Progress in Strain Engineering of 2D-Integrated Heterostructures for Ultrasensitive Sensors

Two-dimensional (2D) integrated heterostructures have emerged as a cornerstone in the advancement of next-generation sensor technologies. These heterostructures, which combine materials with different dimensionalities, have led to significant breakthroughs in sensing performance and device integration. Owing to their tunable bandgaps and exceptional mechanical flexibility, the application of strain engineering in 2D-integrated heterostructures represents a dynamic and rapidly evolving research frontier. This review presents a comprehensive assessment of the current progress in strain engineering applied to 2D-integrated heterostructures. The review outlines the fundamental principles and distinctive properties exhibited in 2D-integrated heterostructures under applied strain. State-of-the-art 2D integration strategies and strain-induction techniques are then examined, followed by an in-depth analysis of key sensing mechanisms enabled by strain modulation. Recent advances in ultrasensitive sensing applications are highlighted, demonstrating the immense potential of strain-engineered 2D-integrated heterostructures. Finally, current challenges and outstanding bottlenecks are assessed, and future research directions are proposed, highlighting opportunities that may redefine the role of 2D-integrated heterostructures in next-generation sensing technologies.