Reusable explosive device to help law enforcement

Scientists at the US Department of Energy’s Sandia National laboratories have developed a cheaper, non-lethal way to stun kidnappers or terrorists holding hostages.

The device, developed by Sandia researcher Mark Grubelich, is said to create a blinding, deafening, yet ultimately harmless explosion when lobbed into a room.

Unlike earlier versions that ignite from concentrated materials, the explosive source in this device fans out as an airborne powder before it ignites, making it less dangerous to hostages. The stun grenade is also reusable, making it feasible as a training tool.

Stun grenades, known formerly as diversionary devices, are used in interventions practised by most US police departments. However, most devices currently in widespread use contain a metal powder that violently combines with a salt containing oxygen.

When a grenade-style fuse ignites this mixture -aluminium and potassium perchlorate -, an explosion takes place within the body of the device. This creates a zone of extreme pressure nearby that may be dangerous if the device lands near a hostage’s neck or head. The explosion also destroys the shell of the device containing the explosive, making such apparatuses expensive to use as training tools.

The new device is made of plastic. It contains only metal powder and no oxidiser and no explosion takes place within the canister. Instead of ignition within the device, the particles are forced like a burst of talcum powder out through 16 quarter-inch-diameter holes in the bottom of the structure.

The ejected particles form a sheet of metal dust about five feet in diameter before igniting by combining with oxygen present in the atmosphere. The distributed powder means that the pressure in the immediate vicinity of the exploded device is lowered to a safer level.

It also means that the canister is undamaged and can be reloaded relatively cheaply, making it easy to use as a training device.