The Army’s research and development arm has funded a three-year research program at University of California, San Diego investigating nanofoam for protection -- the first foam armor endeavor ever, the college said.
"We’re developing nanofoams that help disperse the force of an impact over a wider area,” explained UC San Diego professor of structural engineering Yu Qiao. "They will appear to be less rigid but will actually be more resistant than ordinary foams."
Qiao’s nanofoam may someday protect soldiers’ brains from blast trauma and prevent blast-induced lung injury. It may also be used to protect buildings from blasts.
But just what is a nanofoam?
Standard foam you might find guarding that Amazon.com purchase doesn’t provide protection against impacts or blasts. When run-of-the-mill foam is struck, the energy is absorbed in one localized area.
If nanofoam receives a blast, however, it absorbs the impact energy over a wider area making it way more resistant. The team’s nanofoam has a porous structure like honeycomb, making the new material very light.
Part of their research involves working out the ideal pore size to absorb energy from impacts. Qiao has considered pore sizes ranging from super tiny (just 10 nanometers across) to the still-tiny 10 microns. Early testing suggests that the material performs best when the pores are tens of nanometers in size.
The team creates the nanofoam by mixing two materials together at the molecular level. One material is then removed using “acid etching” or combustion. The process creates channels at a microscopic level. In the final step, the material is dry cured.
The team tested the nanofoam to see how much energy it could absorb from an impact, putting it in a testing rig powered by a gas gun and slamming it with increasing force.
To examine and evaluate the damage, they used a scanning electron microscope.
The research is promising, the team says; they plan to provide their results at an upcoming a research expo April 18 at UC San Diego.
During the next two years, the research team plans to manufacture and test metallic and polymeric nanomaterials.