Abstract: A polymer bilayer includes a layer of a porous fluoropolymer directly overlying a layer of polyethylene. The polyethylene layer may be porous or dense and may include an ultra-high molecular weight polymer. The polymer bilayer may be co-integrated with structures (e.g., wearable devices) exposed to high thermal loads (>0-1000 W/m2) and provide passive cooling thereof. For instance, passive cooling of AR/VR glasses under different solar loads may be achieved by a polymer bilayer that is both highly reflective across solar heating wavelengths and highly emissive in the long-wavelength infrared. The high reflectance decreases energy absorption across the solar spectrum while the high emissivity promotes radiative heat transfer to the surroundings.

Abstract: A varifocal lens includes a substrate having an inclined region, a primary electrode disposed over the inclined region of the substrate, a dielectric layer disposed over the primary electrode, a deformable membrane disposed over and at least partially spaced away from the dielectric layer, a secondary electrode disposed over a surface of the deformable membrane facing toward or away from the dielectric layer and overlying at least a portion of the primary electrode, and a fluid between the membrane and the substrate, wherein a surface of the dielectric layer facing the secondary electrode comprises a textured surface.

Abstract: A liquid dispersion includes a matrix phase of polymerizable material and at least 10% by volume of solid conductive particles distributed throughout the matrix. The conductive particles may have an average particle size of less than approximately 100 nm, and the liquid dispersion may have a viscosity of less than approximately 100 Poise. Such a liquid dispersion may be printed or extruded and then cured to form a solid thin film. The content and distribution of conductive particles within the thin film may reach a percolation threshold such that the thin film may form a conductive layer. Polymer-based devices, such as nanovoided polymer (NVP)-based actuators may be formed by co-extrusion of a nanovoided polymer material between conductive polymer electrodes.

Abstract: An example apparatus may include a display and an optical configuration configured to provide an image of a display, for example, in a head-mounted device. The optical configuration may include a Fresnel lens assembly including a Fresnel lens and a reflective polarizer. The Fresnel lens may have a structured surface including a plurality of facets, and there may be a step between pairs of neighboring facets. The reflective polarizer may include a plurality of reflective polarizer portions, where each reflective polarizer portion conforms to a corresponding facet of the Fresnel lens. The reflective polarizer may be configured to reflect a first polarization and transmit a second polarization of incident light. The optical configuration may form an image of the display viewable by a user when the user wears the apparatus. Other devices, methods, systems, and computer-readable media are also disclosed.

Abstract: A polymer laminate includes a plurality of ultra-high molecular weight polyethylene thin films, where each polyethylene thin film has an in-plane thermal conductivity of at least approximately 5 W/mK and an in-plane elastic modulus of at least approximately 20 GPa. The polymer laminate may be incorporated into an eyewear device and may be configured to disperse heat during operation thereof in a manner effective to improve the functionality and/or wearability of the device.

Abstract: An optical film includes a plurality of helically arranged liquid crystals and organic solid crystal structures at least partially surrounding the plurality of helically arranged liquid crystals. A method of making the optical film includes obtaining a substrate with an alignment layer and a film of a first solution on the alignment layer. The first solution includes liquid crystals and organic crystal molecules. The liquid crystals form a plurality of helically arranged liquid crystals on the alignment layer. The method also includes forming organic solid crystal structures by crystallizing the organic crystal molecules. The organic solid crystal structures at least partially surround the plurality of helically arranged liquid crystals.

Abstract: An optical film includes a block copolymer film defining a plurality of helically shaped cavities and a plurality of helically shaped organic solid crystals positioned within the plurality of helically shaped cavities. A method of making the optical film includes obtaining a film of a block copolymer solution including a chiral block copolymer and a non-chiral block copolymer on a substrate. The method includes annealing the film, thereby forming a plurality of helical structures from the chiral block copolymer defined within the non-chiral block copolymer and removing the plurality of helical structures, thereby creating a plurality of helically shaped cavities. The method further includes forming organic solid crystals inside the plurality of helically shaped cavities, thereby forming the optical film.

Abstract: Methods of bonding together substrates that do not require use of primers, mixing, fixturing, or autoclaving. These methods can include the steps of disposing an adhesive layer on a bonding surface of either substrate, the adhesive layer comprising a curable composition that is dimensionally stable at ambient conditions; either before or after disposing the adhesive layer on the bonding surface, irradiating the adhesive layer with ultraviolet radiation to initiate curing of the curable composition; placing one substrate so as to be bonded to the other substrate by the adhesive layer; and allowing the adhesive layer to cure.

Abstract: Mechanically and piezoelectrically anisotropic polymer fibers may be formed by spinning a polymer solution or gel that includes a high molecular weight crystallizable polymer and a liquid solvent. The solvent may be configured to interact with the polymer to facilitate chain alignment and, in some examples, create a higher crystalline content within the spun fibers. The polymer solution may also include a low molecular weight additive. The high and low molecular weight polymers may each be characterized by a bimodal molecular weight distribution where the molecular weight of the additive is less than the molecular weight of the crystallizable polymer. The polymer(s) and the additive(s) may be independently selected from vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, hexafluoropropene, vinyl fluoride, etc. The spun fibers may be oriented, annealed, poled, and woven or laminated to form a polymer thin film having a high elastic modulus and a high electromechanical coupling factor.

Abstract: Disclosed is a polymeric waveguide for propagating light therein along width and length dimensions of the polymeric waveguide. The polymeric waveguide has a first curved surface on one side thereof and a second curved surface on an opposite second side thereof, and a refractive index spatially varying through a thickness thereof between the first curved surface and the second curved surface. The polymeric waveguide is curved in a cross-section comprising at least one of the width and length dimensions.

Abstract: An optically anisotropic polymer thin film includes a crystallizable polymer and an additive configured to interact with the polymer (e.g., via ?-? interactions) to facilitate chain alignment and, in some examples, create a higher crystalline content within the polymer thin film. The polymer thin film may be characterized by a bimodal molecular weight distribution where the molecular weight of the additive may be less than approximately 50% of the molecular weight of the crystallizable polymer. Example crystallizable polymers include polyethylene naphthalate, polyethylene terephthalate, polybutylene naphthalate, polybutylene terephthalate, as well as derivatives thereof. Example additives, which may occupy up to approximately 10 wt. % of the polymer thin film, include aromatic ester oligomers, aromatic amide oligomers, and polycyclic aromatic hydrocarbons, for example. The optically anisotropic polymer thin film may be characterized by a refractive index greater than approximately 1.

Abstract: A film stack includes a plurality of first films and a plurality of second films alternately stacked. At least one second film of the plurality of second films includes a solid crystal including crystal molecules aligned in a predetermined alignment direction. At least one first film of the plurality of first films includes an alignment structure configured to at least partially align the crystal molecules of the solid crystal in the predetermined alignment direction.

Abstract: A method includes applying a stress to a polymer thin film to stretch the polymer thin film along a first in-plane direction, and subsequently applying a stress to the polymer thin film to stretch the polymer thin film along a second in-plane direction orthogonal to the first in-plane direction to form an ultra-high modulus polymer thin film. Calendaring or hot pressing of the ultra-high modulus polymer thin film may improve its optical and/or thermal properties.

Abstract: A fluidic optical element includes a fluid bilayer having a first fluid layer and a second fluid layer defining a fluid interface therebetween, and an electrode disposed over a surface of the fluid bilayer. The geometry of the fluid interface and hence the optical response of the fluid bilayer to incident light may be manipulated using the principle of dielectrophoresis.

Abstract: A polymer multilayer includes two or more laminated layers of ultra-drawn, ultra-high molecular weight polyethylene or high density polyethylene. A transparent laminated structure may include such a polymer multilayer disposed between a pair of transparent substrates. The polymer multilayer may be configured to induce a compressive stress in a near surface region of each transparent substrate, which may improve the toughness and fracture resistance of the laminated structure. A photothermal dye may be incorporated into the polymer matrix and the compressive stresses may be achieved using photothermal actuation of the dye-containing polyethylene layers.

Abstract: A polymer layer includes a first in-plane refractive index extending along a first direction of the polymer layer, a second in-plane refractive index less than the first in-plane refractive index extending along a second direction of the polymer layer orthogonal to the first direction, a third refractive index along a direction orthogonal to both the first direction and the second direction, and a plurality of wrinkles extending along a surface of the polymer layer, where a difference between the first in-plane refractive index and the second in-plane refractive index is at least approximately 0.05, and the third refractive index is greater than the second in-plane refractive index.

Abstract: An example device may include a light source, an optical element, and, optionally, an encapsulant layer. A light beam generated by the light source may be received by the optical element and redirected towards an illumination target, such as an eye of a user. The optical element may include a material, for example, with a refractive index of at least approximately 2 at a wavelength of the light beam. The light source may be a semiconductor light source, such as a light-emitting diode or a laser. The optical element may be supported by an emissive surface of the light source. Refraction at an exit surface of the optical element, and/or within a metamaterial layer, may advantageously modify the beam properties, for example, in relation to illuminating a target. In some examples, the light source and optical element may be integrated into a monolithic light source module.

Abstract: IR drop predictions are obtained using a maximum convolutional neural network. A circuit structure is partitioned into a grid. For cells of the circuit structure in sub-intervals of a clock period, power consumption of the cell is amortized into a set of grid tiles that include portions of the cell, thus forming a set of power maps. The power maps are applied to a neural network to generate IR drop predictions for the circuit structure.

Abstract: An optical element is provided. The optical element includes a solid crystal including crystal molecules aligned in a predetermined alignment pattern at least partially defined by an alignment structure.

Abstract: This application discloses a data processing method and apparatus, a storage medium and an electronic device. The method includes: obtaining, by the electronic device, at least one target row to be cleared at a target time from a data table of a row-oriented database; storing target attribute values recorded in the at least one target row to target pages in a column-oriented database; and clearing the at least one target row after the target time arrives. The application resolves the technical problem that it is difficult to trace historical data in the related data processing technology.