An exposure apparatus including a micro light emitting diode display unit and a first projection optical system is provided. The micro light emitting diode display unit has a plurality of micro light emitting diodes. The micro light emitting diode display unit is adapted to individually control light emission signals of the micro light emitting diodes and forming a predetermined pattern. The first projection optical system is disposed on a light emitting path of the micro light emitting diode display unit. The first projection optical system is configured to form an exposure pattern on a photosensitive material layer at once by applying the predetermined pattern.

An artificial structure for promoting microalgae growth includes a 3D-printed structure formed by positioning a printing surface on a movable stage of a 3D bioprinter in contact with a bio-ink that includes a mixture of a pre-polymer material with one or more of cellulose-derived nanocrystals (CNC), and microalgae cells. By projecting modulated light onto the printing surface while moving the stage, the bio-ink is progressively polymerized to define layers of an artificial coral structure with microalgae cells disposed thereon, where the artificial coral structure is configured to scatter light within the structure.

The present invention concerns type II photoinitiators for the free-radical crosslinking of silicone compositions, in particular acrylic silicone compositions. The present invention concerns a silicone composition C1 that can be crosslinked by exposure to radiation with a wavelength of between 300 and 450 nm, comprising: —at least one organopolysiloxane A comprising at least one methacrylate group bonded to a silicon atom, at least one organohydrogenopolysiloxane H comprising at least two, and preferably at least three hydrogen atoms each bonded to different silicon atoms, and—at least one free-radical photoinitiator P. The present invention also concerns the provision of a silicone composition that can be polymerized or crosslinked by free-radical process comprising a type II photoinitiator system suitable for crosslinking silicone compositions, in particular by exposure to radiation, and absorbing light radiation with a wavelength greater than 300 nm.

The present invention concerns type II photoinitiators for the free-radical crosslinking of silicone compositions, in particular acrylic silicone compositions. The present invention concerns a silicone composition C1 that can be crosslinked by exposure to radiation with a wavelength of between 300 and 450 nm, comprising: —at least one organopolysiloxane A comprising at least one methacrylate group bonded to a silicon atom, at least one organohydrogenopolysiloxane H comprising at least two, and preferably at least three hydrogen atoms each bonded to different silicon atoms, and—at least one free-radical photoinitiator P. The present invention also concerns the provision of a silicone composition that can be polymerized or crosslinked by free-radical process comprising a type II photoinitiator system suitable for crosslinking silicone compositions, in particular by exposure to radiation, and absorbing light radiation with a wavelength greater than 300 nm.

A 3D printing system includes a vat containing a liquid photopolymer resin and a rigid base on which an object is configured to be printed. A control arm connected to the rigid base is configured to move the rigid base relative to the vat. A first light source is configured to emit light to the vat to form the object on the rigid base. A second light source is configured to emit light on the object externally of the liquid photopolymer resin in the vat to cure the object.

A 3D printing system includes a vat containing a liquid photopolymer resin and a rigid base on which an object is configured to be printed. A control arm connected to the rigid base is configured to move the rigid base relative to the vat. A first light source is configured to emit light to the vat to form the object on the rigid base. A second light source is configured to emit light on the object externally of the liquid photopolymer resin in the vat to cure the object.

A profilometer provides, to a controller, a feedback signal indicative of topography of an exposed surface of an object that is being manufactured by a 3d printer. The profilometer includes an emitter and a camera. The emitter illuminates a region of surface of the object with a pattern having an edge that defines a boundary of an illuminated portion of the surface. The camera receives an image that transitions between a first state in which the edge is visible in the image at a location that is indicative of the surface's depth and a second state in which the edge is not visible at all. From this second state, the controller obtains information representative of a depth of the surface.

A profilometer provides, to a controller, a feedback signal indicative of topography of an exposed surface of an object that is being manufactured by a 3d printer. The profilometer includes an emitter and a camera. The emitter illuminates a region of surface of the object with a pattern having an edge that defines a boundary of an illuminated portion of the surface. The camera receives an image that transitions between a first state in which the edge is visible in the image at a location that is indicative of the surface's depth and a second state in which the edge is not visible at all. From this second state, the controller obtains information representative of a depth of the surface.

Apparatus (1) for manufacturing a three-dimensional object from a powder, the apparatus (1) comprising: a build bed (201) having a build area (190), wherein successive layers of said three-dimensional object are formed in the build bed (201); a powder distribution sled (300) operable to distribute a layer of powder within the build area (190), the powder distribution sled (300) being driveable in a first direction along a first axis, across the build area (190), and driveable in a second direction, opposite to the first direction, along the first axis; and a print sled (350) operable to deposit a pattern of fluid onto the layer of powder within the build area (190) to define the cross section of said object in said layer, the print sled (350) being driveable in the first direction along a second axis across the build area, and driveable in the second direction along the second axis; wherein the first axis is parallel to, or coaxial with, the second axis; wherein the print sled (350) comprises one or more droplet deposition heads (370) for depositing the fluid, a first radiation source assembly (L1), and a second radiation source assembly (L2); wherein the powder distribution sled (300) comprises a powder distribution device (320) for distributing the powder, a third radiation source assembly (L3) and a fourth radiation source assembly (L4); and wherein each of the first, second, third and fourth radiation source assemblies is operable to both preheat and sinter powder within the build area (190). A method of manufacturing a three-dimensional object from a powder using such apparatus is also provided.

Apparatus (1) for manufacturing a three-dimensional object from a powder, the apparatus (1) comprising: a build bed (201) having a build area (190), wherein successive layers of said three-dimensional object are formed in the build bed (201); a powder distribution sled (300) operable to distribute a layer of powder within the build area (190), the powder distribution sled (300) being driveable in a first direction along a first axis, across the build area (190), and driveable in a second direction, opposite to the first direction, along the first axis; and a print sled (350) operable to deposit a pattern of fluid onto the layer of powder within the build area (190) to define the cross section of said object in said layer, the print sled (350) being driveable in the first direction along a second axis across the build area, and driveable in the second direction along the second axis; wherein the first axis is parallel to, or coaxial with, the second axis; wherein the print sled (350) comprises one or more droplet deposition heads (370) for depositing the fluid, a first radiation source assembly (L1), and a second radiation source assembly (L2); wherein the powder distribution sled (300) comprises a powder distribution device (320) for distributing the powder, a third radiation source assembly (L3) and a fourth radiation source assembly (L4); and wherein each of the first, second, third and fourth radiation source assemblies is operable to both preheat and sinter powder within the build area (190). A method of manufacturing a three-dimensional object from a powder using such apparatus is also provided.