Patent ID: 8178341

Claim:
A particle exposure system, comprising: an exposure chamber assembly that defines an exposure chamber and includes: at least one fluid outlet; a pedestal having a target-receiving region, said pedestal extending into said exposure chamber so as to space said target-receiving region from said at least one fluid outlet; a target containing viable biological material, said target located upon said pedestal in said target-receiving region; a particle source containing particles having a diameter from about 10 nm to about 1 μm, said particles selected as a function of said biological material in order to study toxicity of said particles on said biological material, wherein said particle source is fluidly connected to said exposure chamber so as to provide said particles to said exposure chamber; a particle charging system operatively configured and located so as to charge said particles with a first electrical charge before said particles enter said exposure chamber from said particle source; a gas supply containing a gas, said gas supply designed, configured, and fluidly connected to said exposure chamber so that said gas carries said particles into said exposure chamber; a first electrode located at least partially within said pedestal; an electrical system operatively connected to said first electrode so as to provide said first electrode with a second electrical charge having a polarity opposite said first electrical charge; and a control system designed and configured for controlling the particle exposure system, wherein said control system is set so that said particles from said particle source are deposited onto said target by electrostatic attraction between said particles and said first electrode substantially only when: said particle charging system is charging said particles with said first electrical charge; said gas is carrying said particles into said exposure chamber; and said first electrode is charged with said second electrical charge.