The disclosure relates to a hydrogen sensing device capable of visually detecting the presence of hydrogen through a color change according to a water-forming reaction by inducing the water-forming reaction between hydrogen and oxygen at the interface between a lower metal layer and a dielectric layer under a structure in which a lower metal layer, a dielectric layer, and an upper metal layer are sequentially stacked, and visually sensing the color change caused by the generated water.

The disclosed technology generally relates to preparing two-dimensional material layers, and more particularly to releasing a graphene layer from a template substrate. According to an aspect, a method of releasing a graphene layer includes providing a template substrate on which the graphene layer is provided, the method comprising: subjecting the graphene layer and the template substrate to a water treatment by soaking the graphene layer and the template substrate in water such that water is intercalated between the template substrate and the graphene layer; and subjecting the graphene layer and the template substrate to a delamination process, thereby releasing the graphene layer from the template substrate.

Systems, methods, and devices of the various embodiments provide for the creation of holey graphene meshes (HGMs) and composite articles including HGMs. Various embodiments provide solvent-free methods for creating arrays of holes on holey graphene-based articles formed from dry compression (such as films, discs, pellets), thereby resulting in a HGM. In further embodiments, a HGM can used as part of a composite, such as by: 1) embedding a HGM into another matrix material such as carbon, polymer, metals, metal oxides, etc; and/or (2) the HGM serving as a matrix by filling the holes of the HGM or functionalizing the HGM body with another one or more materials. In various embodiments, HGM can also be made as a composite itself by creating holes on dry-compressed articles pre-embedded with one or more other materials.

A membrane electrode assembly is provided that includes a polymer electrolyte membrane and a catalyst layer provided on a surface of the polymer electrolyte membrane. The catalyst layer comprises catalyst particles and an ionomer film surrounding each of the catalyst particles. The ionomer film has an oxygen permeability of approximately 6.010.sup.12 mol/cm/s to 15.010.sup.12 mol/cm/s at 80 C. and a relative humidity of approximately 30% to 100%.

The disclosed technology generally relates to preparing two-dimensional material layers, and more particularly to releasing a graphene layer from a template substrate. According to an aspect, a method of releasing a graphene layer includes providing a template substrate on which the graphene layer is provided, the method comprising: subjecting the graphene layer and the template substrate to a water treatment by soaking the graphene layer and the template substrate in water such that water is intercalated between the template substrate and the graphene layer; and subjecting the graphene layer and the template substrate to a delamination process, thereby releasing the graphene layer from the template substrate.

A laser beam irradiation unit of a laser processing apparatus includes a laser oscillator that oscillates a laser, a Y-axis scanner that executes a high-speed scan with a laser beam emitted from the laser oscillator in a Y-axis direction, an X-axis scanner that executes processing feed of the laser beam emitted from the laser oscillator in an X-axis direction, and a beam condenser. The Y-axis scanner is selected from any of an AOD, a resonant scanner, and a polygon scanner and the X-axis scanner is selected from a galvano scanner and a resonant scanner.

The disclosure relates to a hydrogen sensing device capable of visually detecting the presence of hydrogen through a color change according to a water-forming reaction by inducing the water-forming reaction between hydrogen and oxygen at the interface between a lower metal layer and a dielectric layer under a structure in which a lower metal layer, a dielectric layer, and an upper metal layer are sequentially stacked, and visually sensing the color change caused by the generated water.