A low-cost integrated micro system for flow velocity and direction measurement

In this paper, we demonstrate a low-cost integrated micro system fabricated by using a micromachining process incorporating with a standard printed circuit technique. The system is used for detecting flow velocity and direction, which is composed of two hot-film sensors and signal processing circuit. Thermal elements of hot-film sensors are deposited on a flexible substrate of polyimide (PI), which is preprinted with electrodes and electronic circuits for the sensors. The advantage of the system is low-cost, flexible capability, easy manufacturing and highly integrating sensors with processing circuits. The wind tunnel experiments are done to validate the feasibility and effectiveness of measuring the flow velocity and direction by the system.