Intrinsically stretchable and transparent conductors for next-generation soft optoelectronics [Invited]

The rapid advancement of optoelectronic devices has intensified the demand for materials that are not only functional but also mechanically adaptable to human-centric applications. Conventional transparent conductors, such as indium tin oxide, offer excellent conductivity and optical transparency but fail under mechanical strain, limiting their use in flexible and stretchable systems. This limitation has motivated the development of intrinsically stretchable and transparent conductors capable of maintaining electrical and optical performance under large, repeated deformations. These conductors are typically fabricated by embedding conducting fillers within elastomeric matrices, providing skin-like mechanical compliance without the need for complex geometric patterning and enabling seamless integration with soft, irregular surfaces. Intrinsically stretchable and transparent conductors can be divided into metallic and non-metallic conductors. Each category offers distinct advantages but also presents trade-offs among conductivity, transparency, stretchability, and environmental stability. Therefore, careful material selection and design optimization are essential to balance these competing properties. This review summarizes recent progress in intrinsically stretchable and transparent conductors, with a focus on materials and design strategies for optimizing electrical, optical, and mechanical performance. We further highlight their integration into optoelectronic devices and discuss remaining challenges and potential solutions to advance next-generation soft optoelectronic technologies.