Graphene-mediated blister-based laser-induced forward transfer of thin and ultra-thin ZrO₂

Blister-based laser-induced forward transfer (BB-LIFT) is a promising high precision and resolution printing technique for the fast, solvent- and mask-free transfer of functional layered materials onto micro-devices. It utilizes a protective metal (blister) layer sandwiched between the laser-transparent substrate and the material to be transferred. The metal layer absorbs the incident laser pulse, creating a rapidly expanding blister that propels the overlying material onto a target substrate. We show that BB-LIFT of thin and ultrathin (30 and 3 nm) ZrO₂ films is realized only with a “graphene release layer” applied between the Al blister layer and the ZrO₂ donor layer. Without such intercalation, ZrO₂ is inseparable from the blister layer due to the strong oxide bonding with aluminum oxides formed during the preparation. The ZrO₂ transfer was confirmed through high-resolution scanning electron microscopy and energy-dispersive X-ray spectroscopy, affirming the critical role of graphene as a release layer. The promotion of mechanically strong, flexible graphene as a release layer can be generalized in BB-LIFT applications if thin films of fragile, polycrystalline, or amorphous metal oxides must be printed for gas sensors, catalytic, or other applications.