Abstract: A membrane electrode assembly includes a polyelectrolyte membrane having a first surface and a second surface facing away from the first surface; a fuel-electrode-side electrocatalyst layer bonded to the first surface and containing a first catalytic material, a first electrically conductive carrier, and a first polyelectrolyte, the first electrically conductive carrier carrying the first catalytic material; and an oxygen-electrode-side electrocatalyst layer bonded to the second surface and containing a second catalytic material, a second electrically conductive carrier, a second polyelectrolyte, and a fibrous material, the second electrically conductive carrier carrying the second catalytic material. The membrane electrode assembly contains voids, the voids including pores each having a size in a range of 3 nm or more and 5.5 ?m or less.

Abstract: A color developing structure that exhibits good color development and ensures a desired transmittance while diffusing reflected light in multiple directions. A color developing structure includes a concave-convex layer in which a first surface has a concave-convex structure, and a reflective layer formed on the first surface to extend along the concave-convex structure. A convex surface of the concave-convex structure has a first pattern composed of a plurality of strip portions in plan view. The strip portion has a width in a first direction and a length in a second direction perpendicular to the first direction. The width is smaller than the wavelength of the incident light, and a standard deviation of the lengths of the plurality of strip portions is larger than a standard deviation of the widths.

Abstract: An electrode catalyst layer includes a catalyst material, a conductive carrier, which supports the catalyst material, a polymer electrolyte, and a fibrous material. The electrode catalyst layer includes a three-dimensional network of a flow path. The flow path includes a plurality of terminal points and a plurality of branches. Each of the branches is an elongated hole connecting a pair of the terminal points. The plurality of branches include a bifurcated branch. One of the pair of the terminal points of the bifurcated branch is connected to another branch. The number of branches per unit volume of the electrode catalyst layer is 8500 or more and 13000 or less. The unit volume is defined as 3.9 ?m×3.9 ?m×4.4 ?m.

Abstract: A membrane electrode assembly includes a polyelectrolyte membrane having a first surface and a second surface facing away from the first surface; a fuel-electrode-side electrocatalyst layer bonded to the first surface and containing a first catalytic material, a first electrically conductive carrier, and a first polyelectrolyte, the first electrically conductive carrier carrying the first catalytic material; and an oxygen-electrode-side electrocatalyst layer bonded to the second surface and containing a second catalytic material, a second electrically conductive carrier, a second polyelectrolyte, and a fibrous material, the second electrically conductive carrier carrying the second catalytic material. The membrane electrode assembly contains voids, the voids including pores each having a size in a range of 3 nm or more and 5.5 ?m or less.

Abstract: A color developing structure that exhibits good color development and ensures a desired transmittance while diffusing reflected light in multiple directions. A color developing structure includes a concave-convex layer in which a first surface has a concave-convex structure, and a reflective layer formed on the first surface to extend along the concave-convex structure. A convex surface of the concave-convex structure has a first pattern composed of a plurality of strip portions in plan view. The strip portion has a width in a first direction and a length in a second direction perpendicular to the first direction. The width is smaller than the wavelength of the incident light, and a standard deviation of the lengths of the plurality of strip portions is larger than a standard deviation of the widths.