Intrinsically soft electronics using conducting nanomaterials and liquid metals

Abstract Flexible electronics have significantly influenced modern daily life, particularly in personalized, human-centric applications, due to their ability to conform to curved surfaces. Building on this adaptability, researchers are now focusing on developing stretchable electronic devices that promise next-generation form factors, offering unprecedented user experience and functionalities. Current approaches employ rigid electronic materials configured in strain-accommodating geometries, achieving a high level of technological maturity by leveraging well-established technologies. However, these strategies face limitations, particularly in terms of long-term durability under repeated deformation, primarily due to their reliance on non-stretchable components. To overcome these limitations and facilitate durable deformation, intrinsically stretchable electronic materials have emerged as a promising solution. This review highlights recent advancements in intrinsically soft electronics, with a particular focus on stretchable conductors based on metallic components. Key elements of intrinsically stretchable conductors are discussed, including elastomers used as stretchable substrates, and metallic ingredients such as low-dimensional metallic nanomaterials and liquid metals. Additionally, we explore various assembly and patterning techniques for these materials. Practical applications of metal-based intrinsically soft conductors are highlighted, and this review concludes with an outlook on the prospects and potential challenges for these emerging technologies.