As blogged about by the Arxiv Blog, sound, or “acoustic trapping,” can be used to filter bacterial spores from water, according to a new set of experiments funded by the U.S. Army.
Filtering water is trickier than it sounds, because so far most water filters have been designed to filter only certain shapes of bacteria or chemically attack certain types. Both require intenstive human intervention.
“The U.S. Army is funding a project to determine whether sound can help. The idea is to allow the water to flow through a cavity in which a transducer sets up an acoustic standing wave. Any bacterial spores in the water are then subjected to three forces: buoyancy/gravity, the drag of the fluid as flows along and the acoustic pressure from the standing wave.”