The Amazing Aerogel
Aerogel is the lightest known solid.Copyright Jet Propulsion Laboratory, NASA http://stardust.jpl.nasa.gov/photo/aerogel.html
Aerogel, commonly called "frozen smoke," is a super-material with some amazing properties. In this lesson and its associated activity, students learn about this silicon-based solid with a sponge-like structure. Students also learn about density and how aerogel is 99.8% air by volume, making it the lightest solid known to humans! Further, students learn about basic heat transfer and how aerogel is a great thermal insulator, having 39 times more insulation than the best fiberglass insulation. Students also learn about the wide array of aerogel applications.
The man who invented aerogel, Samuel Stephens Kistler, was a chemical engineer who published his findings in a 1931 edition of the journal, Nature. Since then, his discovery has been applied to a wide variety of uses: NASA's aeronautical engineers use aerogel to bring home pieces of comets and dust from outer space, biomedical engineers use aerogel bands to control and maintain people's blood temperatures, and environmental engineers use aerogel to clean up oil and chemical spills. Creative engineers of many specialties take advantage of the extreme properties of the aerogel—high surface area, low density, low thermal conductivity, robustness, etc.—to best suit their designs.
After this lesson, students should be able to:
- Explain the distinctions between transmitting, reflecting and absorbing light waves.
- Describe the differences between opaque, translucent and transparent materials.
- Relate an aerogel property to a new engineering application or idea.