Electroluminescence is the phenomenon where a material emits
light when electricity passes through it. It provides gentle, even
illumination for a material while consuming relatively little electric
power without producing heat.

Traditionally, it is used in automobile dashboards to illuminate car
meters, on small LCD panels, billboards, and backlights for liquid
crystal displays. Recently, it has been used for illuminating signage,
safety gear, bicycles, and costumes & apparel. Since it can be
applied to any shape, material, and can take on any color, the
possibilities are endless!