System and method for additive manufacture of chemical delivery devices using halftone screening
A method of forming a chemical delivery device with an active chemical includes generating halftoned image data using a stochastic halftone screen and with reference to a concentration parameter for the active chemical. The method also includes ejecting a chemical carrier including the active chemical into a portion of a plurality of cavities formed in the chemical delivery device based on the halftoned image data to produce the chemical delivery device with a concentration of the active chemical corresponding to the concentration parameter.
1. A three-dimensional object printer comprising:
a support member;
at least a first ejector configured to eject a first chemical carrier including a first active chemical toward the support member; and
a controller operatively connected to the at least first ejector and a memory, the controller being configured to:
receive a first concentration parameter for a first active chemical in a first region of a substrate in a chemical delivery device positioned on the support member;
generate halftoned image data using a stochastic halftone screen stored in the memory and with reference to the first concentration parameter, the halftoned image data including a plurality of activated pixels that correspond only to locations of a first portion of a plurality of cavities formed in a substrate that receive the first active chemical; and
operate the at least first ejector to eject a predetermined amount of a first chemical carrier including the first active chemical into each cavity in the first portion of the cavities in the substrate with reference to the halftoned image data to produce the chemical delivery device with a concentration of the first active chemical corresponding to the first concentration parameter.
2. The printer of claim 1 further comprising:
a dispenser configured to emit an excipient material to form the substrate of the chemical delivery device; and
the controller being operatively connected to the dispenser and further configured to:
operate the dispenser to form the substrate from a plurality of layers of the excipient material on the support member prior to the ejection of the predetermined volume of the first chemical carrier including the first active chemical.
3. The printer of claim 2 the dispenser further comprising:
a spreader configured to emit a powdered excipient material toward the support member; and
at least a second ejector configured to eject a liquid binder in a predetermined pattern to bind portions of the excipient material to form the substrate.
4. The printer of claim 1 the dispenser further comprising:
at least a second ejector configured to eject liquid drops of the excipient material toward the support member in a predetermined pattern to form the substrate.
5. The printer of claim 1 , the controller being further configured to:
receive a plurality of concentration parameters of the first active chemical for a plurality of regions of the chemical delivery device;
generate the halftoned image data for the plurality of regions of the chemical delivery device using the stochastic halftone screen stored in the memory with reference to the plurality of concentration parameters; and
operate the at least first ejector to eject the predetermined amount of the first chemical carrier including the first active chemical into the first portion of the cavities in the substrate with a concentration gradient through the plurality of regions of the chemical delivery device corresponding to the plurality of concentration parameters.
6. The printer of claim 1 , further comprising:
at least a second ejector configured to eject a second chemical carrier including a second active chemical toward the support member; and
the controller being operatively connected to the at least second ejector and further configured to:
receive a second concentration parameter for a second active chemical in the first region of the substrate in the chemical delivery device;
generate the halftoned image data using the stochastic halftone screen stored in the memory with reference to the second concentration parameter, the halftoned image data including a second plurality of activated pixels that correspond only to locations of a second portion of the plurality of cavities formed in the substrate that receive the second active chemical, wherein the stochastic halftone screen further comprises a stochastic vector halftone screen; and
operate the at least second ejector to eject a predetermined amount of a second chemical carrier including the second active chemical into each cavity in the second portion of the cavities in the substrate with reference to the halftoned image data to produce the chemical delivery device with a concentration of the second active chemical corresponding to the second concentration parameter.
7. The printer of claim 6 , the controller being further configured to:
generate the second plurality of activated pixels only in locations of the halftoned image data corresponding to cavities in the substrate that do not correspond to any of the first plurality of activated pixels.
8. The printer of claim 1 further comprising:
a dispenser configured to emit an excipient material toward the substrate of the chemical delivery device; and
the controller being operatively connected to the dispenser and further configured to:
operate the dispenser to form excipient material in any cavity in the plurality of cavities that does not receive the first chemical carrier including the first active chemical.
9. The printer of claim 1 further comprising:
a dispenser configured to emit an excipient material toward the substrate of the chemical delivery device; and
the controller being operatively connected to the dispenser and further configured to:
operate the dispenser to form a plurality of layers of an excipient material over the substrate and the plurality of cavities to cover the plurality of cavities and to form another plurality of cavities in another layer of the substrate of the chemical delivery device after the ejection of the predetermined volume of the chemical carrier including the first active chemical.
10. The printer of claim 1 , the controller being further configured to:
generate three-dimensional halftoned image data corresponding to a three-dimensional arrangement of cavities in a plurality of layers of the substrate with reference to the first concentration parameter; and
operate the at least first ejector to eject the predetermined amount of the first chemical carrier including the first active chemical into each of the first portion of the cavities with reference to a two-dimensional arrangement in the three-dimensional halftoned image data corresponding to the plurality of cavities formed in one layer of the substrate.