Overcoming Stability and Substrate Adhesion Challenges by Laser-Induced Transfer of MXenes

Despite their metallic conductivity and solution processability, the practical application of MXenes is limited by two persistent challenges: poor adhesion to substrates and low chemical stability in air, which leads to oxidation. Conventional stabilization approaches often involve antioxidant doping or polymer lamination that may compromise electrical conductivity. Here, we tackle these issues by introducing a single-step laser-induced transfer (LIT) process that engineers the MXene-substrate interface to enhance adhesion and chemical stability simultaneously. Our method exploits the spatial confinement of MXene films sandwiched between a glass slide and a polymer substrate. This configuration creates an oxygen-depleted microenvironment, and under laser irradiation allowing for the simultaneous transfer of Ti₃C₂T_x MXene films onto both top and bottom substrates. LIT results in solid-state sintering that, in addition to boosting adhesion, also provides protective effects due to the development of a carbon-rich surface layer. This enhanced adhesion and stability are demonstrated by low sheet resistance, remaining below 25 Ω/sq for MXenes/glass and below 6 Ω/sq for MXenes/TPU after environmental aging for 10 days at 95 ± 2% relative humidity and 40-60 °C. In contrast, conventional direct laser patterning fails to achieve this level of robustness and instead accelerates MXenes decomposition. The suppressed oxidation and mechanical stability enabled by LIT allowed the creation of robust interfaces suitable for electrothermal heaters and proof-of-concept breath sensors. This work establishes laser processing not merely as a patterning tool but also as a powerful interfacial engineering technique, resolving key issues that affect MXene implementation in electronics, sensors, and wearable devices.