Femtosecond Laser Microfabrication of Ti ₃ C ₂ T _<i>x</i> MXene for Micro-Supercapacitor Electrodes

There is growing interest in using MXene-based materials for electronic and energy storage applications by integrating advanced microfabrication techniques. In this work, we investigate the femtosecond laser micromachining of Ti₃C₂T <i>_x</i> MXene films to enable the direct fabrication of microsupercapacitor (MSC) electrodes with high precision and minimal thermal damage. The influence of pulse energy and number of pulses on the resulting microstructures was systematically analyzed using Scanning Electron Microscopy, Atomic Force Microscopy, Energy Dispersive X-ray Spectroscopy, and Raman spectroscopy. Irradiation with low pulse counts (1-5 pulses at 1010 nJ) produced localized features with depths of 0.5-1.0 μm and minimal redeposition, whereas higher pulse numbers (up to 20,000) yielded features of ∼1.2 μm with partial material removal and resolidified regions. Incubation analysis revealed a progressive reduction in ablation threshold with increasing pulse number. Elemental mapping and Raman spectra confirmed efficient material removal and exposure of the underlying substrate. Using optimized parameters, interdigitated electrodes were fabricated and integrated into planar MSCs, which exhibited an areal capacitance of 19 mF/cm² at 5 mV/s, as well as energy and power densities of 0.45 μWh/cm² and 0.3 mW/cm² at 1 mA/cm², respectively. These results demonstrate that femtosecond laser processing provides a versatile and high-resolution approach for MXene patterning, with strong potential for scalable microdevice fabrication in energy-related technologies.