New ‘smart second skin’ for anti-bioweapon suits developed
by Jessica Hall
Researchers from the Lawrence Livermore National Labs have created a new fabric fit for a super-suit that could clothe and protect our soldiers in the battlefield. The new fabric is actually a composite: a creation of layers. It starts with a fabric backing layer that supports a polymer membrane. The membrane is studded with aligned carbon nanotubes that act as moisture-conducting pores. The nanotubes are embedded in the membrane; the researchers also call the membrane a polymer filling, because at that scale, it acts like a layer of polymer foam that lets the nanotubes stay aligned while the fabric is in use.
It all adds up to a shiny new composite fabric with nanopores too small to admit anything larger than 5nm across, which includes many biological or chemical hazards. At the same time, the nanopores are large enough to permit water molecules to pass through. In fact, in testing, the new fabric breathed better than Gore-Tex. That’s probably because their fabric performed better than the theoretical maximum: according to the report from LLNL, their new fabric could “sustain gas-transport rates exceeding that of a well-known diffusion theory by more than one order of magnitude.”
Some chemical weapons are smaller in size than 5nm, though, and could still conceivably get in through the pores. 5nm is only 50 angstroms, meaning readily homebrewed chlorine gas could probably float right in through those pores on the concentration gradient alone. Undaunted, LLNL scientists and collaborators are moving forward with prototyping a version of the fabric that can actively respond to bioweapons and chemical threats.
“The material will be like a smart second skin that responds to the environment,” said Kuang Jen Wu, of LLNL. The fabric will be able to block chemical threats like sulfur mustard (a blister agent), GD and VX nerve agents, toxins such as staphylococcal enterotoxin, and even spores like anthrax.
To create a membrane capable of an active response, the scientists are modifying the surface of the membranes with functional groups that react to known chemical threats. They say the functional groups will sense and block the threat like gatekeepers at the nanotube apertures. It might make some part of the biohazard super-suit consumable or single-use-only, but what price the safety of soldiers or responders to a chemical spill? In any case, no matter who wears the suit, it’s important to remember one thing: No capes!
Originally published at www.extremetech.com.