After removing the top PMMA layer along the edges of the substrate, the sacrificial PVA layer was dis-solved by applying a small amount of water to the rim of the film, which was quickly dragged into the film/substrate interfacial region (Figure , Steps 4 and 5). By gently pressing the PDMS stamp against the substrate, the hybrid film detached from the substrate and was transferred onto the stamp (Figure , Steps 6 and 7). By pressing the stamp against the target substrate, the hybrid film was transferred and freestanding membranes were obtained spanning the cavities or through hole of the substrate (Figure , Step 8). When removing the stamp, the hybrid film must detach from the stamp. This was achieved by applying three heating and cooling cycles (Figure , Step 9). Since the thermal expansion coefficients of the PDMS and the substrate-supported PMMA-protected hybrid film differ, the adhesion between the PDMS and PMMA was released, allowing the stamp to be removed from the hybrid film (Figure ,