Strain engineering in van der Waals materials towards flexible electronics and optoelectronics

Flexible electronics and optoelectronics are rapidly advancing toward multifunctional integration, high sensitivity, and low power consumption, enabling next-generation technologies in wearable sensing, energy harvesting, and intelligent systems. Van der Waals (vdW) materials, with their exceptional mechanical flexibility and tunable electronic and exceptional optoelectronic properties, form a promising foundation for flexible platforms, particularly when enhanced through strain engineering. While existing reviews have thoroughly explored property modulation in vdW materials, the complex relationship between these modulated properties and the resulting device performance has yet to be fully examined. This review presents a comprehensive analysis that unifies these interrelated elements, including strain application strategies, modulation of physical properties, and device-level implementation, into a cohesive framework for the design and optimization of high-performance flexible vdW electronic and optoelectronic systems. Finally, we summarize the key challenges and outline practical strategies to support the development of next-generation flexible vdW applications that seamlessly integrate multimodal sensing, memorizing, and computing, thereby enabling intelligent, adaptive, and scalable system architectures. • Novel strain application strategies in van der Waals materials were summarized • A unified cohesive framework, integrating strain engineering techniques, property modulation, and device performance optimization was established • The critical role and unique advantages of strain engineering in advancing next-generation flexible vdW electronics and optoelectronics were elucidated • Key challenges hindering future progress were identified, and feasible solutions were proposed