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Monitoring gas discharges from factories often requires a host of detectors.
Now researchers at the Swiss Federal Institute of Technology in Zurich have
built a microchip that houses three different gas sensors. One acts like a
microscopic silicon springboard, whose vibrations change when it adsorbs
molecules of certain gases. Another has a polymer film that absorbs polarised
molecules such as alcohols—affecting its ability to store charge. A third
sensor measures the temperature change due to molecules evaporating or
condensing on the chip’s surface (Nature, vol 414, p 293).