Oobleck! It’s one of Arizona Science Center’s favorite non-Newtonian substances and it’s so easy to make at home. Just mix a good amount of cornstarch with a tiny bit of water until a thick paste forms and, eureka! You’ve created a wacky goo that behaves both as a liquid and a solid. However, did you know that scientists are actually looking to use substances like Oobleck to create better body armor? If you’ve ever played with Oobleck, you’ve probably noticed that when you quickly strike it with your hands, it is very solid. And who can forget those crazy folks running across pools of the stuff? Oobleck firms up like a solid when pressure is applied. When there is no pressure, it flows like a liquid. Researchers are interested in this property and have created other sheer-thickening fluids (STFs) that behave just like Oobleck. These STFs are being used to make new gels and fabrics that are flexible and comfortable to wear when no force is applied but when struck, they quickly harden to provide solid protection.
A perfect example of this technology is the Liquid Body Armor created by the University of Delaware and the U.S. Army Research Laboratory. Liquid Body Armor is Kevlar saturated by a mixture of nano-sized silica and polyethylene glycol. In a liquid state, the nano-silica particles stay evenly separated but if the Kevlar is hit forcefully, the impact forces the nano-silica particles into small groups called hydroclusters. This hardening only takes milliseconds but once the force is removed, the Kevlar returns to its original flexible state. This amazing new material is still in its experimental phases but it could someday replace traditional military flak jackets or could be used for prison guard uniforms. Other STF-treated fabrics like the nano-silica treated Kevlar are currently being used to make impact-resistant sportswear such as ski hats, football pads, motorcycle jackets, and running shoes. Nanotechnology is out there and it is making our world safer!
To learn more about the cool innovations produced by nanoscientists, visit Arizona Science Center and attend our NanoDay April 5, 2014 or visit http://www.whatisnano.org for more information about nanotechnology.