Sensitivity optimization of micro-machined thermo-resistive flow-rate sensors on silicon substrates

Shaun Ferdous (1, 2, 3) , Sreyash Sarkar (3, 1, 2) , Frederic Marty (1, 3, 2) , Patrick Poulichet (3, 1, 2) , William César (4) , E. Nefzaoui (1, 2, 3) , Tarik Bourouina (3, 1, 2)

1 ESIEE Paris
2 UPE - Université Paris-Est
3 ESYCOM - Electronique, Systèmes de communication et Microsystèmes
4 Fluigent

We report on an optimized micro-machined thermal flow-rate sensor as part of an autonomous multi-parameter sensing device for water network monitoring. The sensor has been optimized under the following constraints: low power consumption and high sensitivity, while employing a large thermal conductivity substrate, namely silicon. The resulting device consists of a platinum resistive heater deposited on a thin silicon pillar ~ 100 μm high and 5 μm wide in the middle of a nearly 100 μm wide cavity. Operated under the anemometric scheme, the reported sensor shows a larger sensitivity in the velocity range up to 1 m/s compared to different sensors based on similar high conductivity substrates such as bulk silicon or silicon membrane with a power consumption of 44 mW. Obtained performances are assessed with both CFD simulation and experimental characterization.

Mots clés: Flow-rate; sensor; Thermal sensor; MEMS; Micro-machined; Water; Silicon; Sensitivity; Flow-rate

Domaines: Thermique [physics.class-ph]; Optique / photonique; Instrumentations et Détecteurs [physics.ins-det]; Micro et nanotechnologies/Microélectronique

Shaun Ferdous, Sreyash Sarkar, Frederic Marty, Patrick Poulichet, William César, et al.. Sensitivity optimization of micro-machined thermo-resistive flow-rate sensors on silicon substrates. Journal of Micromechanics and Microengineering, 2018, 28 (7), ⟨10.1088/1361-6439/aab6bd⟩. ⟨hal-01771102⟩