Abstract: Light guides comprising light extraction structure arrays and articles comprising such light guides are described.

Abstract: Compositions such as photoresists and microfabrication processes are provided that can produce high-fidelity microfabricated structures. The provided photoresists can have reduced swelling during the development phase and can give tight tolerances for products, such as microneedles, that can be used, for example, in the medical field. The provided compositions include a photoresist, a photoinitiator system dispersed in the photoresist, and a polymer-tethered nanoparticle dispersed in the photoresist. The photoresist can be a negative photoresist and the photoinitiator system can include a two-photoinitiator system. The polymer-tethered nanoparticle can include an acrylic polymer and, in some embodiments, can include poly(methyl methacrylate). The nanoparticles can include silica.

Abstract: A method of forming a working mold including: placing a substrate (610) on an electrode in a chamber, the substrate having at least a first structured surface (620) and the substrate including a thermoset polymeric material; introducing a release (630) layer forming gas into the chamber, wherein the release layer forming gas includes silicon containing gas and oxygen gas in an atomic ratio of not greater than about 200; providing power to the electrode to create a plasma of the release layer forming gas within the chamber; and depositing a release layer formed from the release layer forming gas on at least the first structured surface of the substrate to form a working mold.

Abstract: Novel benzoxazine-thiol adducts are described, which may be may be cured to produce compositions useful in coating, sealants, adhesive and many other applications.

Abstract: The present disclosure relates to multiphoton absorption methods for curing a photocurable composition under conditions wherein negative contrast occurs. The photocurable composition includes a free-radically polymerizable compound. The method is applicable to fabrication of structures with micron-scale dimensions or less.

Abstract: An exposure system includes a light source emitting a beam along an optical axis that is capable of inducing a multi-photon reaction in a resin. The exposure system further includes a resin undergoing multiphoton reaction, as well as an automated system including a monitor that measures at least one property of the beam selected from power, pulse length, shape, divergence, or position in a plane normal to the optical axis. The monitor generates at least one signal indicative of the property of the beam, and a sub-system adjusts the beam in response to the signal from the monitor.

Abstract: A process for making a microneedle array master comprises: (a) providing a photoreactive composition, the photoreactive composition comprising: (1) at least one reactive species that is capable of undergoing an acid- or radical-initiated chemical reaction, and (2) at least one multiphoton photoinitiator system; and (b) imagewise exposing at least a portion of the composition to light sufficient to cause simultaneous absorption of at least two photons, thereby inducing at least one acid- or radical-initiated chemical reaction where the composition is exposed to the light, the imagewise exposing being carried out in a pattern that is effective to define at least the surface of a plurality of microneedles. The microneedles may be solid and the outer surface of the microneedles may be characterized by at least one concave area. The master may be used to fabricate a tool for replication.

Abstract: A method for building three-dimensional articles using a thermal polymerization process in provided. The articles are built by using a composition that includes a thermally polymerizable composition, a thermal initiator, and a nonlinear light-to-heat conversion material such as a reverse saturable dye. The article is built by the sequential exposure of adjacent voxels with a laser beam. Microlens arrays can be used to expose more than one voxel at a time.

Abstract: An exposure system includes a light source emitting a beam along an optical axis that is capable of inducing a multi-photon reaction in a resin. The exposure system further includes a resin undergoing multiphoton reaction, as well as an automated system including a monitor that measures at least one property of the beam selected from power, pulse length, shape, divergence, or position in a plane normal to the optical axis. The monitor generates at least one signal indicative of the property of the beam, and a sub-system adjusts the beam in response to the signal from the monitor.

Abstract: Compositions such as photoresists and microfabrication processes are provided that can produce high-fidelity microfabricated structures. The provided photoresists can have reduced swelling during the development phase and can give tight tolerances for products, such as microneedles, that can be used, for example, in the medical field. The provided compositions include a photoresist, a photoinitiator system dispersed in the photoresist, and a polymer-tethered nanoparticle dispersed in the photoresist. The photoresist can be a negative photoresist and the photoinitiator system can include a two-photoinitiator system. The polymer-tethered nanoparticle can include an acrylic polymer and, in some embodiments, can include poly(methyl methacrylate). The nanoparticles can include silica.

Abstract: A method and a multi-photon photocurable composition are provided that allow for the formation of a three-dimensional microstructure having enhanced imaging resolution. The method involves providing a multi-photon photocurable composition system having an acrylic prepolymer and a multiphotohn photoinitiator system that comprises at least one distyrylbenzene dye or a benzothiazolyl fluorine derivative. The method includes imagewise exposing at least one voxel of the photocurable composition to a dose of electromagnetic energy under conditions effective to photodefinably form at least one solid voxel of a three-dimensional microstructure having a volume, wherein the solid voxel volume varies inversely with the dose.

Abstract: An exposure system includes a light source emitting a beam along an optical axis that is capable of inducing a multi-photon reaction in a resin. The exposure system further includes a resin undergoing multiphoton reaction, as well as an automated system including a monitor that measures at least one property of the beam selected from power, pulse length, shape, divergence, or position in a plane normal to the optical axis. The monitor generates at least one signal indicative of the property of the beam, and a sub-system adjusts the beam in response to the signal from the monitor.

Abstract: Nozzle and a method of making the same are disclosed.

Abstract: Methods of fabricating optical elements that are encapsulated in monolithic matrices. The present invention is based, at least in one aspect, upon the concept of using multiphoton, multi-step photocuring to fabricate encapsulated optical element(s) within a body of a photopolymerizable composition. Imagewise, multiphoton polymerization techniques are used to form the optical element. The body surrounding the optical element is also photohardened by blanket irradiation and/or thermal curing to help form an encapsulating structure. In addition, the composition also incorporates one or more other, non-diffusing binder components that may be thermosetting or thermoplastic. The end result is an encapsulated structure with good hardness, durability, dimensional stability, resilience, and toughness.

Abstract: Disclosed are surfaces for resisting and reducing biofilm formation, particularly on medical articles (100). The surfaces include a plurality of microstructures (120) including a plurality of nanofeatures (140) arranged according to at least one unit cell. Also disclosed are methods for creating anti-adherent surfaces.

Abstract: A method includes scanning a radiation beam with respect to a multi-photon curable photoreactive composition. The radiation beam includes a power sufficient to at least partially cure a volume of the multiphoton curable photoreactive composition. The method further includes modifying a characteristic of the radiation beam as the radiation beam is scanned.

Abstract: Novel benzoxazine-thiol adducts are described, which may be may be cured to produce compositions useful in coating, sealants, adhesive and many other applications.

Abstract: Novel benzoxazine-thiol adducts are described, which may be may be cured to produce compositions useful in coating, sealants, adhesive and many other applications.

Abstract: A method for forming a color shifting film on a support, the film comprising a reflective stack disposed adjacent to the support and an image is disclosed. The reflective stack comprises an at least partially transparent spacer layer comprising a substituted acrylamide polymer disposed between a partially reflective first layer and a reflective second layer. The acrylamide layer has a thickness sufficient to produce an interference color.

Abstract: A process for making a microlens array or a microlens array masterform comprises (a) providing a photoreactive composition, the photoreactive composition comprising (1) at least one reactive species that is capable of undergoing an acid- or radical-initiated chemical reaction, and (2) at least one multiphoton photoinitiator system; and (b) imagewise exposing at least a portion of the composition to light sufficient to cause simultaneous absorption of at least two photons, thereby inducing at least one acid- or radical-initiated chemical reaction where the composition is exposed to the light, the imagewise exposing being carried out in a pattern that is effective to define at least the surface of a plurality of microlenses, each of the microlenses having a principal axis and a focal length, and at least one of the microlenses being an aspherical microlens.