| Abstract: | The invention provides pneumatic shuttering of a focused or collimated
aerosol particle stream. The aerosol stream can be collimated by an
annular sheath of inert or non-inert gas. The apparatus propagates a
sheathed aerosol stream through a series of aerodynamic lenses along the
axis of a flow cell. The final lens is typically positioned above a
substrate, so that direct material deposition is provided. A
substantially perpendicularly-flowing gas external to the aerodynamic
lens system is used to redirect the particle stream away from the flow
axis and through an exhaust port, thereby shuttering the collimated
aerosol stream. The pneumatic shutter enables printing of discreet
structures, with on/off shuttering times of approximately 1 to 100
milliseconds. |