Surface Acoustic Wave Sensors

The evolution of modern sensors has come a long way from the first usage of sensors in alarm clocks back in the 1950s to modern sensors used in smart substations. However, the need for more efficient and eco-friendly appliances represents the major two challenges to fabricate a sensor material. Surface acoustic wave (SAW) sensors are now extensively used in various important fields because of their eco-friendly features, better sensitivity, cost factor, fabrication simplicity, scope for wireless operation, and high sensitivity with fast response time. This chapter discusses the concept of SAW sensors and their classification, advancement, mechanism, and types of substrate materials, coupling mode theory, and analysis of wave propagation in SAW gratings. The chapter also discusses the fabrication techniques of SAW sensors and the future trends.