Power-efficient readout circuit for miniaturized electronic nose

A hybrid combination of piezoelectric MEMS resonators and CMOS oscillator readout circuit forms the necessary ingredients of a new generation of electronic nose (e-nose) devices that, owing to their form factor and power consumption, enable a range of novel applications. This paper presents a hybrid low-power, high-resolution e nose system, including the necessary digital interface. An integrated readout was designed for the tracking of resonant frequency shift due to a change in the VOC environment concentration. It interfaces a piezo-actuated functionalized doubly clamped beam resonator that combines low actuation power (μW), high VOC sensitivity but low quality factor in air, large parasitic capacitance and multiple resonance modes. The sensor characteristics translate into a challenging readout design, as high gain-bandwidth product versus low power and low noise are required for optimal detection resolution.