Design of micro-fabricated thermal flow-rate sensor for water network monitoring

We report on micro-machined flow-rate sensors as part of autonomous multi-parameter sensing devices for water network monitoring. Three different versions of the flow-rate sensors have been designed, fabricated and experimentally characterized. Those sensors are made of identical micrometric platinum resistors deposited on two different substrates-glass and silicon with and without insulation layer. The sensors were tested under the anemometric operating scheme. They were characterized under a water velocity range from 0 to 3.68 m/s. We highlight the fact that the glass substrate device is more sensitive and less power-consuming than the silicon one under the identical operating condition, which requires further design strategies when using silicon as the substrate material. Experimental results are analyzed with respect to CFD simulations with the Finite Element Method.