Researchers have discovered a general strategy for activating ferroelectricity in bilayer 2D materials using intercalating inert atoms. This breakthrough has led to various findings, including the emergence of ferroelectricity in nonferroelectric monolayers and the creation of ferroelectric metals with unique properties. The research has also explored the potential applications of ferroelectricity in 2D materials, such as tunnel junctions and multiresistance states.