Engineers at the University of California, San Diego are developing nanofoams that could be used to make better body armor; prevent traumatic brain injury and blast-related lung injuries in soldiers; and protect buildings from impacts and blasts.
The nanofoams are made up of a honeycomb, or porous, structure and are very light — pores make up anywhere from 50 to 80 percent of the structure. Researchers have been trying to determine the optimal pore size to absorb energy from impacts. They have manufactured samples with pore sizes ranging from 10 nanometers to 10 microns.
Preliminary results show that when pore size reaches tens of nanometers, the material seems to perform best. Those samples absorb energy from an impact or blast over a wider area, which makes the material more resistant. By contrast, in ordinary foams, energy is absorbed in one localized area, leading to quick failure.
Samples are placed in a testing rig powered by a gas gun and subjected to increasingly stronger impacts. Researchers then put the samples under a scanning electron microscope to examine the damage. They use extensive data analysis to determine how much energy the nanofoams absorbed during the impact tests.
Also: Basalt fabrics have ballistic properties for potential use in body armor.
