February 13, 2015 by Ann Haftl
The Drexel University Department of Materials Science and Engineering co-hosted the fifth annual Philly Materials Science and Engineering Day Feb.7 at the Bossone Research Center. The event was led by students and volunteers from Drexel University, the University of Pennsylvania, the Academy of Natural Sciences, the Franklin Institute, the Chemical Heritage Foundation and the
The event showcased nearly 40 demonstrations for all ages in addition to a plethora of “Nano Nookactivities geared toward younger visitors, as well as hands-on workshops for specific age groups. Children were given sheets to stamp at every table at the event to encourage them to see all of the demonstrations.
This year, a few changes to the event organization included color-coding tables demonstrating similar themes together so that children with specific interests could visit tables with the focus on those topics. Another major and popular change was the incorporation of tetrahedral balloon hats. According to Christopher Weyant, a professor in Drexel’s College of Engineering and the leader behind the event, balloons had been used in the past to create a giant, materials-related structure in a portion of the room throughout the course of the day. He said that kids would walk up, expecting to receive a balloon to carry around and would walk away disappointed. “So this year we’re making tetrahedra that kids can wear on their heads, which they are,” Weyant said. Tetrahedral structures, he explained, are key in materials science due to their stability and wide variety in nature.
On a more serious note, Weyant discussed the importance of the students who volunteered their time to make the Philly Materials Day possible. Michelle Marcolongo, another Drexel professor helping to direct the event, added that the student volunteers “really like being able to explain some complicated science [to the children] in layman’s terms.”
One popular demonstration table allowed kids to make their very own bouncy balls from relatively simple, household ingredients: glue, cornstarch, food coloring and borax (which is used in dish soaps).. The cornstarch and glue are both composed of long polymer chains of molecules, and the borax acts as a cross-linker to connect the tangled polymer chains in structural forms, creating the rubbery and bouncy end product.
Jared Ely, a senior materials science major, turned from the chaos to comment, “This is so much fun.” Ely worked the bouncy ball table for two hours in the afternoon after helping in the Nano Nook for the first part of the event. He explained that the reason the final step was so tricky was that the children didn’t roll the ball into a form fast enough — they got it stuck to their hands instead. The substance is non-Newtonian, meaning it has to be “hit hard” to become a solid: the magic step in the process. Ely has participated in Philly Materials Day every year since its start at Drexel in his freshman year.
Another popular demonstration with non-Newtonian fluids was a pit of “oobleck,” a mixture of cornstarch and water. Kids who ran barefoot quickly across the surface of the liquid could make it across the pit without sinking into the liquid. But if they stood still, slowly their feet would disappear into the gooey fluid.
The showstopper, however, was the liquid nitrogen ice cream demonstration — complete with sprinkles, chocolate sauce, candy pieces and other sundae toppings for the children to pile onto their scientific frozen treats. A mixture of cream, sugar and vanilla was prepared and then frozen on contact by liquid nitrogen. This was carefully dispensed from a canister that maintained the -320 degree Fahrenheit temperature required to keep the nitrogen in the liquid state. The Drexel volunteers running the table all agreed that it was the most popular demonstration of the day. However, they were also baffled that all of the children left the table as soon as they were given their ice cream.
Sophomore materials science major Karen Wells said, “It’s been really cool [volunteering] … The amount of kids who actually come here and know about science is incredible. … I think it’s also cool to see the parents get into it.”
At another table, freshmen materials science majors Jeremy Pitock, Maria Lefchak and Gary Saporetti helped out at a table focused on differing structures and their varying strength. They agreed that the main point of the event was to be “an outreach program to expose kids to materials engineering,” as Pitock put it.
Lefchak came to the event for the first time during her sophomore year in high school, without any previous interest or knowledge in materials science. She commented that the event was a good way to introduce materials science to the public as the little known engineering field. “People mostly know about mechanical [and] chemical engineering, so it’s a good way to get kids exposed to it since materials is everything. … They say it’s the science of stuff. It’s a little more fun than the others,” Lefchak joked.