A Practical Use for Oobleck
Students fill a pothole with non-Newtonian fluid. Photo: Lisa DeJong, The Plain Dealer
Remember playing with oobleck in science lab? The strange material that can shift between liquid and solid properties, called a non-Newtonian fluid, is incredibly simple to make out of cornstarch and water. It exhibits liquid properties when moved slowly, but becomes stiff when rapid pressure is applied. Although oobleck—which earned its name from a Dr. Seuss story—evokes surprise in a high school classroom, it doesn't immediately conjure ideas for practical applications.
Engineering students at Cleveland's Case Western Reserve University have developed a clever use for the material, however: filling potholes. Determined to find a fix for a perennial problem, the students thought of a non-Newtonian fluid—in particular, a shear-thickening fluid as described above—because of its ability to fill irregularly-shaped depressions yet become rigid in the presence of passing automobiles. "When there's no force being applied to it, it flows like a liquid does and fills in the holes," says team-member Curtis Obert, "but when it gets run over, it acts like a solid."
The students tried out many formulations of the oobleck material before arriving at the desired particle density. They propose supplying road crews with waterproof bags filled with the fluid—topped with black concealment fabric—as a temporary solution until more permanent patches can be made. According to team member Mayank Saksena, "We definitely don't want people avoiding them."
Check out the students' working demonstration of the pothole patch on YouTube.