Apparatus for pneumatic shuttering of an aerosol particle stream
| DWPI Title: Apparatus for pneumatically shuttering of aerosol particle stream in pharmaceutical aerosol delivery, has pneumatic shutter with gas flow to shutter collimated aerosol particle stream exiting exit nozzle away from fluid axis |
| 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. |
| Use: Apparatus for pneumatically shuttering of aerosol particle stream use in many fields, including pharmaceutical aerosol delivery and additive manufacturing. |
| Advantage: The shuttering can be used to divert the resulting droplet stream according to a programmed schedule, thus interrupting the deposition process and enabling fabrication of discreet structures. The apparatus allows for constant material production during the shuttering process, so that precise and reliable deposition is provided. The shutter gas and vacuum flow rates are then adjusted to minimize pressure perturbations when the shutter is opened and to quickly return to normal operating pressure when the shutter is closed. The laser-jet configuration allows for controlled heating and evaporation of the deposited liquid while minimizing heating of a transparent or nearly transparent, or opaque substrate. Since increasing the viscosity of the liquid just above the deposition zone changes the fluid dynamics, thus uncontrolled spreading and even splashing is eliminated. The invention can also be used to build three-dimensional structures using a layer-wise process, wherein simple and complex objects are printed directly from a computer-automated drawing (CAD) file. |
| Novelty: The apparatus has an aerosol generator for generating an aerosol stream of particles. A print head (10) has an aerodynamic lens system having two aerodynamic lenses with a sheath gas flow for collimating the aerosol particle stream prior to exiting through an exit nozzle. A pneumatic shutter (20) has a gas flow perpendicular to the flow axis of the collimated aerosol particle stream to shutter the collimated aerosol particle stream exiting the exit nozzle away from the flow axis according to a programmed schedule. A decoupling volume (16) is formed between the print head and the pneumatic shutter for decoupling the pressure in the print head from the pressure in the pneumatic shutter. |
| Filed: 2/27/2017 |
| Application Number: US15443867A |
| Tech ID: SD 13629.1 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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