Novel tube-type LTCC transducers with buried heaters and inner interdigitated electrodes as a platform for gas sensing at various high temperatures
Novel tube-type LTCC transducers with buried heaters and inner interdigitated electrodes as a platform for gas sensing at various high temperatures
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DOI：
10.1016/j.snb.2012.12.119
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发表时间：
2013-12-01
影响因子：
8.4
通讯作者：
Moos, Ralf
中科院分区：
文献类型：
--
作者：
Brandenburg, Annica;Kita, Jaroslaw;Moos, Ralf
研制了一种新型管式传感器传感器，该传感器采用LTCC技术制造，具有内指叉指电极和埋入式加热器结构，可用于700℃以下的高温气体传感。通过有限元模型对埋入式加热器的结构进行优化，得到了敏感层的均匀温度分布，并通过红外相机测量进行了验证。计算了管式换能器在加热和冷却时的热时间常数。未涂覆的换能器的绝缘电阻在96%纯氧化铝衬底的范围内，这些衬底通常用于气体传感器。通过在丝网印刷的内指叉指电极上沉积NOx敏感层，示范了所提出的管状传感器传感器的适用性。通过积累氮氧化物分子作为硝酸盐，这个灵敏的设备就像一个剂量计一样，额外提供了关于实际氮氧化物水平的时间信息。气体在管内流动的传感器几何形状具有新颖的旋转对称性，这对NOx采样特别有利，特别是在不同的流速下。自加热结构允许通过调节温度和存储位置的周期性热再生来改变灵敏度。在350到450摄氏度之间，传感器信号与NOx总量相关，而NOx浓度是从恒定流速下的信号导数获得的。因此，灵敏度随着温度的升高而增加。然而，在650摄氏度的温度下，这种灵敏设备的工作原理就像一个普通的气体传感器，可以直接检测浓度。(C)2013爱思唯尔B.V.保留所有权利。
Novel tube-type sensor transducers manufactured in LTCC technology with inner interdigital electrodes and equipped with buried heater structures were developed for high temperature gas sensing up to 700 degrees C. A homogenoxus temperature distribution of the sensitive layer was achieved by optimization of the structures of the buried heaters by FEM modeling and validated by infrared camera measurements. The thermal time constants of the tubular transducer upon heating and cooling were evaluated. The electrical insulation resistance of the uncoated transducers is in the range of those of 96% pure alumina substrates which are commonly applied for gas sensors. The suitability of the presented tubular sensor transducers was demonstrated exemplarily by depositing a NOx sensitive layer on the screen-printed inner interdigital electrodes. By accumulating NOx molecules as nitrates this sensitive device works like a dosimeter with additionally temporal information about the actual NOx level. The Novel rotational symmetry of the transducer geometry with the gas flowing inside of the tube is particularly advantageous for NOx sampling, especially at varying flow rates. The self-heated structure allows a sensitivity variation by adjusting the temperature and a periodic thermal regeneration of the storage sites. From 350 to 450 degrees C, the sensor signal correlates with the total amount of NOx while the NOx concentration is obtained from the signal derivative at a constant flow rate. Thereby, the sensitivity increases with temperature. However at 650 degrees C, the sensitive device works like a common gas sensor allowing a direct concentration detection. (C) 2013 Elsevier B.V. All rights reserved.