High-Sensitivity MEMS Ethanol Gas Sensors Based on Laser-Machined Glass Substrates and Electrospun p-NiO Doped n-V₂O₅ Nanofibers

Nickel-doped V2O5 nanofibers (NiO-V2O5 NFs) were synthesized using electrospinning and integrated onto glass substrates with microelectro mechanical systems (MEMSs) structures. By utilizing UV laser processing, a rapid fabrication of microheaters and interdigitated electrodes (IDEs) was achieved, significantly reducing production time to 1.2 s per MEMS component. Before integrating the material with the MEMS structure, the sensor demonstrated a gas response of 722.6% for 500 ppm ethanol gas at 350 °C, with a reaction time of 48 s, a recovery time of 49 s, and a detection limit of 300 ppb. After combining the NFs with the MEMS structure, the detection limit was improved to 100 ppb, and for 200 ppm ethanol gas at 350 °C, the reaction time and recovery time were 28 and 156 s, respectively. The MEMS structure, fabricated using UV laser machining on a Pt-coated glass substrate, enabled precise and efficient integration of sensing and heating elements. The sensor demonstrated excellent selectivity toward ethanol gas, with a response significantly higher than that for isopropanol and acetone, as well as superior sensitivity, repeatability, and stability across a range of operating temperatures. These findings highlight the potential of this approach for scalable, high-performance ethanol gas detection, and applications in optoelectronic devices.