Piezoelectric MEMS Sensors and its Applications

The rapid advancement of industry and the acceleration of urbanization have resulted in significant challenges related to the release of harmful and potentially lethal gases, such as CO 2 , H 2 S, NH 3 , CO, NO x , and VOCs (toluene, benzene, xylene) posing serious risks to ecosystems and human health. These pollutants cause severe deterioration of our natural environment, damaging plant life, aquatic ecosystems, and even affecting climate patterns. Additionally, they pose severe health risks, particularly respiratory and cardiovascular illnesses, which threaten human populations exposed to high levels of contamination. Although various monitoring devices exist, they are often expensive and time consuming. Therefore, there is a pressing need for cost-effective, highly sensitive, and selective sensors that offer real-time monitoring of these air pollutants to safeguard both human life and the environment. Piezoelectric MEMS sensors are at the forefront of innovation in precision gas detection heralding a new era of high sensitivity and compact design that is set to transform various applications. These sensors leverage unique attributes, including compact size and low-power consumption, rendering them ideal for widespread deployment in diverse environments allowing for the sensitive detection of various gases. Furthermore, by incorporating advanced materials, such as nanostructured piezoelectric ceramics or polymers, these sensors can enhance sensitivity and selectivity toward specific gases. This chapter aims to provide a comprehensive overview of the principles, design, and applications of piezoelectric MEMS-based gas sensors highlighting recent advancements and the remarkable advantages these sensors offer, including their capacity for real-time monitoring in challenging environments. Additionally, the chapter explores critical issues, including the difficulties associated with sensitivity in detecting low-concentration gases, the effects of environmental factors, and concerns regarding material durability, while also presenting future perspectives for these sensors.