Abstract: An apparatus and method for microcontact printing are described. The microcontact printing apparatus includes a planar stamp and a pressurized roller. The pressurized roller includes an inflatable bladder that can be inflated by a fluid to a pressure that reduces printing defects such as voids and stamp collapse. A substrate is disposed between the pressurized roller and a stamp coated with an ink of functionalizing molecules. As the pressurized roller moves over the substrate, at least a portion of the functionalizing molecules are transferred from the stamp to the substrate in the desired pattern.

Abstract: The present disclosure relates to prismatic retroreflective articles that includes a security mark and to methods of making such articles.

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: An apparatus and a method for micro-contact printing on a substrate. A roll having very low drag is supported for rotation by air bearings and has a micro-contact printing stamp mounted to its outer surface. Contact between the substrate and the micro-contact printing stamp drives the roll and repeatedly imprints the pattern onto the web. In convenient embodiments, the roll is a sleeve positioned over a core with the sleeve supported for rotation by a layer of air between the sleeve and the core.

Abstract: The present disclosure describes an article and a method of forming a microstructure. The method includes providing a substrate having a structured surface region comprising one or more recessed features with recessed surfaces. The structured surface region is substantially free of plateaus. The method includes disposing a fluid composition comprising a functional material and a liquid onto the structured surface region. The method includes evaporating liquid from the fluid composition. The functional material collects on the recessed surfaces such that a remainder of the structured surface region is substantially free of the functional material.

Abstract: A method of preparing a patterned micro-contact printing stamp for micro contact printing including the making of a submaster of e.g. epoxy, against which a micro-contact printing stamp from polydimethylsiloxane or other stamp forming material can be formed. The micro-contact printing stamp can then be exposed to an inking material while the micro-contact printing stamp is still against the submaster, resulting in a micro-contact printing stamp capable of making numerous impressions before the inking material is exhausted.

Abstract: The present disclosure describes an article and a method of forming a microstructure. The method includes providing a substrate having a structured surface region comprising one or more recessed features with recessed surfaces. The structured surface region is substantially free of plateaus. The method includes disposing a fluid composition comprising a functional material and a liquid onto the structured surface region. The method includes evaporating liquid from the fluid composition. The functional material collects on the recessed surfaces such that a remainder of the structured surface region is substantially free of the functional material.

Abstract: An apparatus and a method for micro-contact printing on a substrate. A roll having very low drag is supported for rotation by air bearings and has a micro-contact printing stamp mounted to its outer surface. Contact between the substrate and the micro-contact printing stamp drives the roll and repeatedly imprints the pattern onto the web. In convenient embodiments, the roll is a sleeve positioned over a core with the sleeve supported for rotation by a layer of air between the sleeve and the core.

Abstract: This application describes a back-lit transmissive display including a transmissive display (620) and a variable index light extraction layer (640) optically coupled to a lightguide (630). The variable index light extraction layer has first regions (140) of nanovoided polymeric material and second regions (130) of the nanovoided polymeric material and an additional material. The first and second regions are disposed such that for light being transported at a supercritical angle in the lightguide, the variable index light extraction layer selectively extracts the light in a predetermined way based on the geometric arrangement of the first and second regions. The transmissive display may be a transmissive display panel or a polymeric film such as a graphic.

Abstract: A method of forming a patterned substrate is provided. The method includes providing a substrate (300) having a structured surface region comprising one or more recessed features (310). The method includes disposing a first liquid (325) onto at least a portion of the structured surface region. The method includes contacting the first liquid with a second liquid (330). The method includes displacing the first liquid with the second liquid from at least a portion (315) of the structured surface region. The first liquid is selectively located in at least a portion of the one or more recessed features.

Abstract: Methods of altering charge on a dielectric material involve application of an at least weakly conductive liquid to at least a portion of the dielectric material. The liquid is then at least partially removed from the dielectric material leaving a substantially uniform electrostatic charge on at least the portion of the dielectric material. Some methods provide a dielectric material that is both net neutral and completely neutral. Other methods generate a charge pattern that is used for subsequent processing.

Abstract: An article having a first major surface with at least first and second regions, the first region comprising a plurality of first structures having a first surface roughness, the second region comprising a plurality of second structures having a second surface roughness, wherein at least a portion of the at least first and second regions have a surface roughness difference between them that together exhibit at least a portion of a first image. Exemplary uses of the articles include tool-less macro-patterning of transflectors, customized appearance for retroreflective sheeting, incorporation of security features, decorative patterns for lighting diffusers, images or logos in medical films without inks or contamination.

Abstract: A method for coating a work piece with resin including applying a controlled volume of liquid resin to the work piece with an applicator and allowing consecutive streams of resin to meld together to form a self leveling surface. The resin can be actively or passively cured. The work piece can be planar or cylindrical.

Abstract: A method for coating a work piece with resin including applying a controlled volume of liquid resin to the work piece with an applicator and allowing consecutive streams of resin to meld together to form a self leveling surface. The resin can be actively or passively cured. The work piece can be planar or cylindrical.

Abstract: This disclosure generally relates to retroreflective articles and methods of making such articles.

Abstract: A method of producing substrates having a patterned mask layer with fine features such as repeating stripes. The method including the steps of forming a substrate having a transfer layer with a predetermined pattern on a first major surface of the substrate; providing the substrate having the transfer layer on the first major surface; providing a structured tool having a body and a plurality of contact portions, the contact portions having a Young's Modulus between about 0.5 Gpa to about 30 Gpa; heating either the structured tool or the substrate; contacting the transfer layer with the structured tool; cooling the transfer layer; and withdrawing the structured tool from the transfer layer such that portions of the transfer layer separate with the structured tool leaving openings in the transfer layer that extend all the way through the transfer layer to the substrate forming the transfer layer with the predetermined pattern.

Abstract: This disclosure generally relates to retroreflective articles and methods of making such articles.

Abstract: Surface-modified adhesives may be prepared by contacting an adhesive layer to an at least partially discontinuous layer on a releasing substrate and removing the adhesive layer such that at least a portion of the at least partially discontinuous layer adheres to the adhesive surface. The modified adhesive surface remains an adhesive surface. The modified adhesive layer can be used to prepare adhesive articles, including articles containing multiple surface-modified adhesive layers.

Abstract: An apparatus and method for microcontact printing are described. The microcontact printing apparatus includes a planar stamp and a pressurized roller. The pressurized roller includes an inflatable bladder that can be inflated by a fluid to a pressure that reduces printing defects such as voids and stamp collapse. A substrate is disposed between the pressurized roller and a stamp coated with an ink of functionalizing molecules. As the pressurized roller moves over the substrate, at least a portion of the functionalizing molecules are transferred from the stamp to the substrate in the desired pattern.

Abstract: Methods and systems for flexographic printing are described and include curing of material to be printed while the material is in contact with both a feature of a flexographic printing plate and a recipient substrate. The systems and method are useful in preventing slippage between the feature and the recipient substrate, and are particularly useful when printing at high resolution.