Abstract: A fiber with which a further enhanced electric field intensity is obtained when a compressive force is applied across the longitudinal axis of the fiber. The fiber is composed of a potential generating filament having at least one interior angle of less than 120° in a contour shape in a sectional view in a direction perpendicular to a longitudinal axis of the fiber.

Abstract: A knitted fabric structure that includes a piezoelectric yarn having a piezoelectric material that produces a surface potential by input of an external force from an outside of the piezoelectric yarn; and an elastic yarn having stretchability knitted together with the piezoelectric yarn, wherein the piezoelectric yarn has a mixing ratio of 5% or more based on a whole of the knitted fabric structure.

Abstract: A fabric that includes a loop of a yarn including a voltage generating filament. The fabric has a value of X of 1,000 or more, where X=(A+B)×C×D×E, and wherein: A is a loop angle of the loop of the yarn when the fabric is stretched by 10%, B is a connection angle of the loop of the yarn when the fabric is stretched by 10%, C is a number of the loops of the yarn per 1 cm2 of the fabric, D is a force (N) applied per basis weight (g/m2) of the fabric, and E is a surface potential (V) of the yarn.

Abstract: A mask that exhibits a more improved antibacterial effect by more efficiently expanding and contracting a body of the mask in the periphery of the nose and mouth area of the mask without using a drug such as an antibacterial agent and/or an antiviral agent. The mask includes: a body including a yarn having a potential generating filament; and at least one dart that extends from an edge portion of the body towards a central portion of the body.

Abstract: A mask for covering at least a nostril and a mouth of a wearer. The mask includes a main body portion and an ear hooking portion attached to the main body portion. At least a part of the main body portion has a sheet-like piezoelectric portion, and the piezoelectric portion includes a yarn formed of an electric field forming filament.

Abstract: A cylindrical structure including a first cloth including a piezoelectric thread that generates an electric potential from external energy, a second cloth including a piezoelectric thread that generates an electric potential from external energy, and a connection portion connecting the first cloth and the second cloth, wherein the first cloth and the second cloth forms a side face of the cylindrical structure.