Frequency profile measurement system for microcantilever-array based gas sensor
Résumé
This paper presents an autonomous instrument based on an array of 8 MEMS micro cantilevers for gas sensor application. The main contribution of this system to the MEMS domain lies on the way the micro cantilevers are optimally exposed to a constant gas flow in a gas cell where the electrical connections to the sensors are done without any wire-bonding. Sensors can therefore be easily changed for another application or for maintenance. Moreover, this complete and autonomous system is able to extract in real time (1 reading/sec) the frequency response of all the MEMS cantilevers by using an innovative mixed-signal processing circuit featuring self-diagnostic and automatic-calibration. Other novelties are the simultaneous piezo-electric excitation of the sensor-array, a low-noise polarization circuit and the detection circuit optimized for piezo-resistive micro cantilevers. From a system point of view this instrument provides the ability to monitor the frequency profiles of an array of resonant gas sensors.
Mots clés
frequency profile measurement system
piezoresistive microcantilever
microcantilever
frequency profile
mixed-signal processing circuit
measurement system
maintenance
wire-bonding
constant gas flow
MEMS microcantilever
microcantilever-array based resonant gas sensor
gas sensor
Gas detectors
Computer architecture
Microprocessors
microsensors
piezoelectric transducers
detection circuit
low-noise polarization circuit
piezoelectric excitation
automatic-calibration
Optical variables measurement
Resonant frequency
Frequency measurement
piezoresistive devices
sensor arrays
calibration
cantilevers
detector circuits
piezoelectricity