Imec and Holst Centre have developed integrated sensing elements for gas detection. The polymer-coated microbridges in high-density arrays can detect ppm-level concentrations of vapors using on-chip integrated read-out techniques. Thanks to the low power consumption (<1 mW/bridge) and small form factor, the technology is ideal for the miniaturization of electronic nose devices.
Imec and Holst Centre have developed a new generation of microbridges with embedded individual piezoelectric shakers in a high-density array with very high fabrication yield. Their design enables rapid coating of a range of absorbents on individual microbridges using commercial inkjet printing technology. The suspended structures vibrate individually, and changes in their modes of vibration (resonances) are monitored as an indication of vapor absorption in their coatings. Due to the very high length-to-thickness ratio of the microbridges, imec and Holst Centre’s gas sensor chip has a high sensitivity to low-concentration vapors. Moreover, by implementing integrated piezoelectric read-out schemes, ultra-low power operation could be demonstrated.
Current work is ongoing to integrate the structures with low-power analog read-out circuits and to demonstrate simultaneous measurements from multiple structures. The low-power miniaturized implementation of an e-nose technology can be used in current applications such as wine and cheese monitoring, but could in the future also help sniff-out human conditions such as asthma, lung cancer, and kidney diseases.