The polymer-coated microbridges in high-density arrays can detect ppm-level concentrations of vapors using on-chip integrated read-out techniques. The demonstrated technology is very suitable for miniaturization of electronic nose devices thanks to the low power consumption (<1 µW/bridge) and small form factor.
Wireless sensor nodes that can chemically detect gaseous compounds are rapidly gaining interest from markets such as food monitoring, healthcare and safety. One of the main gas sensing approaches in uncontrolled environments is the identification of vapors (“smells”) using multiple sensing elements (“receptors”), in a system that is often referred to as an “electronic nose” or “e-nose”. An accurate e-nose requires small, integrated, low-power detectors with individually tuned chemical coatings. Current solutions, like chemi-resistors or quartz crystals are however not scalable or power-efficient enough to build low-power small form factor e-noses.
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. The novel design allows for 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 novel 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. This truly 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.
Imec (imec.be) performs world-leading research in nanoelectronics. Imec leverages its scientific knowledge with the innovative power of its global partnerships in ICT, healthcare and energy. Imec delivers industry-relevant technology solutions. In a unique high-tech environment, its international top talent is committed to providing the building blocks for a better life in a sustainable society. Imec is headquartered in Leuven, Belgium, and has offices in Belgium, the Netherlands, Taiwan, US, China and Japan. Its staff of more than 1,750 people includes over 550 industrial residents and guest researchers. In 2009, imec's revenue (P&L) was 275 million euro.
Imec is a registered trademark for the activities of IMEC International (a legal entity set up under Belgian law as a "stichting van openbaar nut”), imec Belgium (IMEC vzw supported by the Flemish Government), imec the Netherlands (Stichting IMEC Nederland, part of Holst Centre which is supported by the Dutch Government) and imec Taiwan (IMEC Taiwan Co.).
About Holst Centre
Holst Centre (holstcentre.com) is an independent open-innovation R&D centre that develops generic technologies for Wireless Autonomous Transducer Solutions and for Systems-in-Foil. A key feature of Holst Centre is its partnership model with industry and academia around shared roadmaps and programs. It is this kind of cross-fertilization that enables Holst Centre to tune its scientific strategy to industrial needs.
Holst Centre was set up in 2005 by imec (Flanders, Belgium) and TNO (The Netherlands) with support from the Dutch Ministry of Economic Affairs and the Government of Flanders. It is named after Gilles Holst, a Dutch pioneer in Research and Development and first director of Philips Research.
Located on High Tech Campus Eindhoven, Holst Centre benefits from the state-of-the-art on-site facilities. Holst Centre has over 150 employees from around 25 nationalities and a commitment from over 25 industrial partners.
Holst Centre: Koen Snoeckx, Communication Manager, T: +31 40 277 40 91, Mobile: +31 612 719843, koen.snoeckx[.]holstcentre.com.