Balloons that Smell

During the fall quarter, I sacrificed a few Tuesday and Thursday nights to volunteer for the Family Ultimate Science Experience (FUSE) hosted by the Center for Science and Engineering Partnerships (CSEP) at UCSB. FUSE hosts science nights at various junior high schools in the community and invites students and their parents to a night of exploration and discovery. I grew up watching and helping my parents volunteer for Christmas shopping sprees for underprivileged children, Earth Day festivals, and 4th of July parades, which fostered my own desire to undertake similar endeavors as I’ve grown older.

I eagerly volunteered to help host FUSE, where I had the chance to demonstrate chemical reactions by leading the “classic volcano” experiment, an acid/base color change experiment, and an “elephant toothpaste” experiment. Volunteering left me feeling fulfilled and accomplished. The many thank you’s from parents and the hope that I may have helped spark an interest in science encouraged me further to find more related opportunities. So when I received an email asking for volunteers for this year’s NanoDays, I signed up myself – and decided to drag Kierstin along with me.

NanoDays is an international event designed to inform and educate the general population on emerging “nano” technology. Nano is merely a prefix that indicates a billionth (10-9). A nanometer is a billion times smaller than a meter (or, for reference, nearly 1000 times smaller than the diameter of a human hair). Nanotechnology imparts the ability to influence and control atoms or molecules and leads to interesting (and sometimes unexpected) properties. Those unfamiliar with nanotechnology can look towards sunscreen, which has evolved from the white, pasty goo seen caked on the nose of a stereotypical lifeguard to sunscreen with nanoparticles giving a transparent skin-protecting layer. Applications of nanotechnology are not just related to sunscreen. Its uses are ubiquitous, and its full potential remains untapped, which is why the Nanoscale Information Science Education Network (NISE) founded the NanoDays event.

This year’s NanoDays event in Santa Barbara was hosted at the Natural History Museum, which I wrote about in a previous post. Kierstin and I arrived an hour early with the rest of the volunteers to give us time to settle in and learn about our demonstration. We were assigned to the “Exploring Size – Scented Balloons” exhibit. We filled up different colored balloons with various flavor extracts, then inflated the balloons, and hung them on the wall. Visitors to our exhibits could smell the balloons and try to guess which flavor corresponded to a certain balloon color. Of course, we weren’t there just to sound like wine connoisseurs when hinting that they’ll notice, for example, “a late fruity flavor on the nose when smelling the blue balloon” or “hints of a sweet orchid when smelling the yellow balloon”. There was also science to be learned!

Something smells when molecules reach your nose, are detected by “receptors”, and signal to your brain that the something is reminiscent of vanilla. The extract that we placed in the balloon and sealed with a knot must find a way to escape and reach these receptors. There are no visible holes, but molecules can escape through the balloon’s semipermeable membrane (i.e., science jargon for a thin wall with small holes in it). If you’ve ever had a helium balloon for a few days, you may have noticed that the balloon deflates as helium molecules slowly exit the balloon. The size of the scent molecules are on the nanoscale, so this demonstration can help people understand how small “nano” indicates.

SEM image of a plant bug. Each hair on its leg is many nanometers thick.

Electron microscope image of a plant bug. Each hair on its leg is many nanometers thick.

There were other awesome experiments throughout the NanoDays exhibit. There was a semi-portable tabletop electron microscope, which shoots beams of electrons to let people see nanometer-sized samples. Visitors could play with oobleck, a mixture of cornstarch and water, and see how the structure of materials at the nanoscale impacts the material as a whole. The cornstarch and water mixture feels like a liquid when touched softly but a quick punch makes the material behave like a solid. This is similar to how Kevlar body armor is flexible but still strong enough to absorb the impact of gunshots. (Check out this video of people swimming and running on cornstarch and water). A demonstration asked if metals had memory and showed how atomic behavior can make it seem like they do. A stretched alloy of nickel and titanium rearranges its atoms and returns to its original, un-stretched shape – just by adding heat. There were plenty of fascinating activities for visitors of all ages manned by the 30+ NanoDays volunteers.

After four hours of asking kids how they thought the smells reached their noses, as well as discussing nanotechnology with some adults in-the-know, the exhibit closed and we cleaned everything up. It was an exciting day, highlighted by the opportunity to share my own passion and promulgate new technologies and science education. I know I’ll pursue volunteer activities in the future, seeking the fulfillment and satisfaction that comes with making a difference.

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