Mark Grubelich, the lead developer of the grenade, said Friday it's basically a fuel-air explosive, similar to the weapons employed to attack cave complexes and troop concentrations in Afghanistan.
"It's not a 1,200-pound bomb, though, it's only got about 20 grams of (flash powder) in it," Grubelich told United Press International. "Conventional flash-bangs use about 17.5 grams of flash powder."
Even though more material is used, the new grenade is safer because it doesn't pre-mix the powder with oxygen. Instead, the Sandia device sprays the powder out of its plastic body into a cloud about five feet across, then detonates it using the oxygen present in the atmosphere, Grubelich said.
The difference is crucial when it comes to protecting hostages or suspects from unintended injuries, he said. When today's flash-bangs detonate, a pressure wave of about 30,000 psi is created.
"If you've got that device in your hand, or against your chest or back or head, what you did is just blow up a small bomb in close proximity to your body," Grubelich said.
The Sandia device only creates about 10 psi at the center of its explosion, yet still creates the desired intense light and thunderclap of noise that disorients potentially hostile people long enough for police to rush in and control a situation.
The new grenade also could present a much smaller fire hazard, Grubelich said. Existing devices often have cardboard bodies that can leave smoldering debris, or still-burning powder can burn on surfaces. The Sandia flashbang doesn't leave behind such problems, he said.
"What you do locally is consume the oxygen," Grubelich said. "The only thing that we (leave behind) is excess fuel, and there's nothing to burn it with."
Grubelich pointed out, however, that fire dangers would still be present in situations involving explosive vapors.
Another plus is that the device is reusable; all users need to do is put another dose of powder in there. Since the powder needs to be spread into a cloud in order to become explosive, unauthorized users wouldn't be able to build an improvised bomb out of it, Grubelich said.
The Sandia team has done a very good job of improving the technology of distractive devices, said John Alexander, a longtime researcher and military adviser credited with developing the idea of non-lethal defenses. The new flashbang should be particularly effective in hostage situations involving small rooms, he said.
"The outcome of the mission is what's important -- am I going to get the hostages out alive?" Alexander told UPI. "With somebody trying to do a suicide by cop, for instance, you want to minimize the damage and increase the probability of success."
People shouldn't worry about the Sandia device suffocating people by using up all the oxygen in a room, Alexander said. There will be an opening into the room to toss the grenade in, and you need more oxygen to ignite the powder than you do to sustain life, he said.
The next step in this area of research, Alexander said, would be to try and momentarily stun another sense organ -- adding a overpowering smell to the flash and bang, for example.