Department of Mechanical and Electrical Engineering, SF&AT, Massey University, Auckland, 0632, New Zealand.
Sci Rep. 2022 Apr 28;12(1):6928. doi: 10.1038/s41598-022-10878-6.
In this work we present a facile method for the fabrication of several capacitive transduction electrodes for sensing applications. To prepare the electrodes, line widths up to 300 [Formula: see text]m were produced on polymethyl methacrylate (PMMA) substrate using a common workshop laser engraving machine. The geometries prepared with the laser ablation process were characterised by optical microscopy for consistency and accuracy. Later, the geometries were coated with functional polymer porous cellulose decorated sensing layer for humidity sensing. The resulting sensors were tested at various relative humidity (RH) levels. In general, good sensing response was produced by the sensors with sensitivities ranging from 0.13 to 2.37 pF/%RH. In ambient conditions the response time of 10 s was noticed for all the fabricated sensors. Moreover, experimental results show that the sensitivity of the fabricated sensors depends highly on the geometry and by changing the electrode geometry sensitivity increases up to 5 times can be achieved with the same sensing layer. The simplicity of the fabrication process and higher sensitivity resulting from the electrode designs is expected to enable the application of the proposed electrodes not only in air quality sensors but also in many other areas such as touch or tactile sensors.
在这项工作中，我们提出了一种制备用于传感应用的几种电容式换能器电极的简便方法。为了制备电极，我们使用常见的车间激光雕刻机在聚甲基丙烯酸甲酯（PMMA）基底上制作了线宽达 300 [Formula: see text]m 的线条。通过光学显微镜对激光烧蚀工艺制备的几何形状进行了一致性和准确性的表征。之后，这些几何形状被功能性聚合物多孔纤维素修饰的传感层覆盖，用于湿度传感。所得传感器在不同的相对湿度（RH）水平下进行了测试。一般来说，传感器产生了良好的传感响应，灵敏度范围从 0.13 到 2.37 pF/%RH。在环境条件下，所有制备的传感器的响应时间均为 10 s。此外，实验结果表明，传感器的灵敏度高度依赖于电极的几何形状，通过改变电极的几何形状，可以在相同的传感层上实现灵敏度提高 5 倍。由于电极设计，制造过程的简单性和更高的灵敏度有望使所提出的电极不仅能够应用于空气质量传感器，而且还能够应用于许多其他领域，如触摸或触觉传感器。
