of new physics and potential applications, which are briefly discussed here.

Here’s a description of the scientists and their work from the BBC News article by Paul Rincon,

Prof Geim, 51, is a Dutch national while Dr Novoselov, 36, holds British and Russian citizenship. Both are natives of Russia and started their careers in physics there.

The Nobels are valued at 10m Swedish kronor (£900,000; 1m euros; $1.5m).

They first worked together in the Netherlands before moving to the UK. They were based at the University of Manchester when they published their groundbreaking research paper on graphene in October 2004.

Dr Novoselov is among the youngest winners of a prize that normally goes to scientists with decades of experience.

Graphene is a form of carbon. It is a flat layer of carbon atoms tightly packed into a two-dimensional honeycomb arrangement.

Because it is so thin, it is also practically transparent. As a conductor of electricity it performs as well as copper, and as a conductor of heat it outperforms all other known materials.

The unusual electronic, mechanical and chemical properties of graphene at the molecular scale promise ultra-fast transistors for electronics.

Some scientists have predicted that graphene could one day replace silicon – which is the current material of choice for transistors.

It could also yield incredibly strong, flexible and stable materials and find applications in transparent touch screens or solar cells.

Geim and Novoselov first isolated fine sheets of graphene from the graphite which is widely used in pencils.

A layer of graphite 1mm thick actually consists of three million layers of graphene stacked on top of one another.

The technique that Geim and Novoselov used to create the first graphene sheets both amuses and fascinates me (from the article by Kit Eaton on the Fast Company website),

The two scientists came up with the technique that first resulted in samples of graphene–peeling individual atoms-deep sheets of the material from a bigger block of pure graphite. The science here seems almost foolishly simple, but it took a lot of lateral thinking to dream up, and then some serious science to investigate: Geim and Novoselo literally “ripped” single sheets off the graphite by using regular adhesive tape. Once they’d confirmed they had grabbed micro-flakes of the material, Geim and Novoselo were responsible for some of the very early experiments into the material’s properties. Novel stuff indeed, but perhaps not so unexpected from a scientist (Geim) who the Nobel Committe notes once managed to make a frog levitate in a magnetic field.

I’ll get to the levitating frog in a minute but first the bit about using regular adhesive tape to peel off single sheets only atoms thick of graphite from a larger block of the stuff reminds me of how scientists at Northwestern University are using shrinky dinks (a child’s craft material) to create large scale nanopatterns cheaply (my Aug. 16, 2010 posting).

It’s reassuring to me that despite all of the high tech equipment that costs the earth, scientists still use fairly mundane, inexpensive objects to do some incredibly sophisticated work. The other thing I find reassuring is that Novoselov probably was not voted ‘most likely to be awarded a Nobel Prize’. Interestingly, Novoselov’s partner, Geim, was not welcomed into a physics career with open arms. From the news item on physoorg.com,

Konstantin Novoselov, the Russian-born physicist who shared this year’s Nobel prize, struggled with physics as a student and was awarded a handful of B grades, his university said Wednesday.

The Moscow Physics and Technology University (MFTI) posted report cards on its website for Novoselov, who at 36 won the Nobel prize for physics with his research partner Andre Geim.

The reports reveal that he gained a handful of B grades in his term reports for theoretical and applied physics from 1991 to 1994.

He was also not strong on physical education — a compulsory subject at Russian universities — gaining B grades. And while he now lives in Britain, he once gained a C grade for English.

The university also revealed documents on Nobel prize winner Geim, who studied at the same university from 1976 to 1982. His brilliant academic career was only marred by a few B-grades for Marxist political economy and English.

Geim was turned down when he applied first to another Moscow university specialising in engineering and physics, and worked as a machinist at a factory making electrical instruments for eight months.

Given the increasing emphasis on marks, in Canadian universities at least, I noticed that Novoselov was not a straight-A student. As for Geim, it seems the fact that his father was German posed a problem. (You can find more details in the physorg.com article.)

As for levitating frogs, I first found this information in particle physicist Jon Butterworth’s October 5, 2010 posting on his Guardian blog,

Geim is also well known (or as his web page puts it “notorious”) for levitating frogs. This is a demonstration of the peculiar fact that all materials have some magnetism, albeit very weak in most cases, and that if you put them in a high enough magnetic field you can see the effects – and make them fly.

Why frogs? Well, no frogs were harmed in the experiments. But also, magnetism is a hugely important topic in physics that can seem a little dry to students …

I hunted down a video of the levitating frog on youtube,

As a particle physicist, Butterworth notes that the graphene work is outside his area of expertise so if you’re looking for a good, general explanation with some science detail added in for good measure, I’d suggest reading his succinct description.

Using Shrinky Dinks for SANE nanopatterning

I’m charmed. Scientists at a Northwestern University laboratory have taken to using a children’s arts and crafts product, Shrinky Dinks, for a new way to create large area nanoscale patterns on the cheap. First, something more about the Shrinky Dinks (from their website),

We are the Originators and Manufacturers of SHRINKY DINKS shrinkable plastics.

The very first SHRINKY DINKS were sold on October 17, 1973 at Brookfield Square Shopping Mall in Brookfield Wisconsin. Since that time there has been over 250 different Toy Activity and Craft Kits created and marketed.

SHRINKY DINKS SHRINK to approximately 1/3rd their original size and actually become 9 times thicker. Simply place the SHRINKY DINKS piece you created into a Home Oven or Toaster Oven for 2 magic minutes. Watch as your creation gets smaller and smaller.

It’s “MAGICAL” and it’s so quick and easy to do!

There’s also a video (sadly I can’t embed it here)  about the origins, some very simple science, and ideas on how to use Shrinky Dinks.

As for the scientists, there’s no word on how they decided to use this  product for their work (from the news item on physorg.com),

“Anyone needing access to large-area nanoscale patterns on the cheap could benefit from this method,” said Teri W. Odom, associate professor of chemistry and Dow Chemical Company Research Professor in the Weinberg College of Arts and Sciences. Odom led the research. “It is a simple, low-cost and high-throughput nanopatterning method that can be done in any laboratory.”

Details of the solvent-assisted nanoscale embossing (SANE) method are published by the journal Nano Letters. The work also will appear as the cover story of the journal’s February 2011 issue.

The method offers unprecedented opportunities to manipulate the electronic, photonic and magnetic properties of nanomaterials. It also easily controls a pattern’s size and symmetry and can be used to produce millions of copies of the pattern over a large area. Potential applications include devices that take advantage of nanoscale patterns, such as solar cells, high-density displays, computers and chemical and biological sensors.

“No other existing nanopatterning method can both prototype arbitrary patterns with small separations and reproduce them over six-inch wafers for less than $100,” Odom said.

ETA Aug. 17, 2010: I emailed the originator of Shrinky Dinks, Betty J. Morris asking her how she came up with the name for her product yesterday. Here is her very kind reply,

You were wondering how we came up with the name Shrinky Dinks…To be honest, we were trying to come up with a name that would describe the process…the pieces “shrink” and they become “small”… what are words that mean small…one of the words we came up with was “dinky”…we thought of Shrink Dinky…Shrink Dinkies…Shrinkie Dinkies but ultimately liked the sound of Shrinky Dinks…it was just trying out different words that we thought might be unique and worthy of getting a Trademark…our product has now been on the market 37 years…we have Shrinky Dinks Trademarks in 42 different countries and there have been over 250 different SD kits created and marketed over the years…who would have ever imagined such a success story… not me…that’s for sure!

The story reminds me of how one writes a poem, playing with words.  As Betty says it is a remarkable story and, for me, the science (nanopaterning)/kid’s play (Shrinky Dinks) connection is the best part.

ETA Aug.17.10: I also contacted Teri W. Odom, professor at Northwestern University about why they use Slinky Dinks in their work. She very kindly responded with this:

Part of what we are interested in is the development of low-cost nanofabrication tools that can create macroscale areas of nanoscale patterns in a single step. For a variety of reasons, this end-product is hard to obtain—even though we and others have chipped away at this problem for years.

As an example, to achieve smaller and smaller separations between patterns, either expensive, top-down serial tools (such as electron beam lithography or scanning probe techniques) or bottom-up assembly methods need to be used. However, the former cannot easily create large areas of patterns, and the latter cannot readily control the separations of patterns.

We needed a way to obtain nanopatterns separated by specific distances on-demand. Here is where the Shrinky Dinks material comes in. My student had read a paper (published in 2007 in Lab on a Chip) about how this material was used to make microscale patterns starting from a pattern printed using a laser printer. I imagine his thought was: if this material could be used for microscale patterns, why not for nanoscale ones? It would be cheap, and it’s easy to order.

So, we combined this substrate with our new molding method—solvent assisted nanoscale embossing (SANE)—and could now heat the material to shrink the spacing between patterns. And thus, in some sense, we made available to any lab some of the capabilities of the billion-dollar nanofabrication industry for less than one-hundred dollars.

There is something pleasing about using an everyday, inexpensive product for high end technology. Brava!

ETA Aug.23.10: Michael Berger has written an in depth article at Nanoterk on this type of nanofabrication which includes an interview with Teri Odom.