Opening a bandgap in bilayer graphene typically requires either structural modification or continuous external electric fields, while twisted bilayer graphene configurations remain largely gapless without additional perturbation. Here, we demonstrate bandgap opening of up to 50 meV in structurally intact bilayer graphene by in-plane strain fields imposed by an interfaced porous organic 2D crystal. These sandwich graphene/organic 2D crystal/graphene (G-O2DC-G) heterostructures, with O2DCs of hone