Nanoscale engineering of non-uniform biaxially strained domes

Strain engineering in two-dimensional (2D) materials enables control over topological states, carrier behaviour, and bandgap properties, opening new functionalities for nanodevices. A core need toward advanced applications is stable, atomically thin 2D structures which sustain large strains. Among various strained architectures, nanoscale non-uniform biaxially strained domes, which form when either gases, liquids, or contaminants are trapped beneath 2D crystals are a promising candidate. Domes manifest due to the interplay between elasticity, trapped matter, and van der Waals forces. This review summarises dome fabrication strategies, including top-down and bottom-up approaches, highlighting proton irradiation as a promising route for spatially patterned, highly pressurised domes with varying geometry and well-defined strain profiles. Domes exhibit constant height-to-radius ratios and stable strain profiles and serve as platforms for probing pseudomagnetic fields, exciton transport, adhesion mechanics, etc. Large non-uniform biaxial strain makes 2D domes promising candidates for next-generation nanodevices, which exhibit advanced material properties.