A REVIEW ON TYPES OF MEMS THERMAL FLOW SENSORS

Abstract

In different medical, industrial and environmental implementations, there is an important need for fluid flow rate and path sensors. In addition to the crucial criteria for the sensing spectrum of flow parameters (such as intensity, velocity, direction and temperature), the characteristics of the various target gases or liquids to be detected pose challenges to the production of sensors that are accurate, affordable and low-powered. This paper provides a summary of the work that has been performed in recent years on the design and creation of Micro Electromechanical System (MEMS) based flow sensors. MEMS flow sensors can be roughly classified into 3 major groups, namely thermal sensors, piezoresistive sensors and piezoelectric sensors, considering the use of several similar concepts, varied manufacturing processes, analysis techniques and various sensing materials. MEMS flow sensors have a variety of uses, ranging from control of industrial gas flow, environmental flow sensing, marine hydrodynamic sensing, and systems for biomedical flow sensing. MEMS flow sensors are very desirable for commercial and industrial applications due to their small scale, low-cost, high sensitivity, and batch manufacturing compatibility. The multiple MEMS sensors are addressed briefly in the present review article.