Disappearing actDevice Vanishes on Command after Military Missions

A polymer that self-destructs? While once a fictional idea, new polymers now exist that are rugged enough to ferry packages or sensors into hostile territory and vaporize immediately upon a military mission’s completion. The material has been made into a rigid-winged glider and a nylon-like parachute fabric for airborne delivery across distances of a hundred miles or more. It could also be used someday in building materials or environmental sensors.

The researchers presented their results Monday, 26 August, at the American Chemical Society (ACS) Fall 2019 National Meeting & Exposition. ACS is holding the meeting here through Thursday. It features more than 9,500 presentations on a wide range of science topics.

A brand-new video on the research is available at www.acs.org/HLS_Disappearing_Glider.

“This is not the kind of thing that slowly degrades over a year, like the biodegradable plastics that consumers might be familiar with,” says Paul Kohl, Ph.D., whose team developed the material. “This polymer disappears in an instant when you push a button to trigger an internal mechanism or the sun hits it.” The disappearing polymers were developed for the Department of Defense, which is interested in deploying electronic sensors and delivery vehicles that leave no trace of their existence after use, thus avoiding discovery and alleviating the need for device recovery.

ACS says that the key to making a polymer disappear, or break apart, is “ceiling temperature.” Below the ceiling temperature, a polymer configuration is favored, but above that temperature, the polymer will break apart into its component monomers. Common polymers, like polystyrene, have a ceiling temperature above ambient temperature and are very stable. And even when they are warmed above their ceiling temperature, some of these materials can take a long time to decompose.