Abstract: A build plate assembly for a three-dimensional printer includes: a lighting panel having individually addressable pixels configured to selectively emit light and/or transmit light from illumination below the pixels to a top surface top surface of the lighting panel; a rigid, optically transparent, gas-impermeable planar screen or base having an upper surface having an uneven surface topology and a lower surface that is affixed to the top surface of the lighting panel; and a flexible, optically transparent, gas-permeable sheet having upper and lower surfaces, the upper surface comprising a build surface for forming a three-dimensional object, the sheet lower surface positioned opposite the base, wherein the build plate is configured to permit gas flow to the build surface.

Abstract: A stereolithography apparatus includes a light transmissive window defining a build region in which a polymerizable resin can be supported, the window characterized by a transmission spectra curve having a low transmissivity region between first and second high transmissivity regions; a carrier platform positioned above the window; a drive operatively associated with the carrier platform and the window and configured for advancing the window and the carrier platform away from one another; an ultraviolet light source positioned beneath the window; at least one infrared heat source positioned beneath the window; at least one temperature sensor operatively associated with the build region and configured to sense (directly or indirectly) the temperature of a polymerizable resin in the build region; and a temperature controller operatively associated with the temperature sensor and the infrared heat source, the controller configured to intermittently activate the infrared heat source to an elevated temperature at

Abstract: A test cell useful for determining the photosensitivity of a photopolymerizable material, includes a support plate having a top surface portion, a bottom surface portion, and an opening extending therebetween, a light-transmissive base member removably or permanently connected to said bottom surface portion to form with said opening a well, into which well photopolymerizable material can be deposited, and a sensor comprising a thermal sensor, strain sensor, or combination thereof operatively associated with said light-transmissive base member.