STTR Phase I: Microsensors for In-Situ, Real-Time Detection and Characterization of Toxic Oganic Substances

9810551卡特这个第一阶段小型企业技术转让项目旨在开发一种新型微型传感器，用于现场实时检测有毒有机化学品。建议的微型传感器将能够在现场条件下工作，具有足够的灵敏度以允许高检测率，并具有足够的选择性以防止高的误警率。该传感器基于重量传感和测定分析物独特的光热光谱的组合，并使用波长色散装置和热红外探测器阵列。这种传感技术能够以更高的灵敏度和选择性检测微量有机分析物的存在。在检测过程中，样品被允许与飞焦耳敏感热探测器的涂层表面相互作用/吸附。检测器的表面将覆盖适当的化学层，该化学层优先吸附/与类似于目标分析物的一类化学物质发生反应。当分子吸附在热探测器表面时，可能会发生各种物理变化，例如使用微测辐射热计时电阻的变化，或使用微悬臂梁热探测器时由于吸附诱导应力而引起的弯曲的变化。这一步骤除了提供所需的选择性外，还提供了与最新的化学检测技术相媲美的化学检测灵敏度。为了确定吸附分子的特定身份，利用波长色散装置扫描探测器阵列的宽带波长区域，获得光热光谱。对于被吸附的分析物吸收光子的波长，这些特定探测器像素的温度将与沉积的分析物和吸收的热量成正比。由于不同的像素将暴露在不同的波长下，因此可以确定极其敏感和独特的光热特征响应。化学探测器表面可以通过探测器元件的欧姆加热来再生。微型有毒有机传感器不仅具有极高的灵敏度，而且易于小型化，并可使用标准IC制造技术批量生产，用于大批量商业应用，包括工业过程监测、空气和水污染控制、空气质量监测以及车辆排放监测。

9810551Carter This Phase I Small Business Technology Transfer project aims to develop a novel microsensor for the in-situ, real-time detection of toxic organic chemicals. The proposed microsensor will be capable of operating under field conditions, with sufficient sensitivity to permit high detection rates, and with sufficient selectivity to prevent high false alarm rates. The proposed sensor is based on a combination of gravimetric sensing and the determination of the unique photothermal spectrum of an analyte and utilizes a wavelength dispersive device and a thermal infrared detector array. This sensing technique is capable of detecting the presence of minute amounts of organic analytes with increased sensitivity and selectivity. During the detection process the sample is allowed to interact/adsorb onto the coated surface of femto-joule sensitive thermal detector. The surface of the detector will be coated with an appropriate chemical layer which preferentially adsorbs/reacts with a category of chemicals similar to the target analytes. As molecules adsorb on the thermal detector surface, various physical changes can take place such as changes in the electrical resistance when a microbolometer is used or changes in the bending due to adsorption induced stress when a microcantilever thermal detector is used. This step provides the chemical detection sensitivity comparable to recent chemical detection technologies in addition to providing the required selectivity. In order to determine the specific identity of the adsorbed molecule, a photothermal spectrum is obtained by scanning a broadband wavelength region of the detector array with the aid of a wavelength dispersive device. For the wavelengths at which the adsorbed analyte absorbs photons, the temperature of those particular detector pixels will rise proportional to the amount of analyte deposited and heat absorbed. Since different pixels will be exposed to different wavelengths, an extremely sensitive and unique photothermal signature response can be determined. The chemical detector surface can be regenerated by ohmic heating of the detector element. Miniature toxic organic sensors offer both extremely high sensitivity and are easily miniaturized, and could be readily mass produced using standard IC fabrication technology for use in high volume commercial applications, including industrial process monitoring, air and water pollution control, air quality monitoring, as well as vehicle emission monitoring.