Micro-Electro-Mechanical Systems Gas Sensors for Next-Generation Smart Sensing: From Wafer-Level Fabrication to System-Level Artificial Intelligence Integration

As the demand for ubiquitous environmental monitoring and mobile healthcare grows in the internet of everything era, micro-electromechanical systems (MEMS)-based gas sensors have emerged as a key technology due to their miniaturization and low power consumption.This review provides a comprehensive overview of recent breakthroughs in MEMS gas sensing, ranging from advanced fabrication processes to system-level intelligence.First, we discuss scalable wafer-level manufacturing strategies, such as mask-assisted sputtering and atomic layer deposition, which address the critical challenge of device uniformity.Second, we explore dynamic operation modes, including pulse-driven thermal modulation and micro-light emitting diode photoactivation, which effectively overcome the trade-off between power consumption and selectivity by leveraging kinetic discrimination and room-temperature sensing.Finally, we highlight the system-level integration of large-scale sensor arrays with artificial intelligence algorithms, enabling biomimetic gas discrimination and the precise analysis of complex mixtures.These advancements collectively demonstrate the potential of MEMS gas sensors to evolve from simple transducers into smart, autonomous systems essential for next-generation internet of things applications.