It’s hard to patch up a bleeding wound. If it’s not on a limb, a tourniquet won’t help, gauze doesn’t absorb enough blood, and many blood clotting agents can leave residue behind, resulting in potentially dangerous side effects. A new material that’s bendable, easy to apply and remove, and incredibly absorbent may help fix that.
A found that 80 to 90 per cent of “potentially survivable deaths” of US soldiers who died on the battlefield before they could get to a hospital were due to uncontrolled bleeding. Army researcher Erich Bain and his colleagues set out to make a new type of bandage that would control bleeding better so injured people can make it to hospital for treatment.
Their material starts with a plastic made of polystyrene and rubber, to which acrylic acid is added. The plastic is strong and flexible, so the bandage can be applied to a wound without ripping and removed without leaving any bits behind, and the acrylic acid is extremely absorbent, sucking water out of the blood to help it clot more easily.
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Holding fast
Finally, the material is attached to a gauze bandage containing a clotting agent. In tests, the bandage absorbed 2 to 4 times as much water as the clotting gauze alone – up to 800 per cent of the material’s weight in water. It swelled to its maximum absorption in under a minute.
“A soldier can bleed out in a 2 minute time frame with a bad wound, so once you start to apply this, you really need it to swell extremely rapidly to be effective,” says team member Joseph Lenhart.
The researchers tested the toughness of the bandage by soaking it in water and then stretching it to see how it held up. They found that, depending on the abundances of some of the additives, some samples were up to 4.2 times as tough as the gauze alone, even while absorbing up to 5.7 times as much water.
“It’s a tough material, unlike say, a diaper, which is very absorbent but doesn’t hold together like this material does,” says Bain. “That allows you to pull it out of the wound when it’s time for medical treatment and it comes out.”
It will likely be a few years before the material is used in combat. The team is now working on scaling up the process, and the next step will be animal testing.
Macromolecules
