Intrinsically Stretchable Light Emitting Devices: Toward Flexible, Foldable, and Bio‐Integrated Systems

Intrinsically stretchable light‐emitting devices have emerged as a foundational technology for next‐generation displays, conformal lighting, and bio‐integrated optoelectronics. Unlike structurally engineered stretchable architectures that depend on geometric strain management, intrinsic approaches embed elasticity directly into the functional materials, enabling uniform electroluminescence under large mechanical deformation without compromising spatial resolution or optical performance. This review provides a comprehensive study of recent advances in intrinsically stretchable electroluminescent materials, electrodes, charge‐transport layers, and high‐permittivity or ionogel dielectrics that enable strain‐independent charge injection and field distribution. Fabrication methodologies—from solution processing and printing to soft lamination and elastomeric encapsulation—are discussed with an emphasis on scalability, interfacial stability, and integration into monolithic stretchable devices. Applications in wearable displays, textile‐integrated illumination, conformal indicators, and skin‐mounted biomedical platforms are highlighted, demonstrating the field's transition from laboratory prototypes to functional, deformable systems suitable for real‐world use. Finally, we outline the main challenges, including morphological instability under cyclic strain, efficiency loss, interfacial degradation, and limited environmental durability, and identify opportunities in molecular design, supramolecular reinforcement, soft encapsulation, and additive manufacturing. Together, these developments position intrinsically stretchable light‐emitting technologies as a critical pathway toward flexible, foldable, and bio‐integrated optoelectronics.