It was only about 20 years ago that carbon nanotubes, among the stiffest and strongest fibers known, were discovered. Ever since, scientists and academics have been researching potential uses.

You can get an up-close look at the world's largest model of a carbon nanotube, which stretches 100 feet high, inside Drexel University's Bossone Research Center in Philadelphia on Saturday for the second annual Philly Materials Science and Engineering Day.

The free event is open to the public from 10 a.m.-4 p.m. and is presented by Drexel and the University of Pennsylvania. There will be a series of talks and demonstrations that are intended to excite the entire family about the rapidly growing field of materials science and engineering.

Some of the topics slated to be covered include building carbon nanotubes, bioplastics, liquid nitrogen ice cream, sports equipment, "ask an engineer," electronic noses, magic jelly marbles, nanowires, solar-powered cars, and much more.