A new technique to monitor the fluid status of congestive heart failure (CHF) patients in the hospital is proposed and verified in a clinical trial with 8 patients. A wearable Bio-impedance (BioZ) sensor allows a continuous localized measurement which can be complement clinical tools in the hospital. Thanks to the multi-parametric approach and correlation analysis with clinical reference, BioZ is successfully shown as a promising parameter for continuous and wearable CHF patient monitoring application.

An electronic nose based on an array of vibrating doubly clamped beams is proposed. These very high aspect ratio (length/thickness) suspended resonators can be individually functionalized by applying polymer coatings with an inkjet printing approach. The absorption of volatile compounds induces a swelling of the polymers that result in axial stress formation and a shift of the resonance frequency. Furthermore, integrated piezoelectric transducers are used for both actuating the resonators, as well as monitoring their resonance frequency in an oscillator loop. This allows for detection at ppm-level concentrations of low molecular weight volatiles. More importantly, the generic resonant transducers can be individually coated with different polymers to allow for selective detection of volatile compounds. Here, we present the first results demonstrating the obtained selectivity by varying the coating chemistry on identical resonators.

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.

This work presents a multichannel electronic nose system that enables a range of novel applications owing to high sensitivity, low form factor and low power consumption. Each channel is based on a combination of doubly-clamped piezoelectric MEMS resonators and CMOS oscillator-based readout designed in TSMC 0.25 μm technology. Using “application specific” polymer coatings, the individual resonators can be tuned to detect mixtures of volatile organic compounds (VOCs). This system achieves ppm-level theoretical limit of detection for ethanol which paves the way towards a broad range of applications such as personalized health and environment air quality.