Colorimetric and self-sealing photonic crystal film for early detection of SF₆ leakage in gas-insulated equipment

Sulfur hexafluoride (SF6), widely used in gas-insulated switchgear (GIS), is a potent greenhouse gas with high global warming potential, making leakage reduction a critical challenge for the power industry. In practice, SF6 leaks often occur at structural interfaces and are difficult to detect early using conventional pressure-based or manual inspection methods, leading to delayed response and increased environmental impact. To address this issue, this paper proposes a flexible colorimetric photonic crystal film for early and location-specific SF6 leak detection. The film can be directly applied to leakage-prone areas and enables passive visualization of leaks. Escaping gas induces mechanical deformation of the film, causing a reversible structural color change due to the shift of the…