Dive summary:

• It may be that buildings with high security demands, including the ability to withstand nearby explosions, will be clad in a new type of foam developed by structural engineers at the University of California San Diego.
• The material is called nanofoam because the empty pores in the material seem to work best at dispersing energy when they are in the range of tens of nanometers.
• The experiments sponsored by the Army are ongoing, using an air-powered gun to send blasts against various foams, but the researchers in Prof. Yu Qiao's lab are confident enough in the results to present them at a research expo on the campus later this month.

From the article:

The nanofoams are made up of a honeycomb, or porous, structure and are very light -- pores make up anywhere from 50% to 80% of the structure. ...