Abstract: A retroreflective sign comprising a rigid substrate with a pattern of cell walls formed of a polyurethane adhesive or two-part polyurea adhesive, and a polymeric sheet having a front face and a rear face, the rear face facing the substrate, the rear face comprising microprismatic reflective elements is disclosed. The polymeric sheet is adhered directly to the cell walls formed of the polyurethane adhesive or two-part polyurea adhesive while leaving an air gap between the microprismatic retroreflective elements and the rigid substrate in the cells. A method of making the retroreflective sign includes applying a polyurethane adhesive or two-part polyurea adhesive to a front side of a rigid substrate in a pattern defining cell walls; and prior to full curing of the polyurethane adhesive, laminating the front side of the rigid substrate a rear side of a polymeric sheet via the cell walls, the polymeric sheet comprising microprismatic elements.

Abstract: In an embodiment, a molding apparatus for a turbine blade includes first and second mold compartments defining a mold cavity when in a closed position, at least one of the first and second mold compartments including a micro-structured surface facing an interior of the mold cavity. The micro-structured surface includes an array of V-shaped channels, and the V-shaped channels have a maximum height of 200 micrometers. A turbine blade including integral micro-structured riblets and method for making the turbine blade is also provided.

Abstract: A novel array of hollow silica glass microneedles is provided. The array is prepared from a silica dispersion. A novel apparatus is provided comprising a negative mold component having tapered openings therein and a positive mold component having positive elements that are received within the tapered openings of the negative mold component. An assembly is prepared of the negative mold component and the positive mold component, with an aqueous silica dispersion received within the space between the outer surface of the positive elements and the inner surface of the openings. The assembly is heated to remove air and water vapors from the silica dispersion, then the assembly is further heated to sinter the remaining silica to silica glass. The sintered silica glass when removed from the mold components is in the form of an array of microneedles.

Abstract: The apparatus comprises a mold assembly including at least one bore therethrough having a cavity therein defining the shape of the finished microneedle shape to be formed therein. The bore has an inlet opening and an exit opening. The apparatus also comprises means for locating the polymer to be formed at one end of the cavity and means for introducing fluid into the inlet opening of said bore and into the cavity. The apparatus also comprises exhaust means communicating with the exit opening of the bore, so that introducing the fluid through the polymer causes the polymer to assume the shape of the cavity and the fluid forms a hollow channel to define a needle-like structure in the polymer as the fluid is exhausted through the cavity and the bore.

Abstract: There is disclosed a method and apparatus for producing a polymeric film that accurately replicates a complex mold surface at least a portion of which surface has microstructured or nano-structured dimensions. A polymeric powder is electrodeposited on an underlying mold surface. Then the powder is cured to create a polymeric film. Finally the film is removed from the mold surface.

Abstract: There is disclosed a method and apparatus for producing a polymeric film that accurately replicates a mold surface at least a portion of which surface has a complex pattern of microstructured or nano-structured dimensions. A polymeric powder is electrodeposited on an underlying mold surface and heated to its molten state to replicate a pattern on the mold surface. Then the powder can be cured to create a polymeric film. Finally the film is removed from the mold surface.

Abstract: There is disclosed a method and apparatus for producing a polymeric film that accurately replicates a complex mold surface at least a portion of which surface has microstructured or nano-structured dimensions. A polymeric powder is electrodeposited on an underlying mold surface. Then the powder is cured to create a polymeric film. Finally the film is removed from the mold surface.

Abstract: The apparatus comprises a mold assembly including at least one bore therethrough having a cavity therein defining the shape of the finished microneedle shape to be formed therein. The bore has an inlet opening and an exit opening. The apparatus also comprises means for locating the polymer to be formed at one end of the cavity and means for introducing fluid into the inlet opening of said bore and into the cavity. The apparatus also comprises exhaust means communicating with the exit opening of the bore, so that introducing the fluid through the polymer causes the polymer to assume the shape of the cavity and the fluid forms a hollow channel to define a needle-like structure in the polymer as the fluid is exhausted through the cavity and the bore.

Abstract: The apparatus comprises a mold assembly including at least one bore therethrough having a cavity therein defining the shape of the finished microneedle shape to be formed therein. The bore has an inlet opening and an exit opening. The apparatus also comprises means for locating the polymer to be formed at one end of the cavity and means for introducing fluid into the inlet opening of said bore and into the cavity. The apparatus also comprises exhaust means communicating with the exit opening of the bore, so that introducing the fluid through the polymer causes the polymer to assume the shape of the cavity and the fluid forms a hollow channel to define a needle-like structure in the polymer as the fluid is exhausted through the cavity and the bore.