Thermoelectric Flow Sensor Integrated Into an Inductively Powered Wireless System

A prototype system has been designed, characterized and built to perform wireless in-situ flow measurements in pipes or other environments where wired connections are not reliable or cannot be realized. The wireless sensor consists of a printed circuit board board inductor, a flow sensor and electronics. An induced electromotive force in the coil by a time varying magnetic field powers the flow sensor and the electronics. The thermal flow sensor uses high temperature processes and chemically inert materials which allow the measurement of a wide array of mediums, even at high temperatures. The prototype system is presented along with characterization of the rigid flow sensor which was used. A flexible flow sensor on a 10-μm polyimide substrate was developed parallel to the wireless system and is currently being integrated into a fully flexible version of the wireless sensor.