Cornstarch and water is a smart material derived from simple components. This video shows a bowling ball bouncing off the surface of the mixture, which also can catch a dropped egg without breaking it.
(Photo Credit: Heinrich Jaeger/University of Chicago)
This seven-second video shows a narrow aluminum rod striking the surface of a cornstarch and water mixture at a speed of one meter (3.2 feet) per second. Recorded at 10,000 frames per second with a high-speed camera, the video shows that the rod creates a bowl-like depression around the impact site but fails to penetrate the surface of the fluidic mixture.
(Photo Credit: Scott Waitukaitis/University of Chicago)
Source: University of Chicago