Two specialty companies, ITT Exelis (McLean, VA) and Altapure (Tomahawk, WI), have developed a sterilization system that uses a uniquely different technology than other systems on the market. 
The device relies on a piezoelectric ceramic-based nebulizer that generates a heavy cloud of sub-micron droplets that kill everything they get to. The technology seems to be intended for sterilization of large spaces, including compromised buildings and military aircraft that serve as air hospitals.
More from Altapure’s technology page:
Altapure droplets are so small that USSMD has successfully sterilized resistant spore strips inside medical sterilization packaging in about 20 minutes while leaving essentially no residue. The company’s first application of the technology is focused in the area of sterilization and high level disinfection. Altapure’s technology is small, compact and nearly silent. This makes possible the creation of a portable/mobile units or small footprint fixed unit aerosol generator capable of delivering a sterilant containing only environmentally friendly and EPA approved agents for the purpose of local high level disinfection (medical cold sterilization), “clean room” disinfection, area disinfections, or remediation of local or distant areas contaminated by bacteria or virus including bio-terrorism agents.
While gases also possess diffusion and penetration capability, the sparse nature of individual gas molecules in the air are exponentially less effective, requiring the use of high concentrations of dangerous gases and long process times. Altapure’s small droplets take the best of both worlds, imitating the diffusion and penetration capabilities of a gas while maintaining the kill power of a liquid. Yet despite its incredible gas-like diffusion and penetration capability, USSMD are much easier to sequester when required.
Press release: ITT Exelis adapts sonar technology for critical medical, commercial and defense applications