The foam, which is actually a polyurethane polymer, is injected into a patient as two different liquids. When they meet and mix inside the abdominal cavity they expand up to 30 times their original volume and then solidify to stop bleeding and hold everything in place until proper medical care can be administered. The foam can also be easily removed by a surgeon in less than a minute, usually in one solid block that leaves very few fragments behind.
In testing the foam has been found to stop severe haemorrhaging in internal injuries for up to three hours, with a six-fold decrease in blood loss during that time. And the survival rate for patients at the three-hour mark was increased from just 8 per cent to 72 per cent when the foam was administered. And here we thought that stuff was only useful for insulating our homes. [Darpa via Technabob]