A researcher at the defense company Boeing has filed a patent for a sci-fi-esque cloaking device that would protect soldiers from intense shock waves generated by explosions. The just-issued patent (No. 8,981,261) to Boeing envisions stopping shock waves using a veil of heated, ionized air. Such a "shield" would damp the force of explosions. It doesn't build an invisible wall of force, but rather makes shock waves bend around objects, just as some high-tech materials bend light and make things invisible.
Brian J. Tillotson, a senior research fellow at Boeing, said the idea occurred to him after noticing the kinds of injuries suffered by soldiers who served in Iraq and Afghanistan. "We were doing a much better job of stopping shrapnel," Tillotson told Live Science. "But they were coming home with brain injuries."
Though the armor plating on a military vehicle might stop the debris from a roadside bomb from injuring a soldier, it can't shield against the shock waves generated by such explosions. The blast wave goes right through a human body and causes massive trauma. (This is why the action-movie scenes where the hero runs ahead of an explosion and escapes harm are pure fiction.)
Tillotson's invention is a device that would heat the air in front of the spot where the bomb goes off. In one version, a detector "sees" an explosion before the shock wave hits. The detector is connected to an arc generator, basically two ends of a circuit connected to a large power source. When the system generates enough current, an arc of electricity jumps between the two ends of the circuit, like a bolt of lightning.
That arc heats and ionizes, or charges, particles of air. The heated air would work as a shield by changing the speed at which shock waves travel, and therefore bending them around a protected soldier, Tillotson said.