Grasping Nanotech Is A Piece Of Cake With Physicist’s “Twinkie Guide”

Andrew Maynard, Ph.D., chief science advisor to the Project on Emerging Nanotechnologies, delivers a lesson on nanotechnology by drawing comparisons to a beloved American snack cake in his video presentation, "The Twinkie Guide to Nanotechnology."

In the video, posted on the project's Web site, Maynard actually serves up not one but five nano-lessons designed to impress on the layperson the promises and pitfalls of nanotechnology, which increasingly - albeit discreetly - is being incorporated into consumer products.

First, however, Maynard takes a moment to drive home exactly how small the nano realm is.

A Twinkie, he notes, is roughly 10 centimeters long, the head of a pin slightly larger than one millimeter. "Going down much smaller," he says, "a human hair is between 50 and 100 micrometers in diameter," and "the red blood cell taking oxygen around your body is about six micrometers."

"And then we begin to get really small, down into the nano range," where materials are measured in billionths of a meter, Maynard says.

"Here we have welding fume particles - the smoke produced when you weld - and these particles are [approximately] 100 nanometers in diameter." Smaller still are DNA molecules, which measure approximately two nanometers in diameter, he adds.

In relative terms, "going from the human scale down to the nano scale is the equivalent of going from something the size of the moon down to something the size of a Twinkie," Maynard says.

Lesson 1: Nanotech Is More Than Sum Of Its Parts

Nanotechnology, like a Twinkie, is more than the sum of its parts, according to Maynard, who earned his doctorate in ultrafine aerosol analysis at the Cavendish Laboratory, Cambridge University (UK).

"A Twinkie contains something in excess of 25 to 28 individual ingredients. And I can guarantee that if you took any of those ingredients and had a taste of it, it would not taste like a Twinkie," he remarks.

The same goes for nanotechnology, Maynard suggests, insofar as its ingredients in and of themselves may not be as relevant to the final product as the way they are engineered.

Maynard told "The Rose Sheet" Nov. 14 that an appreciation of this lesson is critical to nanotechnology's appropriate regulation.

For example, zinc oxide can be engineered into a variety of intricate shapes to effect different behavior for different applications. At least one application of nano-sized zinc oxide has been noted in sunscreens (¹ (Also see "Nanotech Regulation Issue Clouded By Friends Of The Earth Sunscreen Guide" - Pink Sheet, 10 Sep, 2007.), p. 15).

"The assumption is often - when it comes to regulation - that you can find out everything you need to know [about a nanomaterial] just by looking at the chemistry of the material. But what a nanomaterial does is a product of all the different factors - it's the chemistry, it's the shape, it's the size, it's everything else," he said.

"So if you ignore all those other parts and focus solely on the chemistry you're going to miss something, just like if you develop your idea of what a Twinkie tastes like by tasting just the flour or the water or the eggs, you're going to miss quite a lot of important stuff."

Lesson 2: Carpe Diem!

"Carpe diem, seize the day," Maynard says. "If you see something that's good, take advantage of it."

Citing the uncontestable appeal of the Twinkie, the physicist goes on to list a number of potential benefits that make nanotechnology similarly attractive.

"This is a technology that I would call an 'I wish' technology," he says. "I call it that because it's a technology that allows us to take something that is OK but maybe not brilliant and improve it."

For example, sunscreens are being formulated with nano-particles to address consumer complaints about products that are conspicuously white when applied.

"You may say, 'I wish this sunscreen went on better, went on clearer, wasn't so sticky.' ... Nanotechnology can fix that," Maynard says.

Similarly, nanotechnology allows for the creation of socks that are odorless and portable media players that can store more songs, he notes.

In terms of societal benefits, nanotechnology offers the prospect of building materials that are "light as plastic [but] strong as steel" and likely will have important applications in energy production and storage, particularly in the creation of more powerful, longer-lasting batteries.

The science also promises to enable the production of clean water "almost anywhere we go, on demand," according to Maynard.

Medicine also is being taken to new levels with nanotechnology, he says. Drug-based cancer therapies in development, for instance, allow physicians to "target the disease without the adverse side effects that we're so used to with systemic medicines."

Finally, nanotechnology is expected to have tremendous commercial benefits, Maynard points out. The global market for products based on nanotechnology is projected to reach $2.6 trillion by 2014, he says.

Lesson 3: With Benefits Come Risks

"Too much of a good thing" - Twinkies included - "isn't always for the best," Maynard notes.

He references animal research from the University of Rochester to illustrate the unique risks posed by nano-particles, which have been observed to behave differently than their macro-size counterparts.

Conventional airborne particles inhaled in rat studies are known to deposit in the animal's lungs, Maynard explains, but nano-size particles of manganese oxide were discovered by University of Rochester researchers to deposit elsewhere - in the brain.

"This has been shown to happen in animals; we have no idea whether it happens in humans. Even if it does, we don't know whether it's important."

However, "it does demonstrate that some of these new materials do behave in different ways, and we've got to ask some serious questions about ... what the impact of that behavior might be," Maynard says.

Research must be conducted on both the toxicity and exposure levels of nano-materials, because "unfortunately when you go through the exercise of saying 'how much information do we have in each of these areas,' the answer is, 'not a lot.'"

Lesson 4: Public Perception Matters

Pointing to an image of a "rather mangled Twinkie," Maynard says: "I tried to persuade my son to eat this Twinkie and he gave me the weirdest look you've ever seen - 'You really want me to eat this thing?'"

"Anything that is perceived as being bad or doesn't look good, people are very suspicious about," he continues. "The same goes for nanotechnology."

According to Maynard, surveys conducted by the Woodrow Wilson Center for Scholars' Project on Emerging Nanotechnologies have revealed a "reasonably even balance" between people who think the potential benefits of nanotechnology outweigh the risks and people who feel otherwise.

But what is clear is that consumers "want greater transparency, which means if industry's developing and using nanotechnologies, people want to know. They want to know what the benefits are, what this technology does for them, and what the possible downsides are and how they can avoid these downsides."

Currently, PEN has noticed marketers, especially in the United States, "veering away" from advertising their use of nanotechnology, Maynard says. "They've removed the word 'nano' from their marketing information."

Lesson 5: The Nano-Enhanced Super-Twinkie

For his final lesson, Maynard speculates on how nanotechnology could conceivably improve the Twinkie on four counts: ingredients, processing, security and packaging.

First, nanotechnology could potentially serve to "retain the texture, the feel" of the Twinkie's cream, but reduce the calories, Maynard suggests. "This is something we can do by putting nano-capsules in there which just have the fat on the outside but not on the inside," he says.

Second, nanotechnology could help in minimizing the energy required to process Twinkies. Roughly 500 million Twinkies are made each year, Maynard says.

"That means if you take the cream in each of these Twinkies and you were to lay it out in a continuous stream, it would be over 30,000 miles of Twinkie cream. That's enough to go around the world once and then a little bit more," he notes.

"Now imagine squeezing all that cream through the processing pipe they use to make these - it's going to take a horrendous amount of energy."

However, energy could be conserved by coating the inside of the processing pipe with a nano-surface so repellent to liquids that the Twinkie cream "would just slip beautifully through without any resistance."

Third, nanotechnology could be of use in signaling when the Twinkie has gone bad. While there have been rumors that Twinkies have a shelf-life of decades, Maynard reveals that they actually have a shelf-life of 25 days.

A fourth and related use of nanotechnology pertains to packaging, Maynard says. Better, nano-enhanced packaging could conceivably extend the shelf-life of a Twinkie by keeping out "the bad stuff," such as oxygen, while keeping in moisture and "the good stuff."

In an interview, Maynard said applying the same speculative exercise to personal care is difficult, but that one thing is almost certain: "Simply because nanotechnology does give us this dexterity to play around with atoms and molecules in a way we haven't been able to do before, you will see some fairly advanced uses in that field."

"We can begin to engineer things to get over some of the limitations of current products," he concluded.

Currently, PEN has identified nearly 600 consumer products with claims to nanotechnology, many of them in the personal-care sector.

In addition to nano-particles employed in sunscreens, PEN has encountered anti-aging products that reduce the appearance of wrinkles by forming "a network of almost threads on the surface of the skin, and those threads are anchored by nanoparticles and then pull the skin together to tighten it up," among other applications, Maynard indicated.

- Ryan Nelson ([email protected])