Abstract: Direct slicing of CAD models to generate process planning instructions for solid freeform fabrication may overcome inherent disadvantages of using STL format in terms of the process accuracy, ease of file management, and incorporation of multiple materials. This paper will present the results of our development of a direct slicing algorithm for layered freeform fabrication. The direct slicing algorithm was based on a neutral, international standard (ISO 10303) STEP-formatted NURBS geometric representation and is intended to be independent of any commercial CAD software. The following aspects of the development effort will be presented: 1) Determination of optimal build direction based upon STEP-based NURBS models; 2) Adaptive subdivision of NURBS data for geometric refinement; and 3) Ray-casting slice generation into sets of raster patterns.

Abstract: A drug delivery device such as an oral dosage form (ODF) with a toxic or potent core encapsulated by a non-toxic region. The non-toxic region may be a region including multiple layers, coatings, shells, and combinations thereof, which provides protection to and isolation from the toxic or potent core. The drug in the toxic or potent core is incorporated into the dosage form via, for example, three-dimensional printing, as a solution, solubilization or suspension of solid particles in liquid, rather than by the more conventional handling and compressing of dry powder. This minimizes the likelihood of creating airborne particles of the toxic drug during manufacturing, hence controlling and minimizing the exposure of manufacturing personnel to the hazardous substance. Wet dispensing of the toxic or potent drug further provides greater bioavailability of the drug to the patient.

Abstract: The invention includes a three-dimensional printing (3DP) machine that has at least one ultraviolet (UV) light source directed at powder or slurry being processed by the 3DP machine and/or directed at any of various surfaces or machine components, in a manner suitable to kill or damage microorganisms to a desired extent. The UV light sources may be either stationary or movable, and may be either pulsed or substantially continuous, and may operate in any desired sequence and timing with respect to other operations performed by the machine. The invention may include ultraviolet illumination in such a way as to interact with powder to sterilize or disinfect powder either while the powder is stationary or, alternatively, as powder is being moved from one place to another within the 3DP machine, or both. The invention also includes methods of performing three-dimensional printing using such illumination.