Pranti Anmona Shabnam, Loof Daniel, Kunz Sebastian, Zielasek Volkmar, Bäumer Marcus, Lang Walter
IMSAS-Institute for Microsensors, -actuators and -systems, University of Bremen, 28359 Bremen, Germany.
IAPC-Institute of Applied and Physical Chemistry, University of Bremen, 28359 Bremen, Germany.
Micromachines (Basel). 2019 Sep 27;10(10):650. doi: 10.3390/mi10100650.
This paper presents a highly sensitive thermoelectric sensor for catalytic combustible gas detection. The sensor contains two low-stress (+176 MPa) membranes of a combination of stoichiometric and silicon-rich silicon nitride that makes them chemically and thermally stable. The complete fabrication process with details, especially the challenges and their solutions, is discussed elaborately. In addition, a comprehensive evaluation of design criteria and a comparative analysis of different sensor designs are performed with respect to the homogeneity of the temperature field on the membrane, power consumption, and thermal sensitivity. Evaluating the respective tradeoffs, the best design is selected. The selected sensor has a linear thermal characteristic with a sensitivity of 6.54 mV/K. Additionally, the temperature profile on the membrane is quite homogeneous (20% root mean standard deviation), which is important for the stability of the catalytic layer. Most importantly, the sensor with a ligand (p-Phenylenediamine (PDA))-linked platinum nanoparticles catalyst shows exceptionally high response to hydrogen gas, i.e., 752 mV at 2% concentration.
本文提出了一种用于催化可燃气体检测的高灵敏度热电传感器。该传感器包含两个由化学计量比和富硅氮化硅组合而成的低应力（+176兆帕）薄膜，这使其具有化学和热稳定性。详细讨论了完整的制造工艺，尤其是其中的挑战及其解决方案。此外，针对膜上温度场的均匀性、功耗和热灵敏度，对设计标准进行了全面评估，并对不同的传感器设计进行了对比分析。在评估各自的权衡因素后，选择了最佳设计。所选传感器具有线性热特性，灵敏度为6.54毫伏/开尔文。此外，膜上的温度分布相当均匀（均方根标准偏差为20%），这对催化层的稳定性很重要。最重要的是，带有配体（对苯二胺（PDA））连接的铂纳米颗粒催化剂的传感器对氢气表现出极高的响应，即在2%浓度下为752毫伏。
