Exploring the resolution of different disk-type chemical sensors

Chemical sensitivities and limits of detection to volatile organic compounds (VOCs) for polymer-coated disk resonators in the gas phase are reported. The dependence of the sensor performance on the device geometry is investigated. The use of rotational inplane modes results in high frequency stabilities, with Allan variances as low as 7.8 times 10^-9 being achieved for 25 mum thick resonators. A limit of detection of 18.3 ppm for toluene was obtained for a 5 mum thick device coated with an only 20 nm thick polymer layer.